Natural History and Immunity in a Caribbean Termite: a 10 Year Study

Termites are highly important in recycling of woody debris into soils, particularly in tropical ecosystems. Termites are social organisms, living in colonies of up to 500,000 individuals. Living in social groups increases the risk of contracting infectious diseases. This, in conjunction with human-induced problems such as climate change and habitat degradation, could negatively affect the termites, and therefore, soil production. Previous short-term research showed that temperature and humidity affect reproduction, survival, aspects of immunity and susceptibility to fungal disease in the Caribbean termite, Nasutitermes acajutlae. To determine the magnitude of these affects, we conducted a 10- year study on the island of St. John, USVI. We measured the relationship between abiotic climate variables including light, soil moisture, soil temperature, relative humidity and temperature inside and out of selected nests, and biotic variables: survival, growth and reproduction of termite colonies. We are also further examining how their immune system is affected by their habitat. Previous research documented that one aspect of termite immunity (phenoloxidase activity) increases with temperature, as does susceptibility to fungal infections. To determine the affect of habitat on a second aspect of immunity, we are examining fat content of termite bodies taken from the multiple microclimates. We will present the relationship between environmental conditions and termite survival, growth, reproduction and immunity. This study provides insight into how climate change might affect soils and wood recycling in tropical ecosystems