NEW DISTRIBUTIONAL RECORDS FOR PLATYSTETHUS (COLEOPTERA, STAPHYLINIDAE, OXYTELINAE) WITH NOTES ON THE BIOLOGY OF P-AMERICANUS

A survey of the fauna of cattle dung dropped naturally on pasture in A lachua County, Florida, revealed several species of Staphylinidae, inc luding two species of Platystethus. Adult Platystethus spiculus Erichs on were collected only in July 1991. Adult Platystethus americanus Eri chson were collected from March to June 1993. In the laboratory immatu re stages of P. americanus took 18-22 days to develop at 27 degrees C (2-3, 10-12, and 7 days for the egg, larval, and pupal stage, respecti vely). Some adults were offered cattle dung alone as diet in which the females deposited eggs in chambers. Some larvae were offered cattle d ung and horn fly [Haematobia irritans (L.)] larvae as diet, and the be etle larvae pupated successfully in chambers or partial chambers under the dung. Adults and larvae held without cattle dung ate horn fly lar vae, but females did not oviposit and beetle larvae did not pupate, mo st likely because they require dung or a similar substrate in which to make chambers. New distributional records are Florida and New Mexico for P. americanus, and St. Croix (U.S. Virgin Islands) and New Mexico for P. spiculus.