| The ecological immunology, sociobiology and sociogenetics of colony foundation were examined in the dampwood termite Zootermopsis angusticollis.; The significance of disease exposure during colony foundation was studied in primary reproductives. Females surviving a high dose of fungal pathogen produced significantly fewer eggs than controls during their first bout of oviposition, but this effect did not appear to compromise long-term fitness, as eventual colony growth was similar in all treatments. Exposure to a low dose of fungus did not reduce egg production.; Primary reproductives were challenged with a non-pathogenic nylon implant to study innate immunity without the complications of a live pathogen exposure. In the stage of colony foundation that coincides with copulation and oocyte maturation, mated females showed a reduced ability to encapsulate an implant, suggesting that the costs of oogenesis constrained immunocompetence. Males had a significantly greater encapsulation response than females, also indicating a trade off between reproduction and immunity.; The survival of nestmate and non-nestmate pairs following exposure to disease was compared. Primary reproductives survived significantly better when paired with a nestmate than with a non-nestmate. This survival advantage suggests that pairing with an individual from another colony (and thus outbreeding) may incur disease-related costs during colony foundation. Inbred and outbred colonies did not differ significantly in size, suggesting that lower offspring heterozygosity does not significantly impact colony growth.; The immunocompetence of offspring from inbred and outbred reproductive pairs was compared to address the hypothesis that reduced genetic variation decreases disease resistance. Several independent measures of immunocompetence indicated that reduced heterozygosity did not impact physiological immunity but may have affected social hygienic behaviors.; Finally, the immune responses of Z. angusticollis and Incisitermes schwarzi, which differ significantly in nest microbe diversity and abundance, were compared. Survivorship following pathogen exposure suggests that the immunocompetence of individuals and the advantages of group living have been maintained over evolutionary time independent of immunological pressures.; The significance of these studies on disease resistance is discussed in relation to the evolution of termite life history. |
