Morphological traits are useful to investigate insect sex-related differences in body size and to reveal differences in resource use. It has been suggested that as the resource increases, so does the body size of organisms interacting with the resource, highlighting the crucial role of resource quality and quantity in determining the morphological traits of organisms interacting with the resource. Here, we describe morphological traits of two species of Bruchinae, Merobruchus terani (Kingsolver 1980) and Stator maculatopygus (Pic 1930), consuming seeds of Senegalia tenuifolia (Fabaceae: Mimosoideae). We evaluated the influence of monthly sample and sampling sites on tibia and femur length and biomass. In addition, we tested two predictions in which body size related to resource amount and body size related to longevity. Males of M. terani were heavier than females, whereas the two sexes of S. maculatopygus did not differ in biomass. Both species had larger body sizes in the late ripe-fruit stage. With respect to sampling sites, biomass of M. terani did not differ, whereas S. maculatopygus did differ in biomass. Merobruchus terani showed a positive relationship with seed traits, whereas S. maculatopygus showed no relationship. At the same time, fruit traits showed a negative effect on morphological traits for both beetle species. The longevity experiment, performed using only M. terani, showed an equal longevity and seed consumption rate for both sexes. Our study indicates that different species, interacting in the same system and performing similar functional behaviors, respond differently to the same resource.
Body size tibia length seed traits Merobruchus teraniStator maculatopygusSenegalia tenuifolia
This is a preview of subscription content, log in to check access.
We thank Ribeiro-Costa, C.S. for beetle identification and França, F.M. for the comments on the manuscript. We also thank the anonymous referees for their valuable comments on this study. Faria, L.D.B. thanks the Minas Gerais Research Foundation (FAPEMIG) and the Brazilian National Council for Scientific and Technological Development (CNPq) for financial support. Maia, L.F. and Tuller, J. thank the Brazilian Coordination for the Improvement of Higher Education Personnel (CAPES) for providing the scholarships.
Amarillo-Suárez AR, Stillwell RC, Fox CW (2011) Natural selection on body size is mediated by multiple interacting factors: a comparison of beetle populations varying naturally and experimentally in body size. Ecol Evol 1:1–14. doi:10.1002/ece3.1CrossRefPubMedPubMedCentralGoogle Scholar
Janzen ADH (1980) Specificity of seed-attacking beetles in a Costa Rican deciduous forest. J Ecol 68:929–952CrossRefGoogle Scholar
Johnson CD, Kingsolver JM (1976) Systematics of stator of North and Central America (Coleoptera: Bruchidae). US Dep Agric Tech Bull 1537:1–101Google Scholar
Johnson CD, Siemens HD (1997) Oviposition behaviour, guilds, host relationships and new host and distribution records for the genus Merobruchus Bridwell (Coleoptera: Bruchidae). Coleopts Bull 51(1):13–12Google Scholar
Kingsolver JG, Huey RB (2008) Size, temperature, and fitness: three rules. Evol Ecol Res 10:251–268Google Scholar
Kingsolver JG, John M (2004) Handbook of the Bruchidae of the United States and Canada (Insecta, Coleoptera). US Dep Agric Tech Bull 1912(2):1–636Google Scholar
Queiroz LP (2009) Leguminosas da Caatinga. Universidade Estadual de Feira de Santana, Feira de Santana, BrazilGoogle Scholar
R Development Core Team (2011) R: a language and environment for statistical computing. Ver 2.14.0. R Foundation for Statistical Computing, Vienna, Available from: http://www.rproject.orgGoogle Scholar
Savalli UM, Fox CW (1998) Sexual selection and the fitness consequences of male body size in the seed beetle Stator limbatus. Anim Behav 55:473–483CrossRefPubMedGoogle Scholar
Scriber JM, Slansky JF (1981) The nutritional ecology of immature insects. Annu Rev Entomol 26:183–211CrossRefGoogle Scholar
Shine R (1987) The evolution of large body size in females: a critique of Darwin’s “fecundity advantage” model. Am Nat 131(1):124–131CrossRefGoogle Scholar
Silva EF, Santos TRR, Fernandes-Bulhão C (2007) Levantamento florístico das lianas lenhosas, arbustos e subarbustos do Cerrado do Parque do Bacaba, Nova Xavantina-MT. Rev Bras Biociênc 5(2):948–950Google Scholar