Compatibility and study effect of some insecticides and essential oils with entomopathogenic fungus, Lecanicillium longisporum in laboratory condition

Pathogenic fungi are one of the factors for the insect pest control. Conidia viability of fungi، changes because of the effect of environmental factors and chemical insecticides that are used to protect plants. In this study، the effect of insecticides; imidacloprid and acetamiprid، andessential oils of the mint، Mentha spicata L. (Lamiaceae)، cumin، Cuminum cyminum L. (Apiaceae) and lemon sole، Citrus aurantifolia L. (Rutaceae) on mycelial growth and conidial germination rate of Lecanicillium longisporum was studied. Concentrations of insecticides and essential oils used in the study were as 250 μl/l (0. 5 MC)، 500 μl/l (MC) and 1000 μl/l (2 MC)، respectively. This experiment was conducted in a completely randomized design and the effect of insecticides and essential oils with four replicates at three concentrations of 27 ± 1°C on SDA medium was examined. Results showed that the effects of three essential oils and two insecticides on growth parameters of entomopathogenic fungus compared to controls was significant at p<0. 01. Cumin essential oil and acetamiprid had the highest، lemon and mint essential oils had the lowest percentage inhibition of mycelial growth and fungus conidial germination. The results showed that this fungus resistant to lemon essential oil and to cumin essential oil and acetamiprid are sensitive. It was found that by increasing the percent inhibition of mycelial growth of fungus، conidial production rate in each petri dish was significantly reduced. Lemon and mint essential oils have been investigated with regard to their significant effect and low risk to humans and the environment than chemical insecticides، could be used in integrated pest control program with the fungus or as a model for the construction of new pesticides with high compatibility.