Intraspecific competition in Zabrotes subfasciatus： Physiological and behavioral adaptations to different amounts of host  

作　　者：Isabel R.V.Teixeira Fernando S.Zucoloto 

机构地区：[1]Insect Nutrition and Feeding Behavior Laboratory,Department of Biology,Faculdade de Filosofia Ciencias e Letras de Ribeirao Preto Universidade de Sao Paulo,Sao Paulo [2]epartment of Biology,Federal Institute of Sul de Minas-Campus Muzambinho,IFSULDEMINAS Muzambinho,Minas Gerais,Brazil

出　　处：《Insect Science》2012年第1期102-111,共10页昆虫科学（英文版）

摘　　要：The effects of competition on populations of the bean weevil Zabrotes sub- fasciatus were analyzed during 41 generations under different competition levels. Three competition environments were established by maintaining the number of couples （6） and varying the amount of available host seeds： HC, high （limited availability of host： 1.35 g）; IC, intermediate （intermediate availability of host： 6 g）; and LC, low competition （abun- dance of host： 36 g）. It was found that the distribution of the eggs laid on grains was different among treatments： in LC, for example, although females showed high fecundity （35.4 ± 5.6 eggs/female） the number of eggs laid on each grain was small （1.2 ± 0.4 eggs on each seed）, thus avoiding larval competition of their offspring; whereas in HC treatment, females showed low fecundity （27.04 ± 4.5 eggs/female） but laid many eggs on each grain （15.03 ± 4.3 eggs）. There were no changes in the ability to respond to different amounts of host via oviposition behavior （egg distribution） during 41 generations. How- ever, HC females had more offspring than LC females under HC conditions. This suggests that HC insects evolved toward higher fitness in crowded conditions. In addition, after inverting the competition level, insects behaved independently of the treatment conditions they experienced through generations, thus showing that oviposition behavior is flexible. Taken together, our results show that Z. subfasciatus presents a broad range of behavioral and physiological responses which allows for quick and reversible adjustments to sudden changes in the amount of resources.The effects of competition on populations of the bean weevil Zabrotes sub- fasciatus were analyzed during 41 generations under different competition levels. Three competition environments were established by maintaining the number of couples （6） and varying the amount of available host seeds： HC, high （limited availability of host： 1.35 g）; IC, intermediate （intermediate availability of host： 6 g）; and LC, low competition （abun- dance of host： 36 g）. It was found that the distribution of the eggs laid on grains was different among treatments： in LC, for example, although females showed high fecundity （35.4 ± 5.6 eggs/female） the number of eggs laid on each grain was small （1.2 ± 0.4 eggs on each seed）, thus avoiding larval competition of their offspring; whereas in HC treatment, females showed low fecundity （27.04 ± 4.5 eggs/female） but laid many eggs on each grain （15.03 ± 4.3 eggs）. There were no changes in the ability to respond to different amounts of host via oviposition behavior （egg distribution） during 41 generations. How- ever, HC females had more offspring than LC females under HC conditions. This suggests that HC insects evolved toward higher fitness in crowded conditions. In addition, after inverting the competition level, insects behaved independently of the treatment conditions they experienced through generations, thus showing that oviposition behavior is flexible. Taken together, our results show that Z. subfasciatus presents a broad range of behavioral and physiological responses which allows for quick and reversible adjustments to sudden changes in the amount of resources.

关 键 词：bean weevil COLEOPTERA egg distribution OVIPOSITION Phaseolus vulgaris phenotypic plasticity 

分 类 号：S642.2[农业科学—蔬菜学] Q948.122.1[农业科学—园艺学]