Caste and wing loading in a social wasp (Hymenoptera, Vespidae, Dolichovespula maculata)

Christopher K Starr,Robert S Jacobson,Joan W Krispyn,Joshua A Spiers

doi:10.3897/jhr.84.68800

Abstract

Variation in wing design and wing loading according to body weight is well studied across taxa of birds and flying insects. Comparable studies have not been made in the few insects that show substantial size variation within the same phenon of a single species. We examine body measures of adults of the social waspDolichovespula maculata(Linnaeus, 1763), with particular attention to the limbs and wing loading. As expected, measures of the length of the legs scales isometrically with overall body weight and size. Against expectation, wing size also scales isometrically with body weight and size. This does not match the general pattern of comparison across species of flying animals, in which larger individuals have relatively larger wings, as a partial compensation for greater wing loading. We suggest that wing size inD. maculatamay be constrained by the demands of life in a crowded nest.

Highlights

Ever since Thompson’s (1917) classic study, it has been understood that body form varies with overall body size in meaningful ways
Dry weight is the preferred index of overall body weight, as smaller individuals may have lost more water than large individuals during the months frozen despite the sealed containers
With forewing length as a linear measure of relative wing area, our results indicate a marked increase in wing loading with increased body size (Fig. 7)

Summary

Introduction

Ever since Thompson’s (1917) classic study, it has been understood that body form varies with overall body size in meaningful ways. The several interspecific studies of bees and other insects give results consistent with this pattern (Byrne 1988; Danforth 1989; Dyer 1991; Bullock 1999; Dudley 2000; Davreau et al 2005) As another well established rule in birds, larger species tend to have higher aspect ratio, the ratio of wing length to width, so that their wings are relatively narrower (Warham 1977; Pennycuick 1987, 2008; Alexander 2002). One might reasonably expect to find within the same relationships within a given species, i.e. a) a compromise between constant body size and constant wing loading, and b) greater aspect ratio in larger individuals. We predicted that leg length will increase isometrically with a linear measure of body size in D. maculata

Methods

Results

Conclusion