Effects Of Temperature, Photoperiod And Food Stresses On The Development And Fecundity Of Ophraella Communa LeSage (Coleoptera: Chrysomelidae)

Ophraella communa Lesage (Coleoptera:Chrysomelidae) is an important and specific natural enemy against invasive weed, common ragweed(Ambrosia artemisiifolia). In order to understand the ability to resist enviorment stress, then develop several appropriate protective measures and provide better theoretical foundation for controlling the Ambrosia artemisiifolia L. by using Ophraella communa Lesage, low temperature stress, high temperature stress, photoperiod and food stress on the development and fecundity of this leaf beetle were studied in this paper. The main results were as follows:1. Effects of short-term low temperature stress on the development and fecundity of Ophraella communa LeSage (Coleoptera:Chrysomelidae)The hatch rate of eggs and the survival of larve decreased with the decreasing temperature.However, the survival rates of pupae did not differ from that of the control (P>0.05). The longevity and fecundity of adults decreased significantly and the survival rate of adult was also significantly affected under low temperature stresses, and the adult's survival rate decreased significantly along with the decreasing temperature.2. Effects of short-term high temperature stress on the development and fecundity of Ophraella communa LeSage (Coleoptera:Chrysomelidae)The hatch rate of eggs, the survival of larve and pupa, the survival rate and the longevity and fecundity of adults decreased with the increasing temperature. After 35—47℃short-term stresses,the duration of egg, larva and pupa were also shortened.3. Effects of photoperiod and food stresses on the development and fecundity of Ophraella communa LeSage (Coleoptera:Chrysomelidae)Under the same food condition, the survival of larve and pupa, the fucundity of adult and the hatching rate of F1 progeny of O. communa decreased with shortening illumination time, and the duration of larve, pupa and egg of F1 progeny of O. communa extented with shortening illumination time, but photoperiod had little effect on adult's longevity and sex ratio. Under the same photoperiod condition, effects of food stress on the development and fecundity of O. communa were significant. However, photoperiod and food stresses only have coupling effects on fucundity of adult and the development of Fi progeny of O. communa.