Abstract

Our investigation in the region of Jijel revealed that whiteflies are the predominant greenhouses pests; they are polyphagous, moreover, some species can transmit many plant viruses. The treatment method is based on the systematic use of insecticides that have side effects on both the consumer and the farmer. The objective of this study was to evaluate the use of biological control in situ and in vitro as an alternative method by using an entomopathogenic fungus Verticillium lecanii. In vitro experiments showed that the fungus was active during all stages of development of the insect, Trialeurodes vaporariorum Westwood (Homoptera: Aleyrodidae): Eggs (LD₅₀ = 0.59. 10⁷ spores / ml) larvae (LD₅₀ = 0.5. 10³ spores / ml) and adults. Our results showed the influence of spore concentration, contact time and relative humidity on the development of the parasite to reach an efficient anti-larval effect of 100%.

Key words: Verticillium lecanii, Trialeurodes vaporariorum, entomopathogenic, alleyrodidae, whitefly,  biological control.