Functional response of Oenopia conglobata contaminata (Coleoptera:Coccinellidae) to Agonoscena pistaciae (Hemiptera: Psyllidae) at two different temperatures

Abstract

Oenopia conglobata contaminata, is an important predator of the most important pistachio pest, Agonoscena pistaciae, in Iran. The functional response of the adult, third and fourth larval instars of O. conglobata contaminata fed on the common pistachio psylla, A. pistaciae, was studied at 22° and 25 °C (65 ± 5%RH and 16 L: 8D). Different psylla densities of 10, 20, 40, 80, and 160 were used. The data were fitted a type II functional response in all the stages. There was a significant difference in the attack rate and handling time of the predator in all stages at 22 °C and 25 °C. The maximum attack rate (T/Th) occurred at 25 °C. The lowest and highest attack rates were 0.046 and 0.154 for adult of the predator at 22 °C and 25 °C, respectively. The handling time decreased significantly as the temperature increased from 22 °C to 25 °C in all treatments. The results suggest that the efficiency of the Oenopia conglobata to control the pistachio psylla is high at 25 °C. On the other hand, the predatory beetle O. conglobata contaminata reacted to increasing temperature by enhanced search rate and activity.