Efficacy of Entomopathogenic Fungal Isolates Amesia cymbiformis and Acrophialophora jodhpurensis on the Biology of Black Bean Aphid, Aphis fabae

Abstract

Black bean aphid, Aphis fabae is one of the most important economic and widespread insects worldwide. In the current study, the presence of entomopathogenic fungi was detected from soil samples taken from orchards planted with Vicia faba L from four different locations in Najaf Governorate (Najaf city province, Haidariyah, Abbasiya and Mashkhab). Pathogenicity studies showed that isolates of A. cymbiformis and A. jodhpurensis produced the highest mortality rate on the sixth larval stage of the wax moth insect Galleria mellonella, (47.2 and 46.2%, respectively), 5 days after treatment. The results obtained showed that the concentration of 2×10⁷ conidia/ml of each of A. cymbiformis and A. jodhpurensis gave the highest mortality rate of 78.6 and 77.5%, respectively, 5 days after treatment. The results also showed that there were significant differences in the mortality rates among the different insect stages. The first nymphal stage suffered the highest mortality rate of 65 and 64%, 5 days after treatment with the concentration of 2×10⁶ conidia/ml of both fungal entomopathogens A. cymbiformis and A. jodhpurensis, respectively. The results obtained showed a decrease in the rate of nymph production of black bean aphid when using conidial suspension at a concentration of 2×10⁶ conidia/ml sterile distilled water for both entomopathogenic fungi, 5 days after treatment.

Keywords:

Aphis fabae, entomopathogenic fungi, Galleria bait method Amesia cymbiformis, Acrophialophora jodhpurensis.