Overcoming Immune Deficiency with Allogrooming

Area of Science:

• Ecology
• Insect behavior
• Immunology

Background:

• Social animals rely on allogrooming for parasite defense.
• In social insects, allogrooming removes pathogenic propagules from the cuticle.
• Subterranean termites encounter soil-borne fungal spores like Metarhizium.

Purpose of the Study:

• Investigate differences in social and innate immunity reliance in two related subterranean termite species.
• Determine how termites protect themselves from Metarhizium fungal infections.
• Assess termite allogrooming responses to fungal spore contamination.

Main Methods:

• Comparative study of two closely related subterranean termite species.
• Exposure to locally encountered Metarhizium fungal species.
• Observation and quantification of allogrooming behavior.
• Assessment of innate immune responses.

Main Results:

• One termite species exhibits weaker innate immunity compared to its relative.
• This species compensates with more sustained and enhanced allogrooming.
• Allogrooming increased with routine and heavy Metarhizium conidia contamination.
• Heavy contamination triggered a networked emergency response involving allogrooming.

Conclusions:

• Allogrooming is a critical social immune mechanism for subterranean termites, especially when innate immunity is limited.
• Termites demonstrate adaptable allogrooming strategies to manage different levels of fungal spore exposure.
• Social immunity, through allogrooming, plays a vital role in protecting termite colonies from fatal fungal infections.