Papers in the Biological Sciences


Date of this Version



Published in the Journal of Parasitology (June 1997) 83(3): 502-507. Copyright 1997, the American Scoeity for Parasitologists. Used by permission.


The septate gregarine parasites of flour beetles (Tribolium spp.) include Gregarina minuta Ishii, 1914, a relatively small species in which both primite and satellite possess an obvious protomerite, and a larger species that lacks the satellite protomerite. The latter species has been placed in the genera Didymophyes and Hirmocystis by various authors, but studies reported here demonstrate that this species, herein described as Gregarina triboliorum, exhibits early pairing and produces oocyst chains, both characteristics of the genus Gregarina. The oocysts of this new species are described for the first time. In addition, experimental infections using oocysts from single gametocysts reveal that oocyst chain number is variable but is typically one, two or four. Prior experiments involving a related beetle, Tenebrio molitor, demonstrated extreme host specificity within the four Gregarina species parasitizing larval and adult hosts. However, G. triboliorum is not limited either stadially or specially, infecting both adults and larvae of Tribolium confusum and Tribolium castaneum.