POPULATION ECOLOGY Nest Growth and Survivorship in Three Species of Neotropical Nasutitermes (Isoptera: Termitidae)

Long-term growth and survivorship of individual arboreal nests were studied in three species of Neotropical termites in the genus Nasutitermes. Of the 29 N. corniger (Motschulsky) and seven N. ephratae (Holmgren) nests monitored in an area of young second-growth in Panama, 12 (41%)N. corniger and four (57%)N. ephrataenests remained active throughout the 9to 11-mo study. There was no signiÞcant difference in survivorship between small and large nests of either species. In surviving N. corniger nests with a single queen, the net increase in volume was highly correlated (r 5 0.87, n 5 9) with queen wet weight. There was a marked seasonality to nest expansion in both N. corniger and N. ephratae, with growth occurring almost exclusively during the wet season. Seventeen N. acajutlae (Holmgren) nests were monitored for 4Ð9 yr on Guana Island, British Virgin Islands. Four of the 17 (23.5%)N. acajutlaenests survived the study period, and twomore abandoned their original nest and relocated. Within this limited sample of colonies, N. acajutlae nests that were large (.150,000 cm) at the beginning of the study had a higher probability of survival than did small (,100,000 cm) nests. Nest budding, relocation, and resprouting are mechanisms that Nasutitermes may use to create a new nest for all or a portion of an established colony. The ontogeny of incipient Nasutitermes colonies is discussed as a sequence in which a young colony remains cryptic within wood, building its population size to a point where the colony can maintain and defend a nest. Early in a wet season, termites then venture from within wood to build and occupy a small arboreal nest.