Neither Mating Rate Nor Spermatophore Feeding Influences Longevity in a Ladybird Beetle

Authors

  • Jennifer C. Perry,

    1.  Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
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  • Locke Rowe

    1.  Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
    2.  Centre for Biodiversity and Conservation Biology, Royal Ontario Museum, Toronto, ON, Canada
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Jennifer C. Perry, Department of Ecology and Evolutionary Biology, University of Toronto, 25 Harbord St., Toronto, ON M5S 3G5, Canada. E-mail: jperry@zoo.utoronto.ca

Abstract

Females of many species experience costs associated with mating. Seminal products, including nuptial gifts, may mitigate these mating costs or exacerbate them. For example, nuptial gifts derived from male accessory glands may transfer nutrition or potentially harmful seminal proteins to females. In this study, we assay the costs of multiple mating and the consumption of seminal products in a ladybird beetle. We compared longevity in females mated singly or multiply, while allowing or preventing spermatophore consumption at each mating. In order to distinguish a cost of mating per se from a cost of elevated reproduction, we prevented reproduction by using nutrient-stressed females. Mating singly or multiply had no effect on female longevity, nor did spermatophore feeding influence longevity. The results imply, first, that intermediate mating rates do not directly harm females, though females may experience other indirect costs of mating (e.g. reduced foraging efficiency) or costs of reproduction; and second, that spermatophores transfer neither food nor directly harmful substances to female ladybirds.

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