长期饲喂不同类型椰子叶片对椰心叶甲生长发育的影响

Effects of feeding Brontispa longissima coconut leaves at different growth stages on the growth and development of this pest

【目的】研究不同生长阶段的椰子叶片对椰心叶甲Brontispa longissima Gestro生长发育的影响。【方法】选用椰子心叶、椰子半展叶和椰子全展叶长期饲养椰心叶甲,并比较驯化后椰心叶甲种群的发育历期、繁殖力和种群趋势指数的差异。【结果】用椰子心叶和椰子全展叶长期饲养的椰心叶甲种群在卵长度(P=0.005<0.01)和蛹重上差异显著(P<0.01)。从整个幼虫发育历期来看,椰子心叶、椰子半展叶和椰子全展叶驯化种群的幼虫发育历期分别为41.45、40.61和36.38 d,椰子全展叶驯化种群的幼虫发育历期最短;椰子心叶驯化种群的交配产卵前期显著短于椰子半展叶和椰子全展叶驯化种群(P<0.05);椰子半展叶驯化种群的平均产卵量最多,为161.78粒,其次是椰子全展叶种群的147.33粒,最少的是椰子心叶驯化种群,其平均产卵量为112.60粒。用椰子心叶、椰子半展叶和椰子全展叶长期驯化种群的的种群趋势指数分别是24.79、35.86和45.94。【结论】长期饲喂不同生长阶段的椰子叶片对椰心叶甲的生长发育有显著性影响,其中椰子全展叶驯化种群的发育历期最短,存活率最高,种群趋势指数最高。椰子全展叶是最适合椰心叶甲的生长发育的叶片。

[Objectives]To investigate the effects of feeding Brontispa longissima coconut leaves at three different growth stages on their growth and development.[Methods]Groups of B.longissima were fed either unopened coconut fronds,half-opened fronds or opened fronds,and differences in their developmental duration,fecundity and population trend index were measured and compared.[Results]There were significant differences in egg length and pupal weight between B.longissima that were fed unopened fronds compared to those fed opened fronds.Larval development periods were 41.45 d for B.longissima fed unopened fronds,40.61 d for those fed half-opened fronds and 36.38 d for those fed opened fronds.The pre-oviposition period of B.longissima fed on unopened fronds was significantly shorter than that of those fed half-opened fronds or unopened fronds.The highest average fecundity(161.78)was recorded in B.longissima fed half-opened fronds,the second highest(147.33)in those fed opened fronds and the lowest(112.60)in those fed unopened fronds.The population trend index of B.longissima fed unopened fronds,half-opened fronds or opened fronds was 24.79,35.86 and 45.94,respectively.[Conclusion]The growth stage of coconut leaves provided to B.longissima had a significant effect on the growth and development of this species.B.longissima fed opened fronds had the shortest developmental period,the highest survival rate and the highest population trend index.Opened coconut fronds are a more suitable food than unopened or half-opened fronds for B.longissima.