Pheromonal contest between honeybee workers (Apis mellifera capensis)

Area of Science:

• Entomology
• Animal Behavior
• Chemical Ecology

Background:

• Queenless honeybee workers (Apis mellifera capensis) can develop into reproductives called pseudoqueens.
• While morphologically workers, pseudoqueens are physiologically queenlike, reproduce, and emit queen-like pheromones.
• Intracolonial selection determines which workers become pseudoqueens, with only a few attaining this status after queen loss.

Purpose of the Study:

• To investigate the role of mandibular gland pheromones in the selection of pseudoqueens in Cape honeybees.
• To determine if workers compete to produce queen-like pheromone signals.
• To understand the signaling mechanisms underlying pseudoqueen development.

Main Methods:

• Analysis of mandibular gland pheromones from Cape honeybee workers.
• Experimental setup involving pairs of workers to observe pheromone production and competition.
• Identification and quantification of pheromone compounds, including 9-keto-2(E)-decenoic acid (9-ODA).

Main Results:

• Cape honeybee workers compete to produce the strongest queen-like pheromone signals.
• The queen substance, 9-keto-2(E)-decenoic acid (9-ODA), plays a role in suppressing worker pheromone secretion.
• Workers capable of producing potent queen-like signals are more likely to gain pseudoqueen status.

Conclusions:

• Worker competition for pseudoqueen status involves the production of queen-like pheromone signals.
• The intensity of queen-like pheromones secreted by workers is a key factor in reproductive selection.
• Understanding these pheromonal interactions provides insight into social organization and reproductive strategies in honeybees.