Colony composition, phasic reproduction, and queen–worker dimorphism of an oriental non-army ant doryline Cerapachys sulcinodis species complex in northern Thailand

Abstract

The ant subfamily Dorylinae consists of the true army ants and non-army ant genera. The biology of these non-army ants is important in discussing the evolution of the army ant adaptive syndrome. We report on the colony composition, morphological characteristics, and phasic reproduction of a non-army doryline ant Cerapachys sulcinodis species complex collected in northern Thailand. Colony size was up to 1850 workers, which is larger than that of other non-army doryline ants. Unlike the true army ants, most colonies were polygynous. The queens were ergatoid (permanently wingless) and distinctively larger than the workers, but morphological specialization was not as strong as in army ant queens. The workers showed large variation in body size, but they have no distinctive subcastes like many genera of true army ants. These biological characteristics indicated that the C. sulcinodis complex has an atypical biology which are reminiscent of the army ant adaptive syndrome.