Fourth National IPM Symposium


Fourth National IPM
Symposium/Workshop
2003



 Session: Biorational Insecticides – Selectivity and Importance in IPM Programs
Wednesday 1:45 PM - 5:00 PM
Organizer(s):
Isaac Ishaaya (vpisha@int.gov.il )
Phyllis G Weintraub (phyllisw@int.gov.il)


The following presentations are in this session:

1:45 PM - 2:05 PM Bacillus thuringiensis, an important agent in IPM programs Mark E Whalon


2:05 PM - 2:25 PM Novaluron (Rimon), a novel IGR – selectivity and importance in IPM programs Isaac Ishaaya
    Isaac Ishaaya*, Avner Barazani**, Svetlana Kontsedalov*, and A. Rami Horowitz***

    *Department of Entomology, Agricultural research Organization, The Volcani Center, Bet Dagan 50250; **Makhteshim Chemical Works, Beer Sheva; ***Department of Entomology, Agricultural Research Organization, Gilat Research Center, M.P.Negev 85280; Israel.
    E-mail: vpisha@int.gov.il

    The search for potent acylureas has led to the development of new compounds such as chlorfluazuron, teflubenzuron, lufenuron and others, which are far more potent than diflubenzuron on various agricultural pests. One of the recent benzoylphenyl urea, which is in the process of commercialization and use worldwide is novaluron {Rimon EC-10, 1-[chloro-4-(1,1,2-trifluoro-methoxyethoxy) phenyl]-3-(2,6-difluoro-benzoyl)urea}. It acts by both ingestion and contact. It is a powerful suppressor of lepidopteran larvae such as Spodoptera littoralis and Helicoverpa armigera (by ingestion) and whiteflies such as Bemisia tabaci and Trialeurodes vaporariorum (by contact). The compound has translaminar activity affecting thereby leafminers such as Liriomyza huidobrensis. Its residual activity, under field conditions, ranges between 10 and 30 days depending on environmental conditions. Our studies revealed that the compound has no appreciable effect on parasitoids and phytoseiid mites, and has probably a mild effect on other natural enemies. Hence, it can be considered an important component in IPM programs. No appreciable resistance to novaluron was observed in a field strain of S. littoralis. A very resistant colony of B. tabaci to pyriproxyfen (about 2000-fold) showed no appreciable cross-resistance to novaluron. Field colonies of B. tabaci pressurized with acetamiprid or thiamethoxam, resulting in 30- to 50-fold resistance to acetamiprid and thiamethoxam, has no cross-resistance to novaluron. These results are of a special interest, indicating possible rotation between novaluron, pyriproxyfen and neonicotinoids in insecticide resistance management programs. The selectivity of novaluron and its suitability in resistance management render this compound an important agent in pest management programs for controlling whiteflies and lepidopterans.



2:25 PM - 2:45 PM Botanical Insecticides, important agents in IPM programs Murray B. Isman
    Murray B. Isman, Faculty of Agricultural Sciences, University of British Columbia, Vancouver, Canada V6T 1Z4. murray.isman@ubc.ca

    Botanical insecticides, all but forgotten with the advent of synthetic insecticides in the 1950s and 1960s, are re-establishing their place as useful tools for integrated pest management in agricultural and urban contexts. Two botanical insecticides predating synthetic insecticides, pyrethrum and rotenone, continue to be used, although the latter is losing favor in most markets. These have been joined by newer botanicals; neem in the early 1990s and plant essential oils in the past five years. Pyrethrins (in pyrethrum) and monoterpenoids (in essential oils) are neurotoxic to insects, acting as contact insecticides with fast knockdown properties. Rotenone is a mitochondrial poison whereas azadirachtin (from neem) is an IGR (ecdysone antagonist) and antifeedant. In general terms all of these botanicals are relatively safe to the user and consumers, but their limited persistence under field conditions often necessitates repeated applications. As to their compatibility in IPM programs, natural enemies and pollinators are susceptible to poisoning by pyrethrum, essential oils and to a lesser extent, neem, although the short half-lives of these insecticides in the field should minimize perturbation of natural enemy populations. The Food Quality Protection Act is creating new opportunities for reduced risk pesticides, including botanicals. On the other hand, botanicals tend to be relatively expensive and face stiff competition from other products in the marketplace. The greatest impact of botanicals will be in organic food production systems, plus other agricultural and urban contexts where there is a heavy premium placed on protection of human health and the environment.



2:45 PM - 3:05 PM IPM in forestry using rational insecticides and biological control Arthur Retnakaran


3:30 PM - 3:50 PM The use of biorational insecticides in vegetable crops Phyllis W. Weintraub
    PHYLLIS G. WEINTRAUB, Research Entomologist, Agricultural Research Organization, Gilat Research Center, D.N. Negev, 85280, Israel.
    phyllisw@volcani.agri.gov.il

    Although the use of IPM has been promoted for some years, the use of bio-rational insecticides in vegetable crops has an inconsistent record. Two cropping systems, celery and potatoes, are compared and case studies for both crops are presented. Celery growers in the US and Israel have adapted and use a wide variety of biorational insecticides. US Potato growers, on the other hand, lag behind their European counterparts in the use of biorational insecticides. Reasons for these differences in adaptation may be the result of lack of education programs, convincing research, and economic issues.



3:50 PM - 4:10 PM Ecdysteroids, selectivity and importance in IPM programs Guy Smagghe
    Guy Smagghe1, Pilar Medina2, Marcela Schneider1, Elisa Viñuela2

    1 Laboratory of Agrozoology, Department of Crop Protection, University of Gent, B-9000 Ghent, Belgium. 2 Unidad de Protección de Cultivos, E.T.S.I. Agrónomos, E-28040 Madrid, Spain.

    Toxicity bioassays indicated that the ecdysone agonists like tebufenozide and methoxyfenzodie show high activity against a target pest insect, the beet armyworm Spodoptera exigua (Lepidoptera). Treated caterpillars showed premature induction of molting followed by death within 2 days. This high toxicity in Lepidoptera concurs with a high affinity to bind on the target ecdysone receptor in competition with 3H-ponasterone A. In addition, we report on biological activity bioassays with three natural enemies, the spined soldier bug Podisus maculiventris (Heteroptera), the green lacewing Chrysoperla carnea (Neuroptera) and the parasitoid wasp Hyposoter didymator (Hymenoptera). The profile of a 14C-isotope of these products to accumulate in the insect body of these beneficials is followed. This pharmacokinetic information together with possible differences at the target ecdysone receptor are discussed to explain the non-toxicity of these ecdysone agonists in these beneficial insects. As such, these products are considered safe and useful in IPM.



4:10 PM - 4:30 PM Natural enemy interactions with biorational insecticides in citrus Beth Grafton-Cardwell


4:30 PM - 4:50 PM The Use of non-conventional insecticides in ornamentals in Canada Graeme Murphy