CALL TO ORDER
Chairman Ralph Bagwell called the meeting to order at 1:00 p.m. at the Holiday Inn Holidome in Monroe, LA. He asked for all participants to introduce themselves. A list of participant names and addresses are attached at the end of this document.
INSECTICIDE EFFICACY - Roy Parker, moderator
Roy Parker began the program with a report results from a 1996 study in Corpus Christi, TX. The test included 11 insecticide applications - 2 for over wintered weevils and 9 in season at 4-day intervals - using Guthion 2L (0.25 lb (AI)/ac), Regent 2.5E (0.05), Vydate CLV (0.25), Phaser 3EC (0.50), Thiodan 2CSO (0.50), Karate 1E (0.03), Baythroid (0.03), Penncap-M 2E (0.50). Spray volume was 6.11 GPA. For the season, Baythroid, Karate, Regent and Vydate had lowest percent punctured squares. Baythroid and Karate also had highest aphid damage ratings compared to other treatments. Aphid damage also was high in the untreated control plots. The negative effect on beneficial natural enemies measured in the study showed Regent had highest percent reduction in total numbers. Parker indicated that the least reduction was with Thiodan. Yields from the untreated control were no different from Karate and Baythroid. Yields in general were greater with Guthion, Regent, and Penncap-M. When economics were considered, Penncap-M, Thiodan, Guthion, and Vydate gave the best return. Baythroid and Karate actually lost money. This study was conducted with varieties DPL 5415 and DPL 33B.
Dick Hardee: Were worms controlled? Parker: No need; there were only low infestations.
Audience Question: Were yield reductions with the synthetic pyrethroids related to aphids? Parker: Yes.
Charles Allen: Why didn't you include malathion? Parker: We had no good way to put out ULV malathion.
Dick Hardee: What is your assessment of Guthion? Parker: In the final analysis, it was acceptable. If you look at the individual dates, it was always on the lower end; however, we were pleasantly surprised looking at the yield data. Guthion will remain in TX recommendations.
Roger Leonard presented 1996 data from 3 boll weevil screening trials in small plot work.
Methyl parathion (0.25), Guthion 2EC (0.25), Guthion 3F (0.25), Bidrin (0.33). After 4 applications there were no differences after the 4th sample. He pointed out that this had been a dry season. In summary, he showed that all samples with the exception of Guthion 2EC were superior to the untreated control. This is consistent with other observations. Leonard suspects that Guthion 2EC has reduced effectiveness because of reduced persistence (more like methyl parathion). Leonard pointed out that Thiodan (0.5 a.i.) has been consistently one of the best performing products in LA. They have observed that it does not flare aphids. At times it appears to suppress aphids. Leonard then showed a data summary from studies conducted over the last 5 years which compared the level of control in relation to the untreated control. His data are summarized below with a listing of insecticide (rate /ac) and the magnitude of difference in boll weevil control in relation to the untreated control: Baythroid (0.03) 14.6 X (fold improvement), Endosulfan (0.375 lb) 9.4 X, Bidrin (0.33 lb) 8.8 X, Vydate (0.25 lb) 7.7 X, Guthion 2L (0.25 lb) 3.6 X. The level of control from Guthion is not that different from that they have seen from methyl parathion. LA will leave Guthion in recommendations.
Dick Hardee: If you were consultant in LA, what would you use? Leonard: If it is Bt cotton in July that has not been treated, a synthetic pyrethroid. Vydate fits in a system. I like to see Vydate used in June because it is systemic and will be better on smaller plants. There also is the nematicidal effect. Thiodan works in some systems where organophosphates have been used because it is in a different class.
Audience Question: What about Bidrin? Leonard: Bidrin may be one option if they have a group of pests. None of these chemistries will be the answer for every case.
Audience Question: What rate for Vydate?: Leonard: Vydate at 0.4 to 0.5 lb/ac is where I feel comfortable.
Blake Layton prefaced his discussion on insecticides with the observation that 1996 spring weevil trap catches were only 10% of the preceding year; however; there were comparable numbers going into over wintering habitat in 1996. Layton indicated that Jeff Willers had questions on susceptibility of weevils. Collections were made, and Dr. Jerry Graves conducted the dosage mortality assays. His 48 hr mortality data (LD-50 values) are summarized below:
Weevil methyl
Source parathion Malathion Karate
(micrograms/weevil)
BW Lab 0.087 0.586 0.029
Bolivar Co. 0.041 0.262 0.016
Grenada Co. 0.04 0.235 0.01
Yazoo Co. 0.057 0.654 0.024
Audience Question: Are you worried about malathion? Jerry Graves: Malathion’s inherent toxicity is not that good, but it does work well in the field.
Layton: Numbers of weevils at the end of 1996 were high, and this was a concern, because in the past it usually took 2 or 3 years for population numbers to increase substantially after a big winter, but the high numbers at end of 1996 may be attributable to low number of sprays made for budworm and the Bt cotton.
William Scott presented results from insecticide studies including spray table studies and field work. He indicated that the level of susceptibility of boll weevil is variable. Insects from the Boll Weevil Lab at Starkville were caged on in plant sleeve cages following applications. Percent mortality at 24 hr. is shown below.
fipronil (0.05) 83
Guthion (0.25) 87
methyl parathion (0.25) 17
Vydate (0.25) 48
Check 2
In field tests with fipronil and Guthion in Weslaco, neither insecticide provided control at 7 day spray intervals. At 3 day spray intervals both Guthion and fipronil did provide protection. Scott noted an inability to impact heavy boll weevil infestations in small plots at weekly spray intervals. Leaf bioassay indicated that mortality by both insecticide treatments doubled between 24 and 48 hr..
Don Johnson summarized studies to evaluate efficacy of insecticides for control of boll weevils in Lonoke. He noted that in AR, there is high boll weevil pressure in only some production areas. Farmers infrequently use methyl parathion, but do use Vydate and Guthion. He recounted comments made a few years ago by Marvin Wall opining that synthetic pyrethroids were not as efficacious as in the past. Johnson indicated that he was keeping an eye on this. He indicated that he shares the concerns of previous speakers with performance of Guthion, but he has no good answer yet. In his spray trials, he keeps a Monday, Friday, Wednesday spray schedule, initiating applications with 15% damage in the field. In his work it takes 2 to 3 applications to get treatment separation, but observations are made 3 to 4 days after all applications. In 1995 trials, treatments included Fury (0.037), Karate (0.028), Baythroid (0.028), fipronil (0.050 and 0.068). In 1996, insecticides included Penncap (0.25), FCR 4545 (0.014), Guthion (0.25), and a Guthion + Orthene combination. Penncap at 0.25 lb (AI)/ac rate has not worked well.. Guthion + Orthene did not show much difference with Guthion alone. With fipronil it was difficult to separate out rates with the low population he dealt with, but it did perform well. Asana efficacy was better at higher rates of 0.03 to 0.042. In his work with Bidrin, he did not see as good results as seen in LA. It did a pretty good job for the first 3 applications, but then the weevils were back. He noted that in 1996 boll weevils appeared to be easier to control than in previous years. In 1996, Guthion was fair but not great on 3 day interval. Synthetic pyrethroids did the best job. In AR, the Insecticide Resistance Management Plan prescribes delaying using synthetic pyrethroids early and using only organophosphates and carbamates in early season.
Fred Donaldson (Bayer) showed results from a cage test with the following treatments: Guthion (0.25), Guthion (0.33), methyl parathion (0.25), Bidrin (0.33). The procedure was to place 100 weevils in cages at 24, 48, 72 hr. after spraying. After 72 hr. weevil mortality determined. After 48 hr. the 0.25 Guthion mortality fell dramatically. Methyl parathion did not perform at all (he pointed out that since it is short lived, this should be expected). He indicated that Guthion is cleared for use up to 0.5, but the 0.25 rate has been recommended and used for 40 yr.. The longer residual observed with Guthion 0.33 was observed out to 72 hr. with over 80% mortality. He stated that perhaps we have tolerance problem where 0.25 lb doesn’t work as well. He asserted that Guthion will not be dropped. It will be manufactured and sold.
Dick Hardee asked what the company planned to do in 1997? Donaldson: Plans are incomplete at this time; these type trials take a lot of time.
Roy Parker showed data from studies in West Texas on performance of insecticides under those low humidity conditions. Field applications were made, leaves collected and taken back to the laboratory. Weevils were confined on the leaves, and mortality data recorded. They compared the following treatments: Endosulfan (Phaser) (0.5), Vydate (0.25), Malathion ULV (12 ounces). He noted that Malathion is controlling boll weevils for over a week. Endosulfan does not look as good as in other trials, but Parker indicated that a longer evaluation time is required rather than what was used in the experiments.
Dick Hardee: If the weevils are not feeding or laying eggs, then what does it matter?
Parker showed data evaluating effects on beneficial natural enemies. These data tend to show that if an insecticide performs well with weevils then it is also detrimental to natural enemies. He pointed out a few trends with some compounds. With minute pirate bugs, the best survival was observed following applications with endosulfan. With Cotesia marginiventris, endosulfan showed little effect. Malathion and Vydate resulted in high mortality for all species tested out to 7 d. Vydate (0.25) killed weevils (70%) even out to 6 days in these low humidity conditions.
Roger Leonard: Has anyone had done any work with generic azinphosmethyl? No response.
Jerry Graves: What is the formulation of ULV malathion, and how the 12 ounce rate related to lbs/ac? Parker: 16 oz is 1.16 lb. a.i.
Roy Parker noted that with the eradication policy in TX, farmers currently have option to use rates for any material in the TX guide.
Audience Question: We are going to have to go back to season long sprays. If they put out their own material how will they be reimbursed? Parker: They will be reimbursed up to 3 applications for up to $2.50/application. They have another option, allow the TX Foundation to treat. If they don't treat, then the foundation will treat. It will be a tough program, but our people did not want to go through the same problems the other regions went through.
Audience Question: What looks like the best rate for fipronil? Blake Layton: The rate for Regent probably will be 0.068 but 0.05 may be enough. An even lower rate of 0.038 may be sufficient with moderate pressure and season long control.
Jerry Graves asked Parker if in West Texas trials the change in insecticide efficacy is noticeable with the different insecticides. Parker: It was hard to tell. There is a higher trap threshold for triggering in-season sprays. The threshold is up to 10 weevils from total of 2 weevils in 8 traps. This is in effect for mid season from a date of approximately first bloom. They appear to have lost a little ground with the higher trigger.
Ray Frisbee pointed out that this strategy was enacted to avoid BAW outbreaks. They may have lost a little ground, but the program will be tightened up. They may go season long with ULV malathion. They have low densities, but they want to get them out. Logistically it will be tough. Parker indicated that they have no choice in Coastal Bend but to give it a try. The trigger will be 2 / trap early and then 8 in mid-season. There will be a total of 8 traps per 40 acres.
Dick Hardee stated that he believed that these traps will not be efficacious.
Aubrey Harris pointed out that in the Mississippi program, farmers aren't given the choice to spray themselves. He thought the TX approach a good story, and he pointed out that he understood why they wanted it. But he asked whether it really does make any difference. Harris says looking at the data there appears to be no difference in effect on beneficial natural enemies, so does it really make any difference?
Parker pointed out that threshold trap numbers also have been changed that trigger applications. He cited work from a couple of consultants who got foundation traps (Hopkins Ag Service), and kept records that showed traps were triggering at fairly low punctured square count.
Dick Hardee said that it had been his experience that wherever traps are placed in the field they fail (that is, they catch extremely low numbers). He asked when has the border trap ever shown what was going on in the field? Parker: The High Plains workers have punctured square data to compare with trap catches. These data are not summarized, however.
An unidentified Audience member from APHIS indicated that he had never been able to correlate trap catches in season with what is going on in mid-season.
INTRODUCTION OF AND REMARKS FROM ADMINISTRATIVE ADVISORS
Ralph Bagwell introduced administrative advisors for SERA-IEG 23, Drs. James Harper and Ray Frisbee.
James Harper provided a brief description of their duties. He represents research and the experiment station directors, and Dr. Frisbee represents extension directors. He expressed his pleasure that these information exchange groups are being used, indicated that he will report back on the good attendance. He noted that participation in the meeting included not only personnel from the experiment stations and extension service, but also USDA - ARS and APHIS, private consultants, industry scientists, and entomologists from 2 countries adds even more diversity to the group. He brought "Greetings" from the directors and indicated that he was looking forward to a good meeting. He complimented Ralph Bagwell on the good agenda indicating that he thought it was "right on".
Ray Frisbee expressed his pleasure in being able to attend. He stated that he thought that this is good meeting to discuss research either from extension and experiment station. He told the group that we don't want to fly by the seat of our pants; we want good data on which to base our programs. He concluded his remarks with the question: What is the reproductive capability and dispersal capability for boll weevil and the probability of reinfestation in eradicated zones? He stated he was looking forward to a good meeting.
MALATHION USE RATE EVALUATION FOR ERADICATION - Bob Jones, Moderator
Bob Jones began his presentation with a short history on the use of ULV applications. ULV probably began with the large scale USDA work beginning with range grasslands with grasshoppers, mosquitoes, fruit flies and boll weevil. USDA has an aircraft application research group that has been available to help with calibration. His experience began in 1970 working with grasshopper. He pointed out the beauty of ULV is the ability to load up several hundred gallons and cover 600 acres. There are many benefits of using ULV beginning with budgetary savings compared with high volume materials (2-3 gallons). During the early MS eradication trial, Guthion ULV was used, but when NC came in, the switch was made to malathion ULV purely from a bid basis. He has tried Penncap-M, but it does have some problems with clogging nozzles. He reported having (unpublished) data on this if anyone wants to look at it. Through the years, ULV malathion has been changed somewhat, and rates have changed. At the beginning, cost was $6.32/gal but now is over $20.00/gal so economics is driving the interest in reduced rates. Aubrey Harris and Jones performed cage studies with ULV in the early 90's with ground equipment. In 1994 they began looking at aircraft. In Stoneville, there is work looking at an air assist ground applicator, and this is showing promise. Along with some of this research on rate work, workers in this area have become more sensitive to potential environmental problems. ULV malathion is an oil based system. There are phenomena with these oils associated with heat and convection currents resulting in loss of the product from the target. With typical use patterns, applications are shut down at 9:00 am in the West range land work; that means applications from dawn to 9:00 am. In the east in some dry land cotton without canopy cover, similar problems have been noted. In high humidity conditions, a lot of your "fines" fail to penetrate (small droplet sizes). Jones indicated that he has been looking through the literature looking for some explanations. He admitted that a field entomologist does have problems with physics, etc. He has started some work with Dan Wolfenbarger and Osana El-Lissy looking at reduced rates from 16 down to a 12 ounce rate. Don Rummel's data had shown no difference. Jones said that his data were comparable. In his next step, he went to Mississippi, but feels he didn't get the same good cooperation that he did in Texas. He ran trials with leaves and evaluated mortality at 48 hr after application. He presented this data at the Texas Technical meeting. Don Rummel was there with his data to substantiate the data. They accepted this rate. The SE group now also has accepted the 12 oz rate after additional work by Eric Villavaso. Depending on the height of the plant it looks like we can go even lower.
Jones presented data from applications of malathion ULV. The % mortality remained at 100% through day 5. On day 6 after 0.57 inches rain (days 9/10 to 9/16/96), mortality was reduced to less than 5%. Jones stated that if there is a rain, you will have to treat again. In August data (8/14 through 8/21/96) he found 100% mortality for 7 days even with heavy dew. Spray card observations had indicated that some malathion was even lost with drop off in the dew. Plans for 1997 include putting a weather station out in the cotton field to get a better feel for the weather. In the Texas lower Rio Grande Valley in Hildago County, under drought condition (no dew), he observed a drop off in % mortality starting on day 4 with mortality going from 100% down to 90% and dropping off further on day 6. On 5/11 to 5/22, mortality in bioassays were 100% for 0, and 2 days; ca 90% at day 4; ca 60 % on day 6; and ca 42% on day 8 and ca 38 % on day 11. Jones said that these data indicate that we are getting longer residual in humid conditions. Beltsville data from the past indicate there is residual out to 20 days. Mississippi State data indicate long residual also. In rangeland work, Jones stated that typically he would only get about 3 days residual.
Jones described work to address the dew issue using RTU Malathion. Chemical analysis of dew samples were performed. Dan Wolfenbarger, based on previous experience, predicted that malathion would be hydrolyzed. Their data showed a good similarity of dew pH in TX and MS. The pH values were between 8 and 9 with over 5 observations from both states. Jones pointed out that ULV malathion does not mix with water, and the hydrolysis factor that was found with RTU Malathion should not be a factor. Jones pointed out that his data was published in the Proceedings from the 1996 Beltwide Cotton Conference (1997).
Jerry Graves asked if there was any experimental work to determine the amount of rain necessary to wash off the ULV malathion. Bob Jones: Don't know how to address this.
Osana El-Lissy replied to the question with the statement that a 1/4 inch rain within 6 hr after application significantly reduced efficacy, but 1/10 inch did not seem to affect efficacy.
Charles Allen asked what if rain was delayed?
Osana El-Lissy responded that the reduction was not as great, but again there was a marked difference between those fields that had not received rain. This paper will be in the proceedings in 1997. He reiterated his earlier statement that ¼ inches of rain within 6 hr. of application or more will reduce efficacy.
Audience Question: What was the rate of the rainfall?
Eric Villavaso: Rainfall of 1/8 inch in less than 15 min will drastically reduce efficacy.
Jerry Graves: If it rains in TX, will you automatically retreat?
Osana El-Lissy: Anytime we receive rainfall within 24 hr. that exceeds 1/4 inch we retreat. Less than that we don't.
Eric Villavaso indicated that he started his work with malathion rate reduction in 1995 when the program was wanting to save dollars. He acknowledged the participation of Joe Mulrooney and Bill McGovern on the project. In the research they worked with both lab and wild weevils. He found that the lab weevils were more tolerant than wild weevils. The work was performed using 2 methods: 1) Petri dish method - one leaf collected immediately after application is placed in a petri dish with 1 weevil, and 2) Mesh Bag - mesh, sleeve cages are placed on plants immediately after application along with 5 weevils. Mortality is determined after 24 and 48 hr. for both methods.
We added the 8 oz rate for comparison, and we dropped 16 in 1996 and added a 4 oz rate.
%Mortality at 48 hr.
1995 1996
4 oz 83 87
8 oz 85 96
12 oz 100 100
16 oz 100
Results from bioassays using the mesh bag cages indicated boll weevil mortality was comparable to that observed in petri-dish bioassays.
Rainfall effects also were evaluated using from 1/20 up to 2/10 inch rainfall. It takes very little rainfall to knock efficacy down as these data show.
12 oz % Mortality
Application 1995 1996
before rain 97 91
after rain 38 55
Based on the data generated in this project and other data indicating the lack of performance difference between 10 ounces and 12 ounces, the Mississippi program is going to use the 10 oz rate.
Bob Jones: In studies with carriers with fipronil, and other products, he couldn't get weevils to go to cotton seed oil. Looking back in the literature, reports showed that cotton seed oil is loaded up with sugar. For ULV oil to stay effective it must remain wet. He also looked at other oils and found that paraffinic oils remain wet. In dipping test with dyes, once refined cotton seed oil and a vegetable oil provided 61.3% penetration with once refined cotton seed but 94% penetration with raw. He measured 12% penetration with ULV. They changed their method to topicals and now are looking for LD-50s with malathion ULV. This work is in collaboration with Jack Ames. The following data are preliminary; the work is ongoing.
Boll Weevil LD-50s
1.7 with crude cotton seed oil
1.1 ULV with Malathion
0.1 ULV with the paraffinic oil, Orchex
Audience Question: What happens on the plant? Jones: It is difficult to get a droplet. They also are getting phytotoxicity with these size droplets. But this work will continue.
Joe Mulrooney reported work with Air Tractor 402 aircraft and a JD 600 with tank taken off and compressor added to atomize droplets. He is using a low volume metering device that meters the concentrations and atomizers. In the research, his group is using 2 bioassay techniques: leaves and the sleeve cage. He also collects deposition data on spray cards. They do residue analyses with gas and liquid chromatography. In studies with fipronil in aerial and ground applications in 1995, rates were 0.028 and 0.025. Mortality ranged from 70 to 75% mortality at 24 hr.; there was no difference between rates. When 0.05 with 0.038 rates were compared, mortality at 12, 36 hr. were 100% for both rates.
In studies with conventional application, they found that mortality to EC formulations dropped off dramatically over time; however, 16 oz /ac malathion held up to 3 DAT where fipronil had fallen off. His data show no differences between malathion at 12 and 16 oz and fipronil at 0.05 in cage studies when weevils were placed in the cages immediately after applications. He pointed out that in cages, weevils have lots of room to move around, and they can avoid treated areas of the plant. In studies with UV protectants, data indicated that residue levels with UV protectant + ULV malathion were higher than residue levels with ULV malathion alone. In other work, Mulrooney reported that oil stays liquid on surface and results in higher mortality with Baythroid compared to water delivery.
Don Johnson: What is this Orchex?
Mulrooney: Orchex is a paraffinic oil made by Exxon and is used in the horticulture industry.
Don Johnson: If we add Orchex to our Baythroid will we get better results?
Mulrooney: Probably.
Eric Villavaso: If mortality is increased with addition of Orchex will it also affect mortality to other animals?
Mulrooney: It will spread.
Gene Burris: Is this similar to Penetrator?
Joe: Wouldn't surprise me.
Keith Holmes, from Rhone Poulenc, reported a study comparing fipronil 2.5 EC and malathion ULV that was conducted in collaboration with Dan and Dee Wolfenbarger 5 km south of the Texas LRGV. All materials were put out by air. The ULV malathion was applied at 0.74 lb A.I. (12 oz) and fipronil (0.05 and 0.025). Materials were applied at 12 oz total volume per acre with fipronil brought up to volume with cotton seed oil. There were 4 applications on 5/22, 5/25, 5/30 and 6/5. Applications began when damage levels reached 10% punctured squares. The 2.5 EC fipronil was brought up to volume with single refined cotton seed oil. Leaf bioassays were made at 0, 24, and 48, hr. after treatment using BW Lab weevils. Punctured square counts were taken and counts of predators and secondary pests also were recorded. Results showed no difference in % dead and moribund weevils after 48 hr. in leaf feeding bioassay following the 1st spray. They found no differences in boll numbers. For predators and secondary pests (whole plant surveys), pirate bugs were no different in fipronil vs malathion although numerically higher numbers in fipronil. All treatments were highly toxic to boll weevils in the leaf bioassay. No significant differences were observed in any measured parameter between the malathion ULV standard and the fipronil treatments.
Current Status of Boll Weevil Eradication in US and Mexico: Frank Carter, moderator
Frank Carter announced the completion of the insect reference book series. He began his boll weevil eradication discussion from a broad national perspective. He has begun a score card on the status of eradication: right now there are 3.8 acres in the eradicated category. There are 1.8 million in active eradication. There are 3 million acres that have passed referendum in LA, AR, TX, MS and TN. When we look at the cotton growers and the meaning of eradication to them, and consider the new Farm Bill with competition in a global economy and transgenic crops, the boll weevil still remains a thorn in our side. He communicated his concerns about the organophosphates (OPs) as a class. It is unknown how the methyl parathion situation will play out. Another unknown is how aggregate risk and common mode of actions will affect OPs with the new food safety law. The "worst first" will be looked at first, and these are the OPs. The regulatory environment also supports boll weevil eradication. So with that overview he started with state reports. He asked that participants share anything of interest with the group. He put up an overhead showing the zones that represented a "living" map, and ongoing plan. He offered copies of maps and a copy of Charles Parker’s National Cotton Council Boll Weevil Action Committee report given at the 1997 Mid-South Farm and Gin Supply Exhibit, in Memphis on March 1, 1997.
Lannie Brashears, provided an update on status of SE. He presented a map showing the 1996 Southeastern BWEP on 3,120,760 cotton acres. The state figures represented total weevils trapped and total number or % of fields sprayed after August 15, 1996. The SE is about 3.1 million acres strong, with about 300,000 in active eradication. Everything from Montgomery AL and SE is completed.
Gary Cunningham, summarized activity with boll weevil eradication in the Southwest US. He showed a transparency which showed that AZ and CA are for all practical purposes free of boll weevils. Two additional areas in NM that must be considered are the Macea Valley and SE NW which has had large increases in weevils in the last 2 years. A trapping history from 1994 through 1996 showed from 84 through early 90s very few weevils, but in the Dona-Ana county, trap counts jumped from 0, 0, 3, 53, 4608, and 19,889 from 1984, 1991, 1993, 1995 and 1996. These growers are now voting for a referendum. Similar trends n trap catches have been observed in Eddy Co. There is cotton south of these areas in Mexico where there are concerns that weevils will move out of these areas.
Frank Carter - Until recently we didn't even have NM on our maps; it shows that the boll weevil won't stay home.
Ron Seward of Tennessee reported that Middle TN is in pretty good shape. He discussed in Area 3 (Zone 1) and the result of the referendum. That vote was 67.8 % in favor of eradication. He provided information on assessments for that region. These are shown below.
Boll Weevil Assessment Rates in Zone 1 - South of Hatchie River
Year 1 $ 10 ==>$11.77 (interest)
2 $ 20
3 $ 30
4 $ 30
5 $ 30
6 $ 30
7 $ 30
Total $180==>$211 (interest)
This arrangement will include a 7 year payback but with 5 year program.
Seward commented on the education program for farmers prior to the vote. Loss assessment data were shown to farmers for the 4 major pests, and this indicated that boll weevils is still the number 1 pest problem in Middle TN. In pulling numbers from 1984 through 1996 the estimates on insecticide costs were about $28 /ac in actual losses to boll weevil from data over the past 17 years. In 1992 through 1996 we looked at historical loss data and found $254/acre losses. These data helped support the $211 cost. Seward said that they hope to get some strong support from the state.
Seward commented on the program they plan. As he understands the program, they are looking at 40 traps on 40 acres with 2 weevils triggering a spray. Their budget includes sufficient funds for 10 diapause applications as long as it takes in the fall. They will wait to initiate program until after Mississippi program proceeds.
Audience Question: Are you going to use 1 trap per acre? Seward: Yes, the standard SE program.
Osana El-Lissy of Texas provided an overview of the current program in that state. Texas is divided into 9 zones: Southern Rolling Plains, Lower Rio Grande Valley, South Texas/Winter Garden, Rolling Plains Central, St. Lawrence, Northern Rolling Plains, Blacklands, High Plains, El Paso/Trans Pecos. Active zones are the Southern Rolling Plains, Rolling Plains Central and the South Texas Winter Garden. The program began in fall 1994 in the Rolling Plains. The plan is to initiate fall diapause in 1997. The Blacklands area will vote in 1997. The High Plains fall diapause program will begin 1998. The Southern Rolling Plains began fall diapause in 1994. Trap data from 1994, 1995 and 1996 trap data were shown. Means of 0.5 weevils/trap were found in 1996 down from 22 /trap in 1995. Slight increases were observed in Fall 1996 (17 weevils/trap). These data indicate 88% lower trap differences in 1994 compared to 1996. El-Lissy commented on condition and changes made for the Texas program. These were:
1996 Vydate C-LV (8.5 fl oz/ac) early season, Phaser (22 fl oz/ac) mid-season in 1996, and then Fyfanon (12 oz) beginning in Oct.
3) Bad weather
Audience Question: What is your trap density? El-Lissy: One trap per 5 acres but 1 trap / 2.5 acres along over wintering habitat.
Blake Layton summarized eradication progress in Mississippi. The state is divided into 4 areas. Area 4 has been in eradication since 1994. Layton reminded the group that this is the region that opted to get out of eradication. He showed trap data indicating "where they were" when they opted to get out. By the end of 1995 there were very few weevils. Only a small percentage of fields required over wintered sprays in 1996.
Results of referenda were reviewed: Votes in Areas 2 and 3 were positive, Area 4 recalled referendum, Area 1 voted against. Areas 4 and 3 will begin in August with a series of up to 10 fall diapause applications. Area 2 will begin in 1998. Another referendum will be held in Area 1 later this year. Costs for each area are shown below.
$155.25 $20 in Area 4 for the grower.
$154.92 $24 in Area 3
$155.95 $22 in Area 2
Area 1 will be $22/ac
Ralph Bagwell made comments on the Louisiana program. The total assessment will be $150/ac for the 5 years. They will start this year with a fall diapause program sometime in August. One hope is "to marry" the TX and SE programs to maximize efficiency. They are in the process of getting everything together.
Don Johnson from Arkansas noted the make-up of the Technical Advisory Board in Arkansas with Dr. Bill Yearian as chair. Mr. Joe Burns is chair of the Grower Board. Arkansas is in the midst of changing the enabling legislation to allow the state to be divided into an additional section. The SE and central portion of the cotton production area will vote in the fall.
Frank Carter summarized programs in Missouri and Oklahoma. In MO the state gave the Department of Agriculture some money to do extensive trapping and selective treatments. The program will begin when neighbors to the south get things in line. In OK plans are getting in line.
Federico Peaez Mejia presented a summary of plans and activity in Mexico. He thanked the group for the invitation. He presented a transparency (in Spanish) on boll weevil work in the in the most important areas of NE, Central N and NW portion of Mexico. Eradication is based on trapping. Research with validation of Catolaccus grandis and Beauveria bassiana is in progress. There are sticky traps and 9,560 pheromone traps in the whole acreage. [Trampeo de 165,000 ha de algodon en 13 entidades]. Funds for the program will come from growers, states and also from the federal government (2 million pesos for boll weevil eradication from federal government).
He briefly described some of the circumstances they will deal with. In the Tamaulipas area they have 2 different production seasons, 20000 ha of cotton in March and 250000 ha in July to make 2 seasons. Below is a listing of cotton hectarage planted in Tamaulipas Spring season in Northern portion (March) vs Southern portion (July)
March in July in
Ha in Northern Southern
1990 11339 20980
1991 73974 31400
1992 5870 8471
1993 3523 19973
1994 25351 55462
1995 48282 51916
1996 22051
Audience Question: How are you going to use Cattolaccus? Mejia: Similar to how you use Crysopa and Tricogramma. We don't see potential problems with hand labor that you have in US.
Role of GPS and Satellite imaging in Boll Weevil Eradication: Don Johnson, moderator
Don Johnson discussed his research with boll weevil trapping in relation to over wintering habitats. Questions he hopes to answer are: Can boll weevil survive in different habitats and what is survival? His crew uses Garmin GPS units to locate weevil traps. When they put a trap out they can get within a few feet of where the trap is located. They have a lot of loss of traps and with the Garmin units they can put the trap back where it fell. They use data loggers to record trap catches. On data analyses he cooperates with Dr. Don Scott who uses GRASS software and Unix computer. Aerial photographs are used to aid them in habitat descriptions. In the future he is looking at software available for PC including Arc View and Grassland. A fairly large computer with expanded RAM is needed for these analyses. Remote sensing of area allows them to see the major over wintering habitats in a crop production area. Even for regular management practices. He has mapped out the weevil population trap catches which showed colors for the different trap catches and movement of the weevils from the habitat. One of the things that he has figured is how far the boll weevil moves from the habitat. He sees the same thing in his data, that the boll weevil moves about 1/2 mile from its over wintering habitat. They have traps laid out in grids with habitat descriptions associated with each trap. He showed data from 1994 and 1995. He pointed out that in general there were trap catches in every habitat in 1995. By 1996 his data indicated that numbers were reduced significantly after the winter 1995-6. Overall the over wintering habitats are more separated and segregated in the northern counties of the state. He hopes to use GIS technology to identify habitat in efforts to identify where limited area suppression tactics may be implemented.
Dick Hardee: How do you know boll weevil moves 1/2 mile? Johnson: If you look at the movement in the spring, Dick, and you are not catching weevils in the center (contouring the populations out); we think that weevils move only 1/2 mile.
Hardee: We catch more weevils 1 to 3 miles from cotton than close to cotton. What we don't know is how far these weevils move. I'm not arguing with you but I think there is a lot of things we don't know.
Audience Question: How often did you check your traps? Johnson: Every 2 weeks.
Glenn Wiygul passed out maps from the Mississippi Boll Weevil Management Corporation, from voluntary trapping program and from Mike Williams. He discussed the trapping program and some of the tools, including satellite imaging that he uses. He also reviewed what GIS can do, emphasizing that it is data management tool. He showed an example of Mississippi BWMC maps and the first year data from 1992. He said that they were producing maps at the section level and that using satellite images is the most viable means of recognizing cotton production fields. LANDSAT 4 and 5, which was set up by NASA is where they get their information. There are other satellites and the price is now coming down. A year ago an image cost $4400 for one scene 30 meter resolution across 7 wavelengths [EOSAT]. [showed drawings from John R. Jensen's book]. Older satellite images can be bought for $200 (over a year old). An advantage of satellite images is the reduced cost to the program. Cotton fields can be located, and images are transportable to GIS. Longitude and latitude are available from these maps. [Showed images from MS and Washington DC showing a 30 m resolution and 10 m resolution]. [Showed images from cotton fields in the Delta]. Going to the area on the map and making sure that cotton is being grown there is called ground truthing. This has become a real buzz word. [Showed an image of Columbus, MS - 1/2 of 100miX100mi image]. Distance measurement is easily performed with the appropriate software. What the software does is it puts all the frequency ranges into 100 compartments. Once an area has been ground truthed, it is possible to tell which fields are cotton. They then set cotton to be a particular color. They then have the computer to find the other similar areas in the compartment with a particular color. The more compartments you have the better. They plan to overlay the satellite data with maps from the Mississippi Dept. of Transportation Road Maps. They will use bar codes to keep up with trap data. He showed an example of a bar code with County, Farmer's name, trap number and perhaps a date. He showed satellite images showing AR and MS in the delta region with cotton in red. It is possible to get longitude and latitude of a field and then give those to a pilot. He believes that this will allow reductions in application errors. Also with use of global positioning units, they can identify where traps are.
Ralph Bagwell: How are you identifying a cotton field? Is it hard to tell the difference between a cotton and soybean field? Wiygul: No, let me tell you what we will do in MS. The satellite image will get 90% accurate leaving 10%. We will make 10 sq. mile images and send them out to the farmer and let them verify that these are cotton fields. We also will send these to county agents and also make a cash award available to someone who might find a field that we haven't found. If it is questionable we send someone out for ground truth.
Ralph Bagwell: How large will cotton have to be? Wiygul: These images were done in mid June, so undoubtedly if they were done n July or August they would be easier.
Ralph Bagwell: What about spring? Wiygul: I don't think that you have to use satellite images from the year you are working with. I think we an use last year's images. There is not that much change from year to year, and with the 2 or 3 tier approach we will find it.
Audience member: Under the new Farm Bill, I think you are wrong with new rotations.
Audience member: Why cant you pick up the other 10% . Wiygul: Flooded fields and weedy fields mask the cotton.
Ralph Bagwell: I have been told that soybeans are difficult. Wiygul: There are a lot of operator problems in this software, and it takes a lot of time to learn how to do this.
Don Johnson: What kind of accuracy are you getting with GIS? Wiygul: This varies from satellite image to satellite image. Most of these are right on. We've had a few that are a few meters off.
Audience member: Is there a specific longitude and latitude reading that you use? Wiygul: Center of fields. One more comment... NASA will launch a new LANDSAT this year with 1m resolution with multispectral capacity. This means that images from old LANDSAT will be cheaper.
TEXAS REPORT: Boll weevil trapping in TX uses hand held GPS units. They use self correcting ScoutMaster II. They use FM frequency technology type with the $300 for the receiver and $300 for receiving the signal. One unit is capable of mapping 20,000 acres. They have to map all these fields right as they are being planting. Accuracy is corrected down to 1 to 5 meters. These data are used for trapping and for aerial application. The whole idea started in AZ back in 1980s. They wanted to design an expert system to sort, calculate and make treatment systems and send out information to the aerial applicator for sprays which then sends data back to us after application is made. They use data from the bar code system. They are able to go back and analyze this information using Map Info as the data base. [Showed map of spring emergence in San Angelo area]. The most important thing is that they don't have many companies that provide the FM frequency. Costs are going down rapidly. Cost per unit is $900 to $1200 that will cover 20,000 acres.
Mike Williams reminded the group that cotton loss estimates are performed every year. Even with boll weevils out of the SE US, loss to this insect is still rated to be the 2nd highest in the US (even without those SE states). He presented 1995 and 1996 data showing trap captures. The data show peaks indicating the fall build up that must be dealt with. In his opinion there was little winter kill. In data showing seasonal means there were more weevils in the west delta. In the NE part of MS, he emphasized how the program must capitalize on the low numbers that we had.
George Mullendore: They were smart enough to put worm traps in this area. We have these data on the Internet.
DIAPAUSE, Terry Wagner, moderator:
a. Induction of Diapause and Decision Rules for Fall Diapause Applications
Terry Wagner: Diapause is really an interesting series of processes that includes prediapause, diapause induction, diapause maintenance and diapause termination. The environmental token stimuli that are received by prediapause individuals are sometimes confusing. A series of complex processes are involved with diapause, and the series of processes are important for when, and how long they remain in it. If you don't have a mentor that really understands diapause, it will make it difficult to get started in this. We are very fortunate to have the facilities at Mississippi State that allow us to simulate dynamic photo periods and temperatures to simulate any environment in the world. We got the bugs worked out of our system in 1989. In the mid 1980s I think that I was the only one studying diapause. There has been renewed interest lately, and this is related to the eradication effort. Most of the money spent on traditional programs has been associated with fall diapause. When we should start and stop and what the spray interval should be are the areas where I have directed my research. Most other research has been when to start and intervals. When to stop is an interesting area, and there is a great deal of debate on this area. With that brief introduction I'll show you some of my work before moving on to other speakers.
The first part of the work began in 1989 was basic environmental conditions, the token stimuli for the egg and larval stages. This animal monitors its environment throughout its life cycle from egg throughout adult. It needs to see a dynamic unfolding environment. Through this fall period what portion of population begins to go in diapause through this period. Through a series of experiments we focused on photoperiod (a key environmental stimulus for most insects). This is true for boll weevil, too; not the only one, but it is very important. In the research, only wild weevils were used. He has never have gotten good data from lab weevils. Green egg punctured squares are collected from the plant. He feeds squares to the emerged adults. Insects used in research are limited to square reared, square fed weevils. Squares put weevils into diapause very well, bolls will do so equally well, but squares will too. Essentially what you see is a relationship between a diapause induced population and day length (hr.). It's very easy to go to something that does have meaning. Day length can be predicted at any Julian date for any area. You can then predict percent diapause for any area. [Graphic showing Julian Date and percent diapause]. Early August some go into diapause, and as you move into the fall a greater percentage goes in.
Audience member: Where is crop phenology? Wagner: Blake, where are we? Blake Layton: Some fields are at cutout some at peak bloom.
Dick Hardee: Terry are you saying that regardless of what food source, temp, cloudiness etc. day length is the main stimulator? Wagner: Some factors in the host are independent. The food source is a contributor. But day length alone will give you a good guide. Why is day length important? Because we can apply this model to the rest the Belt. This model is available or anyone. If you can give me you day length by Julian Date, I can run the model for your area. I can give you the information to give you information on diapause induction.
Audience question: Where were these insects collected and plant stages? Wagner: These animals were collected prior to when these points were plotted. They were put into simulated environments that they would see if they had stayed in the field. We plotted it out on date of emergence giving the eradication program a window of opportunity .
Phil Tugwell: Would you comment on work by Mary Ann Rankin of University of Texas who has worked on links between dispersal flight and diapause. Wagner: With some animals the mechanisms are the same for dispersal and diapause. We would suspect that boll weevil would do the same thing. But dispersal starts before we see diapause syndrome.
Audience Question: Does this assume that boll weevils are same in the southern part of the Belt? Wagner: If you apply the model in different parts of the Belt you would see this. I ran the model for weevils from LRGV to see what the model says, and what the literature says. Indeed you get lower percentages during the time of the late crop months, and what information is available seems to coincide with what the model says. This suggests that the animal behaves similarly in different parts of the Belt. It does not say that it is not adapted differently from different areas.
Audience Comment: We see high percentage of diapause of weevils in High Plains at the time when we see low diapause in South Texas. Wagner: You have to correspond the period of time with the day length.
Jerry Graves: I think it does vary with photoperiod. That is what is Newsom's data say.
Wagner: If you know of software that generates day length for any longitude and latitude for Julian Day, I’d be interested in it. Day length is a function of latitude and longitude. How much time is required for the animal to develop the diapause syndrome? If we determine this, it will give us an idea of how long the animal stays in the field. How long will they continue to feed, and how temperatures affect this. Assumptions are related to the development of the fat body -- it must feed to develop the fat body. It doesn't need this for atrophy of gonads. We also assumed that taking food out of it would be a function of temperature. Temperature would influence how long it would take to funnel these resources into the fat body. General perception is 2 weeks. Well, generally that is correct, but we are interested in developing a population model. We did a series of experiments with Cotton Incorporated funds. We have developed another model. Some of these results were a surprise to us. We did a series of experiments with square fed animals. We collected punctured squares with advanced environment so that we were inducing diapause (advanced temperatures and photo periods) Diapause syndrome is developed during the adult stage. We put them in static temperatures to see how long it took to get weevils into developing the diapause syndrome (fully enlarged fat body and atrophied gonads). This was diapause intensification from a morphological standpoint. Earlier experiments showed that temperature did not affect diapause syndrome. If they are diapause induced they will go into diapause regardless of temperature. This ranged from 7.2 days at 36o C to 26.2 days at 14.9o C for females. For males this ranged from 7.8 days at 36o to 27.3 days at 14.9o C. Females required less time than males. Diapause induced males almost always produce sperm. They don't apparently produce pheromone. Some of their energy is used to produce sperm. Females do not expend energy in this way.
Audience Question: Is there any information on how long they stay in the field after they reach diapause syndrome? Wagner: We are assuming that once that they have acquired the diapause syndrome, there is no advantage in staying in the field.
Audience Question: Do diapausing weevils respond to grandlure? Wagner: We take weevils out of pheromone traps and very few have the diapause syndrome. We take them out of traps after they have stayed there only a couple hours or less. These were fed, and many went into diapause.
Audience Comment: Mitchell put traps in the middle of cotton field. He dissected the weevils out of traps and weevils in the field. He found 2 times as many were in diapause in the field than in the trap.
Wagner: We've never seen that.
Tom Plato: We did a test. In trap collections of late September and October, weevils were dissected by High Plains Lab (Rummel). Anywhere in the test, there were between 40 and 80% of weevils in firm diapause.
Bob Jones: I have dissected weevils out of traps. I found partially fat weevils in traps but never found fully fat weevils in traps.
Wagner: Part of the discrepancy may be the techniques used.
Wagner: These data are the foundation of the model development. How fast it will develop the diapause syndrome and what portion of the population has reached this at this time. In a simulation model used a rate function with temperature. [0.171 (5.8 d) @ 33.7o C for males]
Audience Question: Are we on the wrong track if we are looking at high temperatures?
Wagner: Let me go on, I have 15 years worth of temperature data, and I averaged across temperatures. Simulations were run for animals emerging 1 and 15 Aug., 1 and 15 Sept. and 1 and 15 Oct.. How long will it take these animals to acquire the diapause syndrome. The fastest times which were generally based on warmest temperatures and slowest times based on coldest temperature and the average of the years. I showed data for females only. As you move from August to October averages move from 5.8, 6.7, 7.3, 9.1, 14.4 and 23 days for the dates above. This is for 50% of population. These data can be used to make decisions about spray intervals. For fastest simulations in October and assuming the animals have foods we actually get 8.8 days that 50% of females can develop the diapause syndrome. If you have Indian summer in October, and it can find food, it will go into diapause in a hurry. It may be that it is not as important the type of winter we have, but what type of late fall we have and what kind of food is available.
Let's couple the first model with proportion of animals going into diapause with time required. In looking at just the diapause induced animals, 18% males will acquire diapause syndrome August 1. On October 16 you are putting 98% in. [Aug.. 1: 18% M and 5% F, Aug. 16: 45% M and 18% F, Sept. 1: 76% M and 53% F, Sept. 16: 91% M and 83% F, Oct. 1: 96.6 M and 94.9 F , October 16: 98% and 98% on Oct.. 16].
Aubrey Harris: In our MS plans we will initiate diapause applications earlier (Aug. 1) and go at a closer interval. We run out of money by early Oct. if we do that. Looks like we can’t have any food out there or we have to keep spraying. Looks like this shoots down what we are doing in MS.
Wagner: If there is no food out there, then it is stupid to spray. It is critical to pay attention what is going on in Oct. We must concentrate on those fields with food. Should we take out early Aug. weevils (early in, late out)? My personal belief is that if you put a weevil in "sure enough" diapause, he probably will make it regardless and come out late. We must worry about food availability in October.
Dick Hardee: In planning for fall diapause program you must make a decision before Oct.. If you have $10 to spend would you rather spend it in 1st week of Aug. or 3rd week of Oct.?
Wagner: You take the biology the best you can, and you must compromise by the constraints of the program.
Dick Hardee: Answer the question based on if you were a farmer.
Wagner: I've given you the data -- you make the decision.
Dick Hardee: Give us an answer.
Jerry Graves: The females are what we have to worry about, and it looks like we can look at mid-August. If we have fields cutting out in July. In fields that are green. Published data show this.
Wagner: You're right, you can take data that you want to select. Move it back after 15 Aug.; looks like you can get in trouble. I wouldn't necessarily say that females are more important than males.
Gerald McKibben: Timing of emergence is also important.
Wagner: Data suggest early in late out. Should you spend money on these? If this is true, it is money well spent.
Jerry Graves: Rummel’s data shows first in first out. But I tend to agree with you.
Wagner: Boll weevils in firm diapause come out beginning in March through August; I don't know.
Jerry Graves: Programs that have done it, have done it with these starting dates.
Mike Williams: Mated or not mated for over winter? Wagner: Diapause induced males and females will mate. We see large numbers mated.
b. Winter Mortality
Theresa Singer presented summaries of dissections of fall pheromone trapped weevils. Weevils were freezer- killed and stored in isopropyl alcohol. They evaluated weevils for fat content, sex, and reproductive condition. Ca. 12 to 30 weevils were dissected for each collection date. Collections were begun 3 September. By mid-September 50% of weevils were considered in the diapause condition. Over 90% of dissected weevils were in diapause by late September. She noted that the weevils are active in warm days and not on cold days.
In cold bath experiments to evaluate temperatures and conditions that would lead to weevil death, she used weevils from field collected squares and from pheromone traps. Adults were held in incubators with 18.3:15:6o C with a light:dark photoperiod of 11:13 hr. For the study she used coffee cans that were empty, or contained leaf or grass substrate which was either dry or wet. Weevils were exposed to 0o, -5o and -10o C in the cold bath which contained a 50:50 antifreeze:water mixture. Weevils were exposed over several different exposure periods, and mortality was determined. Percent survival was highest when boll weevils were in cans with dry leaf litter. In empty cans at -10o C most weevils died. Following the cold baths, weevils were dissected. Greater numbers of weevils with moderate to high fat content survived better at lower temperatures.
Dick Hardee: extremely dry and extremely cold for long periods of time is the best way of killing boll weevil. Singer: Your interpretation of what is dry that is important.
Mike Williams: What does the air temperature have to be to kill weevils? Singer: We must know where these weevils are and look at that in relation to soil temperature.
Tina Gray Teague summarized data collected in NE Arkansas during the winters of 1995-96 and 1996-97. Temperature measurements were made a in a variety of different habitats to contrast ambient air temperatures with those temperatures to which boll weevils likely would be exposed in their over wintering quarters. Data from 1996 pheromone trap catches associated with those habitat types were reported. The study site was the edge of a dense patch of oak and elm trees on the ASU Research Farm in Jonesboro. Small, matchbox-size temperature loggers inside waterproof canisters were used to monitor temperatures (Hobo Temp temperature logger, Onset Computer Corp. Pocasset, MA). Three temperature loggers were placed in each different habitat types including (1) dense (4") leaf litter under trees ca. 20 ft from the field margin, (2) tall unmowed Bermuda grass, (3) and bare ground. Conditions in January and February in 1996 and 1997 were such that weevil mortality due to freezing would not have been high in areas with deep leaf litter compared to more marginal habitats. The litter provided insulation to protect from cold temperatures. In 1996, pheromone trap catches from fields adjacent to high quality habitat were 10 to 40 fold higher than those associated with low quality habitats. Other pheromone trapping data from NE Arkansas showed similar trends indicating that the winter of 1995-6 severely impacted boll weevil over wintering survival, particularly in low quality habitats. Trap data indicate that weevil mortality was not as high in areas with deep leaf litter compared to grass habitats. The temperature monitoring program and trapping will continue in efforts to make accurate qualitative and quantitative appraisals of habitats required for successful over winter survival by diapausing boll weevils. Additional data from drainage assessments and farmer/consultant surveys also will used to make these determinations. Information on habitat quality and boll weevil history will be used to link the appropriate suppression tactic with the expected threat of weevils.
c. Other Biological Studies:
Gerald McKibben summarized his work with a new design of olfactometer. With this design, boll weevil response to grandlure or other materials is assessed using average distance traveled (cm) up the tube. He also is looking at plant parts. Filtered air is blown across parts. He has found that boll weevils are more attracted to a single cotton flower than a single square. They also are attracted to leaves. With this technique he can quantify attraction to groups of plant parts. He has found 2 squares are more attractive than 1 flower than 1 square than 2 leaves than an untreated control. Weevils tested are 8, 10, & 12 days old. His data indicate that weevils are most attractive at 10 days. Little is known anything about the incidence of diapause and attractiveness of pheromone. Eric Villavaso has expressed interest in "ironing out" the response to pheromone dependent on their physiological state. A question that McKibben will be focusing on is how do weevils find thick dry cover? There may be a chemical basis for locating favorable habitat. He will be looking for volatiles in ground trash and leaf litter.
Boll Weevil Eradication: Methods and Alternative Tactics: Blake Layton, moderator
a. Alternative tactics in high density areas:
Blake Layton I would like to structure this discussion with high densities first then low densities. Then I would like to discuss startup and terminations along with in-season triggers. One of my concerns is the decline in APHIS personnel allocated to work with eradication programs.
Are there any areas presently considering a spring startup. NO
Next, is the use of BWACTs in high density areas. I know that BWACTs have been used in sensitive areas. Lannie, the question is what is use in the SE.
Lannie Brashier: Currently we are using them on limited scale in low density areas in a cleanup method. We are using them in combination with traps. We trap early and base placement on those data. In 1995 we had a few thousand acres. We did use them in 1996 and plan to do so in 1997. In Chambers County in AL we found that we didn't get the control we needed in early season.
Blake Layton: What is the cost?
Tom Plato: Depending on amount of product going in .... goes about $6 @ 2 installations. First of April for 1st installation.
Ron Seward: What is the trapping density to determine this? Tom Plato: A trap every 300 ft between sticks with sticks every 100 ft.
Tom Plato: Lannie, in 1995 in Lee, Macon, Russel and Chambers Co. you were able to reduce pop below threshold levels.
Lannie Brashier: In Chambers Co. we just used BWACT until July, but by August found higher numbers.
Tom Plato: You put these on 202 fields in 1996.
Lannie Brashier: we used them in 1996 but didn't have as good experience in 1995. The data ... we found by 5 Aug. we found 55% of fields with reproduction. And 2/3 of fields we had to use insecticide application. We had fields where we didn't get weevil detection.
Blake Layton: If we exclude low density areas, is there any area where they will be used. NO.
Lannie Brashier: In 1995 weevil levels were overwhelming for sticks.
b. Eradication in Low Weevil Density Areas:
Tina Gray Teague summarized results from studies in NE Arkansas with alternative tactics for suppression. N.P. Tugwell collaborates on this work that is funded by state support dollars from Cotton Incorporated as well as Core CI funds. The boll weevil eradication research group in Arkansas has investigated an array of alternative methods for cutting costs and reducing environmental impacts of boll weevil eradication efforts. Most methodologies exploit the powerful boll weevil pheromone which is used in conjunction with trap crops, strip-sprays, bait sticks, and conventional pheromone traps. Each approach has a potential niche in an eradication program. Research by Don Johnson and his group allow identification of sites where the boll weevil would be abundant during the winter and spring. The AR approach is to attack the weevil as it enters and emerges from its winter refuge. It is believed that the use of alternative tactics at the winter refuge site is most appropriate where overall weevil infestations are low and populations are least likely to survive the winter. The area that this approach is most appropriate lies in NE Arkansas, where during the last referendum, farmers overwhelmingly (>80%) voted against eradication.
Trap crop research involves transplanting greenhouse grown plants set using high speed transplanters. Using this method, it has been possible get 1/3 grown squares in our trap crop 3 to 4 weeks ahead of the direct-seeded comical crop. This research is summarized in the Proceedings of the Beltwide Cotton Conference for both 1996 and 1997. Additional work involves evaluation of bait sticks in very low density areas. Evaluations of efforts from last year will begin this spring by using an extensive trapping program in sites where standard bait sticks, bait sticks without toxin, and no bait sticks were installed last spring and fall. Trapping in these areas will begin in the next couple of weeks. In other research, the potential of using plant growth regulators such as Prep to remove boll weevil food in late summer/early fall is being evaluated. Much of the approach we propose for low density areas relies heavily on use of mist blower. This is proving to be an indispensable part of the suppression tactics under consideration. The contribution of APHIS for lending 2 mist blowers for use in the AR research project was acknowledged.
Ron Seward: I've been on the job for 7 wk. We passed the referendum in the SW but we probably will not be able to pass the referendum in the NW TN area. Tennessee grower comments from that area indicate that "If I don't have any weevils I am not going to spend money to help my neighbor". We will be looking at a strong diapause program. We will be looking at pin head applications, dimilin applications, bait sticks, and fall diapause applications. Based on my experience in an earlier research program, up to 4 fall diapause program and 2 pinhead sprays may be something to look at. We are brainstorming on ways to reduce costs. We did a survey on what our farmers would pay. Farmers don't know how much they have lost to boll weevil. I think in that area $5.00 to $7.00 in insecticide costs. Under $20/ac, certainly.
Jeff House of Missouri indicated that the planners in his state definitely are looking at fall diapause. A project with the Department of Agriculture and Cotton Incorporated is focused on looking at their hot spots.
Audience Question: Do you have an idea what farmers are spending on weevils. House: No, I am associated with the research end.
Osana El-Lissy of Texas said that for fall diapause in High Plains they are just waiting to see.
In South TX they have adopted the approach to limit the potential for secondary pest outbreak by allowing the farmer the option to make his own applications. They are coordinating the participation of consultants who have agreed to send information related to action threshold.
c. Potential Impact of Changes Made on Eradication Effort
Blake Layton: We don't want to underestimate the effects that Bt cotton will have on eradication. Does anyone have any comments about this?
Aubrey Harris: Some of the new insecticides will have the same impact such as Tracer because of its selectivity.
Gerald McKibben: Were there not instances in MS this past year where farmers had not sprayed for boll weevils before if they had Bt cotton?
George Mullendore: I believe that Bt cotton is what has convinced our farmers that they need eradication.
Roy Parker: Is anyone suggesting that Bt cotton be planted in Eradication Zones?
Blake Layton: Roy, we generally are suggesting that they increase their planting of Bt cotton to reduce their risk from caterpillars. Our variety tests are also showing that these varieties are also economically advantageous.
General Discussion:
Starting and Stopping Fall Diapause Sprays -
Aubrey Harris: Growers were told that the program would start on 1st week of August, and growers based their vote on that vs starting on the 3rd wk of August. We are budgeted for up to 10 diapause sprays. I would like to see emphasis on more end of season termination on NAWF = 5.
Bob Jones: The way they handled this in GA was to have pay incentive to have the crop terminated by a certain date using Prep, Dropp and then early stalk destruction.
Blake Layton: Another thing is the emphasis on field unit supervisors education to teach them on how to determine a field does not need to be treated.
Lannie Brashier: I am hesitant to do this.
Roy Parker: We need some way to help terminate a crop earlier. We have additional data to show that Roundup applications can help farmer if harvest is delayed. It will keep down re-growth.
Audience Comment: Anything that breaks that food chain will be an advantage in fall diapause. Timely termination is a key.
Roy Parker : In Texas an incentive was established that for every week they got a $2.50 rebate per week for up to 3 weeks. That Roundup for regrowth control has be timed properly related to 20% open boll.
Roy suggested that this type approach might be included in research efforts.
Gerald McKibben: Once the population density is sufficiently low, the traps are used for eliminating the final weevils. We know the traps play a big role in eliminating the final weevils. We feel that this is an essential control. Mass trapping is vital. A trap ration of 1 to 1 is $15/year but 1 to 5 is $10/ year.
Audience Question: If you have fewer traps, do you get less quality trapping?
Lannie Brashier: The 1 to 1 gives you a lot of buffer. A few traps knocked down you still get trapping. Trappers also prefer to run 1 to 1. Trap density will be much less with larger field sizes.
Gerald McKibben: We considered 1 to 5 in our first budget meetings, but we decided that it was better to go ahead to give the trappers experience.
Mid Season Triggers:
Blake: Most triggers are 1 weevil per 4 acres.
Lannie Brashier: SE uses 5 weevils per 40 acre field. We did try 10 in 1988; we decided that it was on the high side.
Roy: What you did was spray most of the fields.
Lannie Brashier: Probably 30% of fields. Started 15 Aug.. If you are willing to stay the course and not shut them off you will be OK. Those traps pick up weevils quicker than you can see damage in the fields.
Alternative Insecticides
Roy Parker: No endosulfan or Vydate will be used in TX in 1997.
Aubrey Harris: For the Mississippi Technical Advisory Committee, the issue is higher cost and reduced efficacy. If we plant Bt cotton to solve tobacco budworm, and with the knowledge that Tracer is available, we have chosen not to complicate the problem by introducing the option of alternative choices of insecticides as a substitution for ULV malathion.
Roy Parker: We don't want to complicate the problem, but the data from Mandy English indicate susceptibility to key natural enemies. A lot of this came up before we knew we'd have Tracer.
Aubrey Harris: For us, it is tobacco budworm not beet armyworm that has us worried.
Audience question: What is the time frame for the TX program?
Roy Parker: It’s an open ended program really.
Aubrey Harris: Mississippi is 5 years, and if we don't get it done in 5 years, we will have a problem.
Blake Layton: I am concerned about the lack of experience that will be available for the new areas.
Lannie Brashier: I don't share that as much as you do. Mistakes will be made regardless. We are committed to giving MS 2 people.
Gary Cunningham: The bottom line is that with the SE program, federal APHIS personnel were greatly involved; however, with right sizing, our role will be reduced. We will be providing technical expertise. The other states will be asking for 1 APHIS person/state.
Blake Layton: Field unit supervisor positions are critical, and I am concerned about these.
Ralph Bagwell: I have a question about movement of seed cotton / modules from one region to another. What have the other regions have done?
Blake Layton: AL has put a quarantine?
Lannie Brashier: The biggest problem area will be custom harvesters and that type equipment moving from region to region.
Ralph Bagwell: We have problems with movements of seed cotton.
George Mullendorf. I need information on effect of malathion on plant bug. Please send it to me. Also sources for malathion.
Tom Plato: Chemanova.
SPECIAL PRESENTATION by Deborah McPartlan (Texas)
Deborah McPartlan: This is a token of our appreciation to someone who is a real friend to boll weevil eradication -- National Boll Weevil Equipment Specialist, Mr. James Moody. Jimmy worked long hours in the LRGV for us, and we are particularly grateful to him. We have a plaque for him. Jimmy, please come up and accept this.
Jimmy Moody: This has been one of the most rewarding jobs I've had with the government. If you hear APHIS personnel speak about hating to see the foundations take over, that is why.
CONCLUDING REMARKS : Ralph Bagwell, Chairman
Ralph Bagwell: I want to end this meeting with a general consensus on some important issues:
Guthion efficacy: Most people have recognized that Guthion was a very effective product. Most every state has indicated that it will be recommended, and it is considered to give comparable control as methyl parathion.
Malathion Use Rates: Mississippi will be using 10 oz; we will not be reducing from 12 in LA.
When should diapause sprays be initiated? Look historically at what has worked is where we seem to be.
When can diapause sprays be terminated? As long as there is any green material left in the field then spray it.
Diapause application intervals: 7 day intervals considering no rainfall.
Following this discussion, a general business session was begun with nominations for secretary for 1998. Charles Allen from the University of Arkansas, Monticello was nominated and was accepted by the group by acclamation. The current secretary will succeed Bagwell as Chair. Possible locations for the 1998 meeting were discussed. Vicksburg, MS was suggested and was acceptable to the group. Meeting was adjourned at noon.
Respectfully submitted,
Tina Gray Teague,
1997 SERA-IEG 23 Secretary
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| Charles Allen | Cooperative Extension
University of Arkansas PO Box 3508 Monticello, AR 71656 |
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| John Andries | LDAF
PO Box 3596 Baton Rouge, LA 70821 |
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| Ralph Bagwell | 212 Macon Ridge Road
Winnsboro, LA 71295 |
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| Robert E. Boyd | USDA-APHIS-PPQ
501 Magazine St. New Orleans, LA |
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| A.L. Brashier | 3270 Montezuma Road
Montgomery, AL 36106 |
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| Gene Burris | Northeast Research Station
PO Box 438 St. Joseph, LA 71366 |
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| Frank Carter | National Cotton Council
1918 N. Parkway Memphis, TN 38112 |
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| Eric Castner | 302 Goodwood Circle
Lafayette, LA 70508 |
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| Monty Christian | PO Box 343
Cotton Center, TX 79021 |
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| Grady Coburn | PO Box 302
Cheneyville, LA 71325 |
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| Gary L. Cunningham | USDA-APHIS
4700 River Road Unit 138, Riverdale, MD 20737 |
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| Joe Davidson | USDA-APHIS-PPQ
3505 Boca Chica #360 Brownsville, TX 78521 |
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| Fred Donaldson | Bayer Corp
4200 Aspen Court Pineville, LA 71360 |
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| Doug Duty | 24 Jana Drive
Monroe, LA 71203-2736 |
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| Osana El-Lissy | PO Box 5089
Abilene, TX 79608 |
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| Marion Farris | LCES
PO Box 1364 Coushatta, LA 71019-1364 |
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| Ray Frisbie | Dept. of Entomology
Texas A&M University College Station, TX 77843 |
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| Jerry Graves | Dept. of Entomology
402 Life Sciences Bldg. Baton Rouge, LA 70803 |
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| Frank S. Guillot | Dept of Entomology
402 Life Sciences Bldg. Baton Rouge, LA 70803 |
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| D.D. Hardee | USDA-ARS-SIMRU
PO Box 346 Stoneville, MS 38776 |
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| Aubrey Harris | MSU Delta Research and Ext. Center
PO Box 197 Stoneville,MS 38776 |
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| Keith Holmes | 1012 W. Oak Estates
San Antonio, TX 78258 |
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| Bob Jones | USDA APHIS
Boll Weevil Methods MS State, MS 39762 |
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| Donald R. Johnson | Cooperative Extension Service
PO Box 391 Little Rock, AR 72203 |
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| Blake Layton | Box 9775
MS State, MS 39762 |
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| Roger Leonard | Macon Ridge Station
212 Macon Ridge Road Winnsboro, LA 71295 |
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| Gus Lorenz | Cooperative Extension Service
PO Box 391 Little Rock, AR 72203 |
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| Gerald McKibben | PO Box 5367
MS State, MS 39762 |
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| Phil McNally | Bayer Corp.
8400 Hawthorn Road Kansas City, MO 64127 |
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| Deborah McPartlan | USDA
TX Boll Weevil Eradication Program 3103 Oldham Lane #B Abilene, TX 79602 |
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| Federico Peaez Mejia | 940 ?? Valenzuela 127
Cogoacan, Mexico |
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| Steve Micinski | Red River Research Station
PO Box 8550 Bossier City, LA 71113-8550 |
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| Jimmy L. Moody | USDA
901 Hillsboro Street Oxford, NC 27565 |
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| George P. Mullendore | 9776
MS State, MS 39762 |
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| Joe Mulrooney | PO Box 36
Stoneville, MS 38776 |
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| Boyd Padgett | 212 Macon Ridge Road
Winnsboro, LA 71295 |
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| Roy Parker | Rt. 2 Box 589
Corpus Christi, TX 78406 |
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| Dave Parvin | Mississippi State University
PO Box 5187 MS State, MS 39762 |
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| Kenneth R. Pierce | USDA
Rt. 6 Box 464-F Texarkana, TX 75501 |
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| Carol Pinnell-Alison | 6562 Main Street
Winnsboro, LA 71295 |
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| Jim Plato | Plato Industries
2020 Holmes Road Houston, TX 77045 |
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| Tom Plato | Plato Industries
2020 Holmes Road Houston, TX 77045 |
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| John Pyzner | PO Box 488
Calhoun, LA 71225 |
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| Bert Quisumbing | Hercon Environmental
Aberdeen Road Emigsville, PA 17318-0467 |
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| Craig Roussel | PO Box 3118
Baton Rouge, LA 70821-3118 |
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| William Scott | PO Box 346
Stoneville, MS 38776 |
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| Ron Seward | 605 Airways Blvd.
Jackson, TN 38301 |
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| Richard Shaw | PO Box 1638
Madison, MS 39130 |
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| Theresa L. Singer | CES,UA
PO Box 357 2001 Hwy. 70E Lonoke, AR 72086 |
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| Stephen Stringer | PO Box 778
Farmerville, LA 71241 |
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| Tina Gray Teague | P. O. Box 2340
State University, AR 72467 |
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| Phil Tugwell | 321 Entomology
Fayetteville, AR 72701 |
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| Jesus Vargas | PO Box 5109
Brownsville, TX 78523 |
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| Eric J. Villavaso | USDA-ARS
PO Box 5367 MS State, MS 39762 |
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| Terry Wagner | USDA-ARS
PO Box 5367 MS State, MS 39762 |
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| Michael R. Williams | Box 9775
MS State, MS 39762 |
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| W.C. Yearian | 321 Ag. Bldg.
Univ. of AR Fayetteville, AR 72701 |
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| Henry Yang | PO Box 12014
Research Triangle Park, NC 27709 |
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