Male behavioural plasticity depends on maternal mating status in the two-spotted spider mite

Keiko Oku,Tom P G Van Den Beuken

doi:10.1007/s10493-017-0127-9

Abstract

In haplodiploid organisms including the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), both unmated and mated females can produce male offspring. A previous study reported that males produced by unmated females (UM males) find pre-reproductive females more quickly than males produced by mated females (M males) in T. urticae. However, it remains unclear what factors cause the difference. We investigated effects of maternal mating status on mate-searching behaviour of their sons by changing the sons’ developmental environment. In T. urticae, the primary sex ratio of mated-female colonies is female-biased. For both UM and M males, half of individuals were reared with males to imitate unmated-female colonies, whereas the rest were reared with females to imitate mated-female colonies. In UM males, individuals that had developed with males found pre-reproductive females more quickly than those that had developed with females. However, such a difference was not observed in M males. This indicates that behavioural response to the developmental environment differs between UM and M males. It means that the behavioural plasticity depends on maternal mating status. When males were individually reared, however, there was no significant difference in the mate-searching behaviour between UM and M males, indicating that maternal mating status does not independently affect their sons’ mate-searching behaviour. This study showed that male mate-searching behaviour is changed by their developmental environment and maternal mating status. This behavioural plasticity depending on maternal mating status is the first reported in haplodiploid organisms.

Highlights

Phenotypes of organisms, such as behavioural and morphological traits, are plastic
A previous study reported that males produced by unmated females (UM males) find pre-reproductive females more quickly than males produced by mated females (M males) in T. urticae
A strain of T. urticae without red eyespots was established from one non-eyespot male (Fig. 1), which was accidentally found in the stock cultures, as follows: the non-eyespot male was allowed to mate with 20 unmated females arbitrarily selected from the stock cultures

Summary

Introduction

Phenotypes of organisms, such as behavioural and morphological traits, are plastic. A single genotype may produce different phenotypes in response to environmental conditions (West-Eberhard 1989). In order to determine what factors cause a phenotypic trait of organisms, it is important to consider effects within one generation and between generations In haplodiploid organisms such as the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), haploid males develop from unfertilized eggs and diploid females develop from fertilized eggs (e.g., Helle and Bolland 1967; Heimpel and de Boer 2008). There are only two papers reporting effects of maternal mating status on male-offspring behaviour (the spider mite T. urticae: Ohzora and Yano 2008; the beetle Coccotrypes dactyliperda: Gottlieb et al 2014). If developmental environment determines male behaviour regardless of the mating status of their mothers, males that developed in colonies established by unmated females are expected to find females more. We report male behavioural plasticity depending on maternal mating status in combination with developmental environment

Materials and methods

Results and discussion

Compliance with ethical standards