Prey preference of Oenopia conglobata and the effect of previous feeding on consumption rate of the adult predator on pistachio psylla

Oenopia conglobata is an important active predator of pistachio psyllid in pistachio orchards. Alternative host or prey has an important role in the stability of natural enemies population in nature. In this study, prey preference of 4th larval instar, male and female of O. conglobata were examined in 10 replications. Nymphs and adults of Agonoscena pistaciae, Aphis fabae, Aphis gossypii and eggs of Ephestia kuehniella with corn pollen were used as preys. In order to study the effects of these preys on consumption rate of adult stage of O. conglobata when feeding only on the common pistachio psylla, it was reared on each diet separately and the feeding percentage was determined after 24 hours. The results showed that the larvae and adults of this predator prefer nymphs of pistachio psylla to other preys. They fed 87±1.52 and 85.5± 1.74 % of psyllid nymphs, respectively. The Manly preference index in the prey-preference test on different diets also showed more preference to nymphs of pistachio psylla compared to other diets. Those predators reared on psylla had more consumption rate on pistachio psylla nymphs (99.2±0.512 %) than to other preys. The results showed that O. conglobata preferred common pistachio psylla to other preys and the common pistachio psylla is a suitable prey for rearing of this predator, but due to feasibility and rearing expenses, A. fabae as a second prey is the most favourable prey for rearing of O. conglobata for biological control of A. pistaciae.