Termite caste differentiation: a social affair.

摘要

This paper briefly explains what social insects are, defines the different castes of insects and their corresponding responsibilities, the intricacies and complexities of caste differentiation, particularly termite caste differentiation, and the factors that determine which caste an individual becomes a part of. Examples of factors affecting caste differentiation include nutritional status, age, hormonal levels, genetic composition or sex of the individual (internal factors), and the number of caste members already present within the colony, temperature or moisture (external factors). Current research show that chemicals from soldiers influence the fate of nestmates around them. Chemicals present in soldier heads when applied in combination with an insect hormone (juvenile hormone) cause worker termites to moult into soldiers. When a soldier dies, primer pheromones in the corpse stimulate worker nestmates to moult into soldiers to replace the soldier that was lost. This chemical communication helps the colony maintain balance between the number of individuals that are of a specific caste, keeping the colony as efficient as possible. This discovery may be used to develop environmentally friendly, termite-specific control methods.