›› 2018, Vol. 61 ›› Issue (6): 704-711.doi: 10.16380/j.kcxb.2018.06.009

• 研究论文 • 上一篇    下一篇

捕食性瓢虫的体型大小影响其偏好捕食防御性强的猎物吗?(英文)

Priya PATEL, Bhupendra KUMAR*, Dinesh KUMAR    

  1. (Department of Zoology, Banaras Hindu University, Varanasi-221005, Uttar Pradesh, India)
  • 出版日期:2018-06-20 发布日期:2018-06-20

Does body size of coccinellid predators (Coleoptera: Coccinellidae) influence their preference to eat well-defended prey? (In English)

Priya PATEL, Bhupendra KUMAR*, Dinesh KUMAR   

  1. (Department of Zoology, Banaras Hindu University, Varanasi221005, Uttar Pradesh, India)
  • Online:2018-06-20 Published:2018-06-20

摘要: 【目的】尽管瓢虫表现出种间和种内特异性体型大小的变异,但是瓢虫体型大小的变异是否会改变其选择捕食防御性强(即表现出各种防御反应,包括积极躲避捕食、挣脱捕食者或频繁利用防御性化学物质)的猎物,这一问题尚不清楚。本研究中,我们假设不论体型大小,捕食性瓢虫七星瓢虫Coccinella septempunctata (L.)和六斑月瓢虫Menochilus sexmaculatus (Fab.)都将增加其对猎物萝卜蚜Lipaphis erysimi (Kaltenbach)的捕食,只要猎物处于防御性强的龄期,原因是处于防御性强的龄期的猎物体型大且更有活力。【方法】我们将萝卜蚜4龄若虫期作为防御性强的龄期,将2龄若虫期作为防御性弱的龄期,评价七星瓢虫和六斑月瓢虫这两种瓢虫的大型和小型变异体对萝卜蚜的偏好性。【结果】结果表明,六斑月瓢虫的大型和小型雌性变异体更多地捕食防御性弱的萝卜蚜,而七星瓢虫的大型和小型雌性变异体分别对防御性强和防御性弱的萝卜蚜捕食较多。在混合饲料上,七星瓢虫雌性变异体对两类蚜虫的捕食百分比相似,而六斑月瓢虫变异体对防御性弱的萝卜蚜的捕食百分比较高。尽管随着七星瓢虫雌虫体型的增大而对两类猎物的捕食增多,但随着六斑月瓢虫雌虫体型的增大,只对防御性强的蚜虫的捕食量增加。【结论】本研究结果与我们的假设相反,并证明了:(1)小型瓢虫更多地只是捕食防御性弱的猎物,而大型瓢虫选择性地捕食防御性强的猎物;(2)在瓢虫种内和种间,随着捕食者体型的增大,对防御性强的猎物的偏好性增加。可将这些结果用于瓢虫的室内大规模饲养,以提高对萝卜蚜的生物防治。

关键词: 七星瓢虫, 六斑月瓢虫, 萝卜蚜, 瓢虫, 蚜虫, 生物防治, 警戒信号

Abstract: 【Aim】 Despite the fact that coccinellids display inter- and intra-specific size variations, the question of whether size variations in coccinellid species modify their choice to eat well-defended prey (i.e., displaying various defence responses, including actively evading capture, fighting off predators or frequently using defensive chemicals) is still unclear. In present study, we hypothesized that irrespective of their size the coccinellid predators, i.e., Coccinella septempunctata (L.) (C7) and Menochilus sexmaculatus (Fab.) (Ms), would increase their consumption of a prey type [i.e., the mustard aphid, Lipaphis erysimi (Kaltenbach)] only when prey instars would be well-defended. This is because well-defended prey instars are large and more energetic. 【Methods】 We therefore, categorized the 4th nymphal instar of L. erysimi as well-defended and the 2nd nymphal instar as poorly-defended and assessed their preference by large and small variants of the two coccinellid species. 【Results】 The results revealed higher consumption of poorly-defended instar nymphs by both female variants of Ms, while large and small females of C7 consumed higher percentage of well-defended and poorly-defended instar nymphs, respectively, on an exclusive diet of well-defended/poorly-defended prey. On a mixed diet, female variants of C7 consumed similar fraction of both the prey instar nymphs, while variants of Ms consumed higher fraction of poorly-defended instar nymphs. While consumption of both prey instar nymphs increased with the increase in size of C7 females, but consumption of only well-defended instar nymphs increased with the increase in size of Ms females. 【Conclusion】 The results therefore oppose our hypothesis and illustrate that: (i) small coccinellids are more confined to poorly-defended prey instar nymphs while large coccinellids selectively consume well-defended prey instar nymphs; and (ii) within and between coccinellid species, preference for well-defended prey instars increases with the increase in size of predators. Results may be utilized for mass rearing of these coccinellids in laboratories for augmentative biocontrol of mustard aphids.

Key words: Coccinella septempunctata, Menochilus sexmaculatus, Lipaphis erysimi, coccinellids, aphids, biological control, aposematic signals