Allocation by Female Parasitoid Trissolcus vassilievi (Mayr) Encountering with Sunn Pest Eggs (Eurygaster integriceps Puton)

Several studies showed that increasing the total available time for parasitoid causes biases in parameter estimation of functional response experiments. Hence direct observations are required for unbias estimating of handling time. In addition there is some difference among geographical populations of parasitoid. Therefore in this study, two populations of Trissolcus vassilievi (Mayr), (Tabriz and Varamin) were chosen and time allocated for different activities were recorded by direct observations. The time budget of a female parasitoid (24h-old fertile females of the 3rd generation) was divided to four components including drumming, parasitism, host marking and performing actions and duration of each behavior was recorded for three hours in an experimental arena.Time spent for whole clutch was 1071±70.25, 4288.6±293.26, 874.2±60.38 and 972.0±133.89 seconds in Tabriz wasps and 1237.2±94.03, 4911.6±365.72, 935±87.08 and 1136.8±69.20 seconds in Varamin wasps, for above respect of behaviors. Furthermore, per capita times assigned for above behaviors were 31.87±1.16, 127.64±2.18, 26.02±0.83 and 28.93±6.75 seconds for Tabriz wasps and 31.40±0.83, 124.66±1.88, 23.73±0.77 and 28.85±6.05 seconds for Varamin wasps respectively. Handling time increased slowly until the end of the experiment. It was concluded that the classical functional response experiments should be accompanied by direct recording of insect behavior and parasitoids/predators should be allowed to determine the patch time themselves in a host arena. Otherwise, handling time will be overestimated due to time wasted by predator/parasitoid during satiation or depletion of egg reservoires.