Revista Brasileira de Entomologia Revista Brasileira de Entomologia
Rev Bras Entomol 2017;61:243-7 - Vol. 61 Núm.3 DOI: 10.1016/j.rbe.2017.04.003
Biology, Ecology and Diversity
Morphological traits, allometric relationship and competition of two seed-feeding species of beetles in infested pods
Jessica A. Silva, Angelo B. Monteiro, Laís F. Maia, Lucas D.B. Faria,
Universidade Federal de Lavras, Departamento de Biologia, Setor de Ecologia e Conservação, Lavras, MG, Brazil
Recebido 02 Fevereiro 2017, Aceitaram 11 Abril 2017
Abstract

Pair-wise competition produces asymmetric consequences for the interacting species, resulting in reduction of species fitness at the individual scale; however, little is known of the effects of competition on the allometric patterns of insects. In this study, we explored how competition, by means of pod infestation, affects the development of female and male individuals in the co-occurring bruchine beetles Merobruchus terani and Stator maculatopygus. We found differences between M. terani and S. maculatopygus in all morphometric traits, but no significant differences between males and females in either species. We also found, with an increasing degree of pod infestation, a positive trend in the pronotum, elytron and body weight of M. terani and a negative trend in morphological traits and body weight of S. maculatopygus. A negative allometry was maintained, suggesting that with increasing body weight, the body structures did not increase proportionally. On the other hand, we found that increasing the degree of pod infestation produced a wider variation in the individuals’ body size than in low levels of infestation. Finally, we discuss how pod infestation can trigger competition between species, with both positive and negative impacts, even though the species function similarly in resource exploitation.

Keywords
Merobruchus terani, Stator maculatopygus, Senegalia tenuifolia, Bruchinae, Negative allometry
Rev Bras Entomol 2017;61:243-7 - Vol. 61 Núm.3 DOI: 10.1016/j.rbe.2017.04.003