Rebel honeybee workers have a tendency to become intraspecific reproductive parasites

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.

Humoral and Cellular Defense Mechanisms in Rebel Workers of Apis mellifera

“…Thus, workers developing at larval stage in a queenless colony become relatively selfish individuals with higher reproductive potential than those that develop in a colony with a queen. These workers called rebel workers are characterized not only by their increased reproductive potential but also other altered anatomical features (e.g., less developed HGs, larger mandibular glands; [ 20 ]), shortened preimaginal development [ 22 ], prolonged life [ 23 ], different foraging preferences [ 24 ], tendency to drift to other colonies [ 25 ], increased sucrose sensitivity [ 26 ], energy reserves and protein concentrations in fat body [ 4 ], and increased learning ability [ 27 ].…”

Morphology of Nasonov and Tergal Glands in Apis mellifera Rebels

“…They have more ovarioles in their ovaries, as well as better developed mandibular glands and underdeveloped hypopharyngeal glands. Moreover, their ovaries are activated regardless of whether they live in queen-less or queen-right colonies [ 24 , 25 , 26 , 27 ]. Since the rebels are so anatomically and behaviorally different from the normal workers and more queen-like, the following questions arise: How do their gland cells function, and are they morphologically similar to the gland cells of queens or workers?…”

Honeybee workers with higher reproductive potential have a greater learning ability

“…These workers are called rebel workers (M Woyciechowski and Kuszewska 2012), and studies have shown that these individuals lay eggs more often than normal workers, even if they remain in a colony with a queen (Karolina Kuszewska et al 2018c). Compared to normal workers, rebel workers are characterised not only by their increased reproductive potential but also by their prolonged life (Karolina Kuszewska et al 2017), different foraging preferences (Kuszewska et al 2018b), tendency to drift to other colonies (Karolina Kuszewska et al 2018a) and increased sucrose sensitivity (Karolina Kuszewska et al 2019).…”