Effect of simultaneous use of the entomopathogenic fungus, Beauveria bassiana (Ascomycota, Hypocreales) and different cultivars of wheat on the Russian wheat aphid, Diuraphis noxia (Hem.: Aphididae)

The effect of simultaneous use of entomopathogenic fungus, Beauveria bassiana and different cultivars of wheat was investigated on Russian wheat aphid (RWA), Diuraphis noxia, under laboratory conditions (25 ± 1 °C, 85 % RH and a photoperiod of 16L: 8D). Thirty experimental units of each cultivar were prepared and each replicate was consisted of one first nymphal instar. The nymphs were produced by the adults infected with LC10 of the fungus on each cultivar. The number of nymphs produced by each treated aphid was daily recorded until death. The data were prepared and analyzed according to the two-sex life table using TWOSEX-MSChart software. In the current research, the lowest value of LC10 of the DEBI008 isolate was belonging to the Arg cultivar; however, there was no significant variation among different wheat cultivars on the RWA offspring. Also, the duration of nymphal instar, with exception of the first nymphal instar, had no significant difference between the control and fungal treatments. Only the Alvand cultivar caused to prolong the adult longevity gained from fungus-infected aphids compared to the Arg and Pishtaz cultivars. The results showed that the wheat cultivars influenced direct pathogenicity of the fungus on the RWA.