Compatibility of the entomopathogenic fungus Lecanicillium longisporum (Petch) Zare & Gams with the predatory midge Aphidoletes aphidimyza Rondani (Diptera: Cecidomyiidae)

The combined use of the predatory midge Aphidoletes aphidimyza Rondani (Diptera: Cecidomyiidae) and the entomopathogenic fungus Lecanicillium longisporum (Petch) Zare & Gams., biocontrol agents of the green peach aphid Myzus persicae, was evaluated in a semi-greenhouse setting. Results from this experiment showed a statistically significant additive effect of these organisms in controlling aphid populations: a higher reduction of aphid populations in cages with fungus plus predator was observed compared to predator-only or fungus-only treatments. Lab experiments evaluating interactions between A. aphidimyza and L. longisporum showed no effect of the fungus on survival of the predator when sprayed directly on four-day old larvae. However, feeding on infected aphids decreased fitness proxies of the midge. Prey consumption was not affected by the presence of infected aphids and infected aphids did not affect the oviposition site selection by Aphidoletes. Based on these findings, the combined use of predator and fungus is recommended.