A New Dibrachys with a Key to the Nearctic Species (Hymenoptera: Pteromalidae)

E. E. Grissell


Dibrachys pelos n. sp. is described from adults, larvae, and eggs reared from prepupae of Sceliphron caementarium (Drury) and nests of Osmia nigrifrons (Cresson) containing prepupae of Stelis chlorocyanea Cockerell. In the laboratory, D. pelos completed development in 19 to 23 days on the hymenopterous larvae of Sceliphron, Ancistrocerus, Tachytes, Stelis, and Megachile. A key and figures are given for the 5 Nearctic species of Dibrachys: cavus (Walker), confusus (Girault), daphne Girault, pelos Grissell, and saltans (Ratzeburg). Nearctic specimens previously reported as D. maculipennis Szelenyi are considered a misidentification of D. confusus. D. maculipennis is a Palearctic species.

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