EFFECTS OF DIFLUBENZURON ON LONGEVITY AND REPRODUCTION OF RIPTORTUS-CLAVATUS (HEMIPTERA, ALYDIDAE)

Laboratory studies were done to determine the effects of diflubenzuron on the longevity and reproduction of adult bean bugs, Riptortus clavatus (Thunberg). Irrespective of adult age at the time of topical application, the number of eggs laid per female was decreased to 0-26.1% of the untreated controls by treatment with 1.0-mu-g of diflubenzuron and to 7.6-58.3% by treatment with 0.01-mu-g. Treatment of adults within 3 h of emergence significantly reduced not only adult longevity and the number of eggs laid per female but also adversely affected the period before oviposition and ovarian development. When newly emerged adults were treated with higher dosages of diflubenzuron, considerable adverse effects were apparent. We concluded that significant reduction in egg production by adults treated with diflubenzuron may be caused by the inhibition of ovarian development of the adult bugs.