The Effect of Metarhizium flavoviride and Phenylacetonitrile on Food Consumption and the Daily Behavior of the Gregarious Nymphs of Schistocerca gregaria

Metarhizium flavoviride, strain Mfl5 spores were formulated in cotton seed oil at a concentration of 0.9 X 107 spores/ml and applied topically under the pronotal shield of the fourth nymphal instars of the desert locust Schistocerca gregaria. The amount of food consumed was calculated daily for six days where all treated nymphs were died. The reduction in the amount of food consumed was more than 50% compared to the amount consumed by non-treated nymphs, and that treated with oil only. Also the effect of integration of the adult aggregation pheromone major component, phenylacetonitrile, with the entomopathogenic fungus M. flavoviride on the daily behaviour of the desert locust nymphs was assessed. It was found that phenylacetonitrile alone increased the activity of the stimulated nymphs. While the fungus treated ones were more static, those under PAN stimulation spend most of the time moving and consuming more food. Nymphs treated with M. flavoviride in the presence of PAN stimuli are the most static ones and the least in moving and food consumption.