Sensory plasticity in a socially plastic bee.

Area of Science:

• Evolutionary biology
• Animal behavior
• Sensory ecology

Background:

• Social insects, particularly Hymenoptera, offer insights into the co-evolution of sociality and sensory systems.
• Antennal sensilla in Hymenoptera are crucial for processing olfactory social cues, with social species exhibiting denser sensilla for nestmate recognition.
• Previous research suggests a link between sociality and antennal sensilla density.

Purpose of the Study:

• To investigate population-level variations in antennal sensilla numbers in the socially plastic sweat bee Halictus rubicundus.
• To determine if sensilla density differs between populations experiencing varied climates and social expression.
• To explore the developmental plasticity of olfactory sensilla density.

Main Methods:

• Comparative analysis of antennal sensilla numbers across different populations of Halictus rubicundus.
• Experimental manipulation involving transplantation of bees between regions with differing environmental conditions.
• Examination of offspring sensilla density in relation to maternal environment and nesting behavior.

Main Results:

• Significant population differences were observed in both olfactory and hygro/thermoreceptive sensilla numbers.
• Olfactory sensilla density demonstrated developmental plasticity; offspring developed in a different region showed higher density than their transplanted mothers.
• No correlation was found between sensilla density and individual or nest phenotype (social vs. solitary).

Conclusions:

• Sensory systems, specifically antennal sensilla density, exhibit plasticity in response to environmental factors in Halictus rubicundus.
• This general sensory plasticity may provide adaptive flexibility for optimizing sensory perception in diverse environments.
• While sensory plasticity might facilitate social plasticity, it does not appear to be a direct cause of it in this species.