Effect of temperature on biological attributes and predatory potential of Harmonia dimidiata (Fab.) (Coleoptera: Coccinellidae) fed on Rhopalosiphum padi aphid

Abstract

The influence of temperature on the biology and prey consumption potential of ladybird beetle, Harmonia dimidiata (Fab.) (Coleoptera: Coccinellidae), fed on Rhopalosiphum padi aphid was investigated. The results showed that temperature had significant effect on developmental duration, survival and prey consumption potential of different stages. The duration of different stages was highest at low temperature and shortest at high temperature levels. Although the predator completed its development at all tested temperatures but extreme low and high temperature adversely affected the survival of immature stages. At high temperature level, the female beetle could not produce eggs. The lower temperature threshold level for different stages were in the range of (-1.25 ⁰C to - 0 °C) and thermal constant k values for different stages were in the range of (17.86 ⁰D to 142.86 ⁰D). The results indicate that optimum temperature for rearing H. dimidiata was 24 ±1 °C. The predatory ladybird beetle can be utilized as a part of integrated pest management program for the management aphid pests.