Efficacy of some entomopathogenic fungi against Aphis fabae Scopoli (Hemiptera: Aphididae)

Abstract

The present study was carried out to evaluate the efficacy of three different conidial concentrations (1x10(4), 1x10(5), and 1x10(6) conidia/ml) of five isolates (TR-04, TR-05, TR-07, TR-08, and TR-10) of Lecanicillium muscarium, one isolate (TR-01) of Simplicillium lamellicola, a commercial bioinsecticide Verticillium lecanii, and a synthetic insecticide (Imidacloprid) against the black bean aphid, Aphis fabae Scopoli (Hemiptera: Aphididae) under laboratory conditions. Bioassays were conducted in Petri dishes, and insect mortality rate was recorded daily. The LT50 values (days) of the isolates at 1x10(6) conidia/ml were 2.96 (TR-05), 3.08 (TR-10), 3.21 (TR-07), 3.45 (TR-01), 3.73 (TR-04), and 3.83 (TR-08), while they were 4.37 and 0.73 for the commercial bioinsecticide and insecticide, respectively. The LT90 values (days) of the same conidial concentrations of the isolates attained 4.30 (TR-07), 4.35 (TR-05), 4.80 (TR-10), 5.15 (TR-04), 5.25 (TR-01), 6.06 (TR-08), 6.72 (commercial bioinsecticide), and 2.36 (insecticide). The 1x10(5) and 10(6) conidia/ml concentrations of all the entomopathogenic fungal isolates tested against A. fabae caused >90% mortality by the end of the seventh day. It is concluded that both conidial concentrations of these isolates had significant potential to control black bean aphid.