Diet-mediated inter-colonial aggression in the formosan subterranean termite Coptotermes formosanus

Area of Science:

• Behavioral Ecology
• Chemical Ecology
• Social Insect Behavior

Background:

• Intercolonial aggression in social insects often relates to territoriality.
• Cuticular hydrocarbons (CHCs) and genetic relatedness are implicated in termite nestmate recognition and aggression.
• Previous studies on Coptotermes formosanus aggression showed ambiguous roles for CHCs and genetics, suggesting other factors.

Purpose of the Study:

• To investigate the influence of genetic relatedness, CHC profiles, and diet on inter-colony aggression in Coptotermes formosanus.
• To identify potential factors beyond genetics and CHCs in nestmate recognition for this termite species.

Main Methods:

• Collected four C. formosanus colonies from Louisiana, fed on bald cypress or birch.
• Assessed inter-colony aggression levels.
• Determined genetic distances using microsatellite DNA markers and analyzed CHC profiles; manipulated diet in laboratory experiments (spruce).

Main Results:

• Inter-colony aggression varied significantly.
• Neither genetic distance nor CHC profiles correlated with aggression levels.
• Termite diet (host tree) significantly impacted aggression; aggression decreased when colonies were fed the same wood.

Conclusions:

• Diet plays a crucial role in modulating aggression in C. formosanus, independent of genetic relatedness or CHC profiles.
• Diet-derived chemicals, identified via headspace solid-phase microextraction, may be key mediators in complex nestmate recognition.