This study is the first report about the toxicity of pesticides to the mycophagous predator, I. koebelei, of powdery mildew of agricultural crops. Pesticides we tested are composed of synthetic and environmental-friendly products and being used conventionally for the control of insect or microbial pests on cucumber in Korea. our study was conducted to determine the relative toxicities of several pesticides used in Korea cucumber production to mycophagous natural enemy, I. koebelei and to provide a background for implementation of integrated powdery mildew management programs. Based on IOBC classification, three insecticides, bifenthrin + imidacloprid, acetamiprid + indoxacarb, acetamiprid + etopheprox are classified as having a Class 4 (harmful). Spiromesifen showed the low toxicity to the survival and the fecundity of I. koebelei when this chemical had been exposed to 3rd larva or newly emerged adult via feeding with cucumber powdery mildew. However, pyriproxyfen not only decreased the fecundity of female adult but also strongly prohibited from pupation. Many commercial biological or botanical pesticides can restrict the population of I. koebelei. However, Q pact (a.i. Ampelomyces quisqualis 94013), Top seed (a.i. Paenibacillus polymyxa AC-1), BT one (Bacillus thuringiensis) and Solbitchae (insecticidal microorganism) had no toxicity to I. koebelei when this chemical had been exposed to 3rd larva or newly emerged adult feeding with cucumber powdery mildew.

Identifying effective chemical control agents of Bemisia tabaci biotype B and Q is an important step toward IPM strategy. Until 2008, only 10 chemical agents were registered for B. tabaci. From the laboratory screening of 60 insect- and acaricides, 18 chemicals for egg, 10 for nymph and 8 for adult stage were found effective (>90% mortality). Also ten chemicals were less toxic to B. tabaci. Among ten chemicals, some conventional insecticides need further careful resistance monitoring. Field trials with some of the selected chemicals open the possibility to chemical control of B. tabaci biotype Q. Further consideration of non-target effects and resistance development has to be exerted before registration process.