The predatory bug, Anthocoris minki Dohrn (Hem.: Anthocoridae), is an important predator of ash psyllid, Psyllopsis repens Loginova (Hem.: Psyllidae) and is very abundant on ash trees (Fraxinus excelsior L.) in Mashhad region, Iran. Functional response parameters, handling time and searching efficiency are of particular value in understanding feeding behavior of a predator. The type of the functional response and the rates of its parameters are influenced by different factors. In this study, the functional responses of A. minki to densities of P. repense at different temperatures (15, 24 and 30 °C), prey instar (2nd and 4th instar nymphs), developmental stage of predator (4th nymph and adult) and sex of predator (male and female) were investigated. The effects of predator densities and interference on searching efficiency were estimated. Logistic regression and nonlinear least- square regression were used to estimate the type of the functional response and its parameters, respectively. In order to determine the per capita searching efficiency and interference coefficient, Nicholson’s model and linear regression were used. The results showed a type II functional response on all experiments except of adult predators to 2nd instar nymphs of prey which exhibited a type III functional response. The greatest value of attack rate and the shortest handling time were seen at 30 °C. The per capita searching efficiency decreased as densities increased but there was no significant difference. The laboratory results suggest that A. minki has potential to control P. repens on ash trees but further research is needed under field conditions.

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