REPRODUCTIVE MECHANISMS AND DYNAMICS OF HABITAT COLONIZATION IN MICROCEROTERMES BIROI (ISOPTERA, TERMITIDAE)

1. Previous studies on the arboreal termite community in coconut plant ations of northern New Guinea showed that Microcerotermes biroi is the most abundant species, despite the fighting superiority of two compet itor species Nasutitermes princeps and N.novarumhebridarum. In this st udy we tested the hypothesis that the success of M.biroi is due to its efficiency at colonizing new habitats following nuptial flights. 2. W e demonstrated experimentally the ability of M.biroi colonies to repla ce their reproductives when removed, or to produce reproductives in sa tellite nests when isolated from the remainder of the colony. Replacem ent reproductives were always neotenics, derived from nymphs or worker s. 3. Despite the ability of neotenics to differentiate within their h ome colonies, 84% of field colonies were headed by dealated images. Th is value constitutes a minimum estimate of the proportion of field col onies founded independently by images after the nuptial flight. 4. The monitoring of a young plantation during the first 3 1/2 years of its colonization by arboreal nesting termites revealed its invasion by M.b iroi, which colonized 63% of the trees while neither Nasutitermes spec ies appeared. 5. Our results demonstrate that M.biroi is actually a pi oneer species, able to invade a new habitat by means of nuptial flight s. They outline the importance of each species' reproductive strategy in shaping the arboreal-nesting termite community.