Bioacoustics of Probolomyrmex

This genus was well and comprehensively revised by Taylor in 1965, and I find no reason to cover the same ground. Since his revision, however, 2 new species, P. bidens and P. procne [19, 20], have come to light, and the status of some old ones [21] require discussion, so that a revised species list and a few comments and records are offered here. In his generic diagnosis, Taylor characterizes the workerqueen sting as " well developed, " which scarcely does justice to the powerful structure as seen fully or nearly fully extruded in the syntype of P. dammermani (MCZ) reviewed by him. In this specimen, the extruded sting shaft is 0.52 mm long, with a thick base, as compared to a total gastric length of only 1.13 mm. A worker specimen of P. dammermani was dissected, and proved to be without the stridulatory file on the pretergite of gastric segment II, a condition I believe holds throughout the genus because of the " tight " fit of the second segment into the first gastric segment of all 9 species I examined externally for this character. The modest constriction between the first and second segments is seen clearly in side view, but is not usually apparent in dorsal view. The second gastric segment is not " fused " into a tube, as Taylor indicates; instead, the tergum and sternum separated easily and cleanly along lateral sutures, with only slight tension in a P. dammermani worker treated with KOH. The characters distinguishing Probolomyrmex from Platythyrea are cited in comparative form on p. 7.