Abstract
Pair formation in the lesser wax moth, Achroia grisella (Lepidoptera: Pyralidae), is initiated by male ultrasonic signals that attract receptive females. Individual males vary in attractiveness to females, and the most attractive males are distinguished by exaggeration of three signal characters: pulse rate, peak amplitude and asynchrony interval (temporal separation between pulses generated by movements of the left and right wings during a given wing upstroke or downstroke). Using flow-through respirometry, we measured the resting and signalling metabolic rates of males whose relative attractiveness was known. Acoustic recordings and metabolic measurements were made simultaneously, and we calculated net metabolic rates and factorial metabolic scopes as measures for the energetic cost of signalling. On average, attractive males had higher net metabolic rates and factorial metabolic scopes than unattractive ones, but many unattractive males also had high values. Thus, high expenditure of energy on signalling is necessary but not sufficient for attractiveness. This may result because only one of the three signal characters critical for female preference, pulse rate, is correlated with energy expenditure. Although the results are consistent with the good genes model of sexual selection, they do not conflict with other indirect or direct mechanisms of female choice.
| Original language | English |
|---|---|
| Pages (from-to) | 905-913 |
| Number of pages | 9 |
| Journal | Animal Behaviour |
| Volume | 55 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 1998 |
Bibliographical note
Funding Information:We are grateful to Robert Minckley for collecting wax moths, to T. Ohno for constructing the respirometric chamber, to Ken Hampton for advice on operating the infra-red CO2 analyzer, and to Craig Martin for flowmeter calibration. The assistance of Jamie McCullough, Nathan Orr and Feng-You Jia with insect rearing, attractiveness evaluation and signal recording was indispensable. Tom Peters and Rick Roggero, both of the University of Kansas Instrumentation Development Laboratory, developed custom computer software for ultrasonic signal acquisition and analysis. The manuscript benefited greatly from reviews by Bob Collins, Klaus-Gerhard Heller, Andy Snedden, Ken Prestwich and several anonymous referees. This work was funded by U.S. National Science Foundation grant IBN 9407162 to M.G. and DFG grant RE 1167/1-1 to K.R.