Temperature dependent development of Harmonia axyridis Pallas (Col.: Coccinellidae) on two prey: Aphis fabae Scopoli and Dysaphis crataegi (Kaltenbach) (Hem.: Aphididae)

Abstract: Development of the predator Harmonia axyridis was studied at four constanttemperatures (15°, 20°, 25° and 30°C) on two prey, Aphis fabae and Dysaphis crataegi, inlaboratory conditions. Total developmental time of the predator at 15°C and 30°C was shorter onD. crataegi (76.7 and 16.6 days, respectively) than on A. fabae (90.2 and 18.3 days respectively) butdid not differ significantly between the species at 20°C (36.8-38.9 days) or 25°C (24.0-24.9 days).The thermal constant (K) of development of H. axyridis from egg to adult was 258.2 day-degreesabove a lower developmental threshold of 11.2°C, on A. fabae, and 243.6 day-degrees above alower developmental threshold of 10.8°C, on D. crataegi.