vvdC.yy Vol. 77, pp. 73-112 2fi June 1964 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON NATURAL HISTORY OF PLUMMERS ISLAND, MARYLAND 1 XVIII. The Hibiscus Wasp, an Abundant Rarity, and Its Associates ( Hymenoptera : Sphecidae ) By Karl V. Krombein Entomology Research Division, Agricultural Research Service, U. S. Department of Agriculture, Washington, D. C. The hibiscus wasp, Ectemnius ( Hypocrabro ) paucimaculatus ( Packard ) , is a rather small ( 9 , 6-8 mm long ) crabronine wasp with reduced yellow markings. Its closest relatives are E. stirpicola (Packard) and E. spiniferus (Fox). Until 1961 it was known from only a few specimens. There were 14 in the U. S. National Museum from scattered localities ranging from New Jersey to Florida, Texas and Missouri. The wasp was described from Illinois, and Fox ( 1898 ) in his revision re-corded it also from New Jersey, the District of Columbia, and Florida. Three of the specimens in the National Museum were reared from a hibiscus stem at Black Pond, Fairfax Co., Va., in 1919, by F. C. Craighead, but no reference was made in the original brief rearing notes as to whether the hibiscus stem was dead or alive. In 1961, while collecting at Plummers Island for an anno-tated list of the wasps of that locality (Krombein, 1963), I collected a male of E. paucimaculatus on 6 August along the Potomac River near the upper end of the island. In an attempt to secure some data on its life history, I tried to provide ready access to the soft pith in the hibiscus stems by topping a num-ber of green and of dead hibiscus stems on mud flats along the river. Several years earlier a similar program of topping stag-1 The preceding number in this series was published in Proc. Biol. Soc. Wash., 76: 255—280, 1963. Publication costs of the present number have been defrayed by the Washington Biologists' Field Club to promote its primary objective of research on the fauna and flora of Plummers Island and adjacent areas. 10— Proc Biol. Soc. Wash., Vol. 77, 1964 ( 73 ) MrrHSQKIAII wstitot JUN 2 6 «*^
BioStor
