Does seed size mediate sex-specific reproduction costs in the Callosobruchus maculatus bean beetle?

Dariusz Krzysztof Małek,Maciej Jan Dańko,Marcin Czarnoleski,Nicolas Chaline

doi:10.1371/journal.pone.0225967

Dariusz Krzysztof Małek, Maciej Jan Dańko + Show 2 more

Open Access

https://doi.org/10.1371/journal.pone.0225967

Copy DOI

Abstract

There is a trade-off between reproductive effort and adult longevity, and when resource allocation is taken into account, it is especially pronounced in species that have aphagous adult forms. This trade-off may be further complicated by environmental factors such as nutrient availability during larval development and by the other sex, which influences the costs of reproduction due to the presentation of nuptial gifts. Here, we examined the influence of larval nutrient quantity on the sex-specific longevity costs of reproduction in the gift-giving seed beetle Callosobruchus maculatus. We found no indication that differences in the nutrient quality of larger and smaller host seeds influence survival in virgin and reproducing individuals or nuptial gift size in reproducing individuals. However, in the case of reproducing individuals, the effect of seed size on survival was statistically marginal. Therefore, we advise taking this into account when investigating reproductive efforts in this species. We have also observed interesting interactions between male and female reproductive costs. While females had generally higher mortality than males, nuptial gifts resulted in lowered female mortality and increased male mortality. Additionally, we found a possibly non-linear relationship between nuptial gift size and the offspring production rate of female recipients.

Highlights

The costs of parental investment to current offspring production negatively affect growth, future reproductive capacity, and lifespan [1,2,3]
C. maculatus beetles developed in bean seeds that varied in mass from 119 to 310 mg, so some larvae had an almost three times larger supply of resources for development (Fig 2A)
We did not find evidence that this variance in seed size was related to detectable differences in adult size (Fig 2A, Table 1A), longevity (Table 2), the size of the gifts produced by males (Fig 2B, Table 1B and 1C) or the reproductive performance of females (Table 4)

Summary

Introduction

The costs of parental investment to current offspring production negatively affect growth, future reproductive capacity, and lifespan [1,2,3]. Males and females incur different reproductive costs [7]. Such differences originate from differences in the investment in individual gametes [8], the total costs of gamete production may be similar for both sexes [9], and a reliable assessment of the ultimate reproductive costs should consider a range of sex-specific behaviours and physiological activities [8]. The reproductive costs of mating partners can influence one another, especially if mating involves the transfer of resources between partners.

Methods

Results

Conclusion