橘小实蝇与番石榴实蝇卵及蛹的种间竞争

Interspecific competition between Bactrocera dorsalis and B. correcta( Diptera: Tephritidae) eggs and pupae

【背景】实蝇的竞争可能发生在生活史的各个阶段,但未见卵和蛹的种间竞争的相关报道。【方法】将橘小实蝇与番石榴实蝇的卵及蛹按照相应的比例或龄期分别进行混合培养,分析2种实蝇的卵或蛹混合后的发育历期和存活率是否受到彼此影响。【结果】橘小实蝇与番石榴实蝇的卵同龄等量混合,对彼此卵的历期和孵化率无影响。当橘小实蝇和番石榴实蝇的蛹为新鲜蛹时,分别与比它们蛹龄大1 d的对方蛹混合,蛹的羽化率分别为(87.67±3.61)%和(84.33±2.56)%,显著小于对照,说明在此混合蛹处理中,后化蛹者的发育可能受到先化蛹者的抑制。【结论与意义】总体上,在卵和蛹期,橘小实蝇与番石榴实蝇未产生竞争作用;但不排除蛹期竞争的可能性,这种竞争可能存在于特定的蛹期。

【Background】Interspecific competition in the family Tephritidae( fruit flies) can happen at every developmental stage of the life cycle. However,interspecific competition during egg and pupa stages of two fruit flies has not been observed.【Method】Bactrocera dorsalis and B. correcta were reared together under different proportions and time of introduction of the second species. The developmental duration and survival rate of the two species were then measured. 【Result】There were no effects on the duration of the egg stage and hatching rate of both species when eggs of B. dorsalis and B. correcta were initially mixed in equal numbers and at the same egg age. However,when pupae of different ages( one new and one of one day old) of the two fruit flies were mixed,emergence rates of the younger pupae were respectively( 87.67±3.61) % for B. dorsalis and( 84.33±2.56) % for B. correcta,which were significantly less than the respective controls. This outcome implied that the younger pupae could inhibit the growth by the older pupae. 【Conclusion and significance】The study shows that interspecific competitive effect between B. dorsalis and B. correcta is minimal with a possibility of competition at the pupal stage.