烟碱对槟榔红脉穗螟生长发育和存活的影响

【背景】红脉穗螟是槟榔上的重要害虫，近年来危害日愈严重。【方法】采用饲喂法、浸卵法研究了烟碱对红脉穗螟不同龄期幼虫的生物活性及对卵、幼虫、蛹发育和存活的影响。【结果】烟碱对红脉穗螟各龄幼虫均表现出生物活性，且随着龄期的增大，红脉穗螟幼虫对烟碱的敏感性呈现降低的趋势；烟碱对红脉穗螟5龄幼虫的L％、￡c。￡cq。分别为5．13、20．69、292．10mg·L-1，同时烟碱可延长幼虫和蛹的发育历期。经不同浓度烟碱处理后，卵的孵化率大大降低，且初孵幼虫存活率也受到影响，部分幼虫无法成功转至2龄；同一卵龄中，LC25和LC50。处理的卵孵化率无明显差异，且显著高于LC90处理组。不同浓度烟碱处理后的红脉穗螟化蛹率和羽化率均显著降低，其中以LC90处理组影响最大，化蛹率和羽化率仅为18．89％和15．56％，显著低于对照组。【结论与意义】烟碱作为一种重要的植物源杀虫剂，对红脉穗螟的发育和存活均表现出生物活性，可作为该虫防治的备选药剂。

Effect of nicotine on the development and survival of Tirathaba rufivena Walker (Lepidoptera: Pyralididae)

[ Background ] Tirathaba rufivena Walker is one of the important lepidopteran pests in Areca catechu L., and its damage has increased recently. [ Method] In order to detect the effect of nicotine on the development and survival of T. rufivena, eggs were dipped, and larvae were fed with diet containing various concentrations of nicotine to describe the biological activity on eggs, larvae, pupae. [ Result ] Nicotine showed bioactivities against all laival instars of T. rufivena, but the sensitivity was gradually reduced during larval development. The LCz~, LCso and LCgo values for 5th instar larvae were 5.13 mg L1 , 20.69 mg Ll and 292.10 mg L1 , respectively; the development of larvae and pupae was delayed. Nicotine also reduced egg hatchability and the survival newly hatched larvae. Egg hatchability did not differ between treatments with LC25 and LC50 doses, but the LC90 treatment caused lower egg hatch. The pupation and emergence rates were also decreased; at LCgo, they were 18.89% and 15.56% , respectively, both signifi cantly lower than those in the control group. [ Conclusion and significance] As an important botanical pesticide, nicotine showed strong negative effects on the development and survival of T. rufivena, and may be used as reference in pesticide development.