زيستشناسي و تغييرات جمعيت كفشدوزك SCYMNUS SYRIACUS MARSEUL در استان گيلان

Studies on biology of Scymnus syriacus Marseul (Col: Coccinellidae) in Gilan province.

Biology of the predatory ladybeetle Scymnus syriacus was studied at 25? C , %65 ± 5 RH , and 16L: 8D in laboratory. Population fluctuation was also studied during 1995-1996 in Rasht area. The coccinellid has four instar larvae and one prepupa and one pupa.Its developmental time from egg to adult takes 22.7 days under studied condition. Females longevity is shorter than males. Mean number of eggs laid per day and realized fecundity of females are 15.8 and 597.5, respectively. The rate of daily oviposition decrease as the female age. S.syriacus pass the Winter as adult stage under fallen leaves and other plant debris . In the middle of Spring they become active and their reproduction continue until mid Autumn. Adults and larvae feed on aphids , especially citrus green aphid, Aphis spiraecola. The predator had six generations in a year in Rasht area.