Communication by electrical means in social insects.

Area of Science:

• Entomology
• Animal Behavior
• Thermoregulation

Background:

• Social insects, including hornets (Hymenoptera), maintain a stable nest temperature (29°C) across diverse climates.
• Thermoregulation is primarily achieved by adult insects through muscle activity (wing fluttering).
• Larval brood contributes to nest warming, but pupae, lacking developed muscles and enclosed in cocoons, present a thermoregulatory challenge.

Purpose of the Study:

• To investigate how hornet pupae communicate their thermal needs to adult hornets.
• To explore mechanisms beyond pheromonal signaling for thermoregulation in hornet colonies.
• To determine if pupae can actively relay temperature information.

Main Methods:

• Utilized thermometers and infrared (IR) rays to measure insect and nest temperatures.
• Investigated the role of adult muscle activity and larval heat contribution in thermoregulation.
• Examined the physiological capabilities of hornet pupae, including muscle development and cocoon structure.

Main Results:

• Adult hornets and larvae possess muscles for thermoregulation; pupae have undeveloped muscles.
• Pheromones attract adults to pupae but do not convey specific thermal data.
• Evidence suggests hornet pupae transmit body temperature information through electrical signals.

Conclusions:

• Hornet pupae can actively communicate their thermal status to adult hornets.
• Electrical signaling represents a previously unrecognized mechanism for thermoregulation in social insects.
• This finding enhances our understanding of colony-level temperature control and insect communication.