Acta Entomologica Sinica ›› 2017, Vol. 60 ›› Issue (1): 60-66.doi: 10.16380/j.kcxb.2017.01.008

• RESEARCH PAPERS • Previous Articles     Next Articles

Geographical variation of life-history traits in the cabbage beetle,Colaphellus bowringi (Coleoptera: Chrysomelidae)

ZOU Chao1, XIAO Liang2, HE Hai-Min1, ZENG Yi1, XUE Fang-Sen1,*   

  1. (1. Institute of Entomology, Jiangxi Agricultural University, Nanchang 330045, China; 2. Agricultural Technology Extension Station of Songhu Town of Xinjian District, Xinjian, Jiangxi 330107, China)
  • Online:2017-01-20 Published:2017-01-20

Abstract: 【Aim】 Comparison of life-history traits among different geographical populations is one of the most effective methods for revealing how insects have evolved to adapt to their local environments. This study aims to understand how life history traits of the cabbagem beetle, Colaphellus bowringi vary with latitude. 【Methods】 The developmental time from egg hatching to pupation and from pupation to adult eclosion, and pupal and adult weight of six geographical populations of C. bowringi from different latitudes in China under constant temperature 19℃ and a photoperiod of 16L∶8D were examined in the laboratory. 【Results】 The larval duration increased gradually with increasing latitude, and the growth rate was negatively correlated with latitude, showing co-gradient variation in the two traits. However, the pupal duration was not significantly different among different geographical populations. Body weight decreased gradually with increasing latitude, showing a converse Bergmann cline. The sizes of female pupae and adults were significantly larger than those of males in all populations, showing female biased sexual size dimorphism (SSD). The SSD index varied with the latitude, with the highest value at middle latitude. Furthermore, male pupae lost significantly more weight at metamorphosis compared with females, so the SSD index was higher in the adult stage than in the pupal stage. 【Conclusion】 The results indicate that the larval duration, growth rate and body weight of C. bowringi vary significantly with latitude.

Key words: Colaphellus bowringi, latitude, developmental duration, growth rate, body weight, sexual size dimorphism (SSD)