Low temperature triggers sociality in a facultatively social bee

Area of Science:

• Evolutionary biology
• Behavioral ecology
• Entomology

Background:

• The evolution of eusociality from solitary ancestors is a major transition in insect evolution.
• Environmental factors may have initiated group living, leading to sociality.
• Facultatively social insects exhibit plasticity in social behavior in response to environmental cues.

Purpose of the Study:

• To identify specific environmental cues that trigger solitary or social nesting decisions in insects.
• To investigate the role of environmental plasticity in the evolution of insect sociality.

Main Methods:

• Experimentally exposed the facultatively social allodapine bee Exoneura robusta to manipulated temperature and predation cues.
• Utilized climate chambers for controlled environmental treatments.
• Observed and quantified social behavior in individual bees.

Main Results:

• Low temperatures were identified as a specific environmental cue that induced more social behavior in Exoneura robusta.
• Substantial variation in the tendency towards social behavior was observed among individual bees.
• Demonstrated a direct link between an environmental cue and a plastic social response.

Conclusions:

• Environmental plasticity, specifically triggered by low temperatures, plays a crucial role in the evolution of sociality.
• Identified low temperature as a key trigger for social behavior in facultatively social bees.
• This plasticity may have been critical in the evolutionary origin of group living and social breeding in insects.