Monthly fluctuation of termite caste proportions (Isoptera) within fire ant mounds (Hymenoptera : Formicidae)

摘要

Monthly abundance and caste proportions of subterranean termites (Reticulitermes spp.) inhabiting red imported fire ant (Solenopsis invicta Buren) mounds were recorded during 1999 and 2000 from a relatively undisturbed forest edge in Tuskegee, Alabama. Temperature data were also recorded at these mounds; mean air, soil, and mound temperatures followed a sine model over the course of the year. During the late fall and early winter, relative proportion of young workers (< 3(rd) instar) increased from 0 to 66.7% of the sample from the previous month, suggesting a change in temperature requirements among termite castes. These data demonstrate that Reticulitermes spp. termites are found year-round inhabiting active fire ant mounds, although relative caste proportions change seasonally. The hypothesis of a minimum soil temperature determining the movement of young Reticulitermes spp. workers into fire ant mounds (or other locations of increased temperature) is discussed.