Murray State University
The Effect of Temperature and Fungal Resistance on Termites, Nasutitermes acajutlae: Influences of Temperature and Resistance to a Pathogenic Fungus on Colony Growth and Individual Survival: STUDY 1 (Bell): The Relationship Between Ambient Temperature and Survival of the Tropical Termite Nasutitermes acajutlae
Institution
Murray State University
Faculty Advisor/ Mentor
Claire Fuller
Abstract
Due to climate change, the effect of temperatures on the interactions between organisms and their pathogens has been of great interest. While climate change has not been as pronounced in tropical regions as in temperate and arctic zones, it has no less effect as tropical species have narrow physiological tolerances. We investigated the relationship between ambient temperature and survival of the tropical termite Nasutitermes acajutlae on the island of St. John in the U.S. Virgin Islands. Our previous research showed that termites living in warmer, dryer areas had stronger immune systems and were less susceptible to fungal pathogens. However, we also found high levels of variation among termite colonies. The current study replicates these findings to determine the extent of colony-level variation. We collected termites from nests within warm and cool environments and exposed them to four levels (control, 103, 105, 107 spores per ml) of the known insect pathogen Metharizium anisopliae. Once the termites were exposed the replicates were incubated at two different temperatures and checked twice daily to determine the number of surviving termites. The data were analyzed using survival analysis. As expected, the termites from nests in warm, dry habitats had higher survival rates. However, the influence of individual colony was more important than the influence of climate. We hypothesize that these colony-level differences are genetically determined and predict that colonies with similar levels of survival will be genetically similar. We are developing genetic techniques to test this prediction.
The Effect of Temperature and Fungal Resistance on Termites, Nasutitermes acajutlae: Influences of Temperature and Resistance to a Pathogenic Fungus on Colony Growth and Individual Survival: STUDY 1 (Bell): The Relationship Between Ambient Temperature and Survival of the Tropical Termite Nasutitermes acajutlae
Due to climate change, the effect of temperatures on the interactions between organisms and their pathogens has been of great interest. While climate change has not been as pronounced in tropical regions as in temperate and arctic zones, it has no less effect as tropical species have narrow physiological tolerances. We investigated the relationship between ambient temperature and survival of the tropical termite Nasutitermes acajutlae on the island of St. John in the U.S. Virgin Islands. Our previous research showed that termites living in warmer, dryer areas had stronger immune systems and were less susceptible to fungal pathogens. However, we also found high levels of variation among termite colonies. The current study replicates these findings to determine the extent of colony-level variation. We collected termites from nests within warm and cool environments and exposed them to four levels (control, 103, 105, 107 spores per ml) of the known insect pathogen Metharizium anisopliae. Once the termites were exposed the replicates were incubated at two different temperatures and checked twice daily to determine the number of surviving termites. The data were analyzed using survival analysis. As expected, the termites from nests in warm, dry habitats had higher survival rates. However, the influence of individual colony was more important than the influence of climate. We hypothesize that these colony-level differences are genetically determined and predict that colonies with similar levels of survival will be genetically similar. We are developing genetic techniques to test this prediction.