Effect of entomopathogenic fungi of the genus Lecanicillium on behavioral reactions and average per-day fecundity of the predatory bug Orius laevigatus Fieber (Heteroptera, Anthocoridae)

Abstract

The results of studying the effect of spores and mycelium of entomopathogenic fungi of the genus Lecanicillium on the behavioral responses of predatory bugs Orius laevigatus and their fecundity are provided. In a laboratory experiment, the location of the bug adults was assessed after 24 hours, as well as the average daily fecundity of females with a free choice between a bean leaf with agar (control) and a bean leaf with sporulating fungal mycelium (experiment). It was found that the neutral reaction prevailed in the behavior of the bugs. The repellent reaction of predators was caused by the mycelium of three strains: Vl 29 (L. lecanii), ARSEF 2332 (L. dimorphum), Vit 71 (L. attenuatum); the index of aggregation ranged from -40.7 to -50 (P<0.05). Strain Vl 5 (L. lecanii), index of aggregation+43.3, caused a significant attractive reaction. The strains causing a repellant reaction of bugs did not affect the average per-day fecundity of females. Only two strains Vl 72 of L. muscarium and Vl 79 of L. dimorphum caused a significant decrease in the fecundity of O. laevigatus, while the reaction of bugs to the mycelium of these strains was neutral. In the absence of a negative effect of fungi on the fecundity of bugs, the combined use of these biological agents may be promising.