Macrotermes bellicosus

Lore & Background

Macrotermes bellicosus exhibits two worker castes: major and minor. Workers begin by caring for the queen, then leave the nest to forage. Major workers exit between 13 and 25 days after moulting, minor workers between 9 and 32 days. Outside the nest, minor workers primarily build underground passages during exploration, while major workers dominate food gathering once food is discovered. The ratio of major to minor workers shifts accordingly. Gut content analysis reveals two feeding groups: most workers have dark brown abdomens from feeding on the fungus comb, while a smaller number have reddish-brown abdomens from plant litter. Major workers are the primary consumers of plant litter and dominate fungus comb construction and food processing.

Reader's Guide

Macrotermes bellicosus is significant for demonstrating how environmental pressures shape behavior and colony success. In Comoé National Park, forest mounds are dome-shaped with thick walls to retain heat, while savanna mounds have thin walls and complex structures to shed heat faster. Predation risk influences foraging: in the savanna, food abandonment increases gradually with predation, while in the forest, food is abandoned immediately. Despite lower food availability and higher predation in the savanna, savanna colonies reproduce more frequently, produce more offspring, and have higher mound growth rates, leading to greater lifetime reproductive success than forest colonies. Interspecific competition with other detritivorous termites is suggested by complementary foraging patterns in the savanna during the rainy season. The species also uses caste-specific pheromones: minor worker trails attract both castes and convey food information only to major workers, while major worker trails may be antagonistic, helping divide labor among food sources.

Did You Know?

• Major workers have reddish-brown abdomens from consuming plant litter, while most workers have dark brown abdomens from feeding on the fungus comb.
• In the savanna, M. bellicosus mounds have thin walls and complex structures to shed heat faster, while forest mounds are dome-shaped with thick walls to retain heat.
• Savanna colonies of M. bellicosus have higher lifetime reproductive success than forest colonies, despite lower food availability and higher predation risk.