The Effect of Different Cereal Aphid Species on the Performance of Two Coccinellid Predators

摘要

Coccinellid beetles have been studied worldwide for integration with biological aphid control systems but their performance on different cereal aphid prey has not been investigated. A study was conducted to evaluate the relative suitability of five cereal aphid prey species; Rhopalosiphum padi , Metopolophium dirhodum , Sitobion avenae , Schizaphis graminum and Diuraphis noxia on two coccinellid predators; Adonia variegata and Cheilomenes lunata . The five aphid species were separately fed to first instar larvae and newly emerged adult coccinellids in the laboratory. Development and reproduction parameters were quantified. The duration of the immature stages of C. lunata was significantly shorter (F = 1408.34; df = 5, 25; MSE = 0.3; 0.0001) on R. padi (11.7±0.14) and longest on D. noxia (16.2±0.07). The duration for A. variegata larvae was similarly shorter (F = 8718.94; df = 5, 25; MSE = 0.1; 0.0001) on R. Padi (10.2±0.08) and longest on D. noxia (12.1±0.08). The total eggs produced were higher (F = 25648.0; df = 4, 24; MSE= 3.6; 0.0001) when C. lunata was fed with R. padi (740.1±3.00) and lowest on D. noxia (203.0±3.23). A. variegata exhibited nearly a similar trend whereby the total eggs produced were highest (F = 4987.08; df = 4, 24; MSE = 5.5; 0.0001) on R. padi (l655.4±4.83) and lowest on D. noxia (244.2±4.69). The two predators coccinellid species C. lunata and A. variegata are deemed to be efficient predators of R. padi , M. dirhodum and S. avenae and poor on D. noxia and S. graminum .