Percentage parasitism, adult longevity and daily parasitism of the parasitoid wasp, Encarsia berlesei on white peach scale Pseudaulacaspis pentagona, and its functional response to second instars of the scale insect

The Mulberry white scale, Pseudaulacaspis pentagona (Targ.-Tozz.) is a polyphagous pest with a wide range of hosts and is one of the most important pests of mulberry trees in Northern provinces of Iran. It is said to be one of the restricting factor in commercial sericulture. In the present study, efficacy of the specialist parasitoid wasp of this pest, Encarsia berlesei, was investigated under three distinct experiments: (1) percentage parasitism on different developmental stages of the host (choice test vs no-choice test); (2) adult's longevity, daily and overall mean rate of parasitism; and (3) functional response to host density changes. In no-choice test, the average parasitism in the presence of first and second instars and adult female were 0.0%, 11.02% and 3.84%, respectively. In choice test, the mean parasitism in the presence of second instars and adult females were as 10.26% and 2%, respectively. Mean longevity of adults in the presence and absence of the host were 4 and 10 days, respectively. The egg laying had an ascending order in early period and a descending order in the late period of adult stage. Overall, the mean parasitism was 28.4 hosts per female parasitoid. The wasp parasitism rate followed a type III functional response. The searching efficiency was 0.0003 ± 0.000057h-1 and the handling time was 3.695 ± 0.520 h. According to the results, especially considering the adult parasitoid longevity, it seems that E. berlesei is an efficient natural enemy for biological control of the Mulberry white scale.