Effect of sublethal concentration of Beauveria bassiana on cellular energy allocation in the predatory bug, Andrallus spinidens Fabricius (Hem.: Pentatomidae)

The predatory bug, Andrallus spinidens Fabricius (Hemiptera: Pentatomidae), is a potential biological control agent of lepidopterous larvae in the rice fields of Iran. In the present research, the sublethal effects of the entopmopathogenic fungus, Beauveria bassiana were studied on the cellular energy allocation (CEA) of this predator. Conidia suspensions were prepared in five concentrations of 104, 105, 106,107 and 108 conidia ml-1.Fifth-instar nymphs of A. spinidens were immersed in fungal suspensions for 10 seconds. After bioassay and data analysis, the effect of LC30 of B. bassiana were investigated at 25±2 °C, 60%±10% relative humidity and a photoperiod of 16:8 h (L: D). The amounts of available energy (including carbohydrate, glycogen, lipid and protein), energy consumption and cellular energy allocation were estimated. No significant difference was observed in the amounts of available and consumption energies in the treated insects (68.53±0.028 and 6.10±0.01 j/insect, respectively) compared with control (79.61±0.03 and 6.63±0.01 j/insect, respectively). Estimation of cellular energy allocation showed that treated bugs had a lower amount of energy (11.22±0.75 j/insect) compared with control (12±0.37 j/insect), but difference did not cause statistically significant. According to the present study, the sublethal concentrationof B. bassiana (3×105 conidia ml-1) was not caused any significant effect on the biochemical parameters of A. spinidens.