Rebel honeybee workers have a tendency to become intraspecific reproductive parasites.

Karolina Kuszewska,Michal Woyciechowski,Krzysztof Miler,Monika Ostap-Chęć,Wiktoria Rojek

doi:10.1002/ece3.4647

Abstract

Worker honeybees may reproduce in either their own or foreign colonies; the latter situation is termed intraspecific reproductive parasitism (IRP). In this study, we compared the tendency for IRP between normal honeybee workers, which are characterized by a relatively low reproductive potential, and “rebel workers”, a recently discovered subcaste of honeybee workers characterized by a high reproductive potential that develops when the colony is without a queen. We expected that the high reproductive potential of the rebel workers would influence their reproductive strategy and that these individuals would drift to other colonies to lay eggs more often than normal workers. The results confirm our expectations and show that rebel workers are more likely than normal workers to drift to foreign colonies. The rebel workers also preferred to drift to queenless colonies than to queenright colonies, while the normal workers did not show this preference. This study indicates that rebel workers have a tendency for IRP, which may be responsible for the maintenance of the rebel worker strategy in bee populations.

Highlights

Some species are vulnerable to infiltration by cheater individuals that lay eggs to be reared in conspecific nests
The increased reproductive potential and higher possibility of having activated ovarioles, even in queenright colonies, may influ‐ ence the behavior of rebel workers and increase the possibility that they will drift to foreign colonies to lay their unfertilized eggs. To better understand these aspects of social behavior, we investigated whether rebel workers truly enter foreign colonies more often than normal workers of the same age, and we determined how ovary development and activation influence the parasitic behavior of bees
The results of our study are the first to show that rebel workers, in‐ dividuals with a higher reproductive potential than normal workers, migrate to foreign colonies more often than normal workers

Summary

| INTRODUCTION

Some species are vulnerable to infiltration by cheater individuals that lay eggs to be reared in conspecific nests. The proximate factor that influences rebel caste development is the absence of a queen or, more precisely, the lack of a queen’s mandibular gland pher‐ omones (Woyciechowski, Kuszewska, Pitorak, & Kierat, 2017) during the larval feeding period (unsealed larvae) If they remain in a queenless or a queenright colony during their adult lifetimes, these rebel workers display active ovaries (Woyciechowski & Kuszewska, 2012) and have a higher number of male offspring than normal workers (Kuszewska, Wącławska, & Woyciechowski, 2018). To better understand these aspects of social behavior, we investigated whether rebel workers truly enter foreign colonies more often than normal workers of the same age, and we determined how ovary development and activation influence the parasitic behavior of bees

| METHODS

| DISCUSSION

Findings

CONFLICT OF INTEREST