Multiple matings affect the reproductive performance of the aphidophagous ladybird beetle, Coelophora saucia (Coleoptera: Coccinellidae)

Omkar Omkar,Geetanjali Mishra,Satyendra K Singh

doi:10.14411/eje.2010.023

Abstract

The effect of multiple matings on the readiness with which mating occurred, fecundity, egg viability and adult longevity in the aphidophagous ladybird beetle, Coelophora saucia (Mulsant) (Coleoptera: Coccinellidae), was investigated under laboratory conditions. The time to onset of mating after previous pairing was found to decrease with increase in the number of matings. Multiply mated females had a higher fecundity and egg viability than single mated females. The trends in the results were analyzed using both binomial regression and the Gompertz equation. The best fitting curve was that based on the binomial equation, which indicates that 95% of the maximum theoretical fecundity was attained after mating 11 times and 95% of the maximum theoretical egg viability after mating 3 times. Unlike previous studies on ladybirds, a slight but statistically significant increase in female longevity was observed with increase in number of matings indicating that the male ejaculate might provide a supply of nutrients.

Highlights

In most organisms mating is either monogamous or promiscuous
The present study aims to determine the number of matings for optimal reproductive performance in both sexes of the aphidophagous ladybird, Coelophora saucia, which is an important natural enemy of aphids and mealybugs infesting various economically important agricultural, horticultural and ornamental crops (Dai, 1990; Pathak, 2008)
The results reveal that multiple matings decrease the time to the start of mating, and increase fecundity and egg viability in C. saucia

Summary

Introduction

In most organisms mating is either monogamous or promiscuous. Multiple mating with more than one male within a single breeding season is reported for a number of insects (Olsson et al, 1994; Eberhard, 1996; Zeh, 1997). Multiple matings help females to accrue direct material benefits such as an adequate supply of sperm (Drnevich et al, 2001), defensive chemicals (González et al, 1999), nutrients and/or oviposition stimulants (Wagner et al, 2001). It is associated with a number of costs, such as, loss of time and energy, risk of predation and infection by sexually transmitted diseases (Daly, 1978; Martens & Rehfeldt, 1989; Hurst et al, 1995; Blanckenhorn et al, 2002).

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Results

Conclusion