Trogomorpha Ashmead, 1900
Trogomorpha is a small, primarily Neotropical genus with two Nearctic species: Trogomorpha arrogans and Trogomorpha trogiformis. Both of these species are easily recognizable based on coloration alone. Trogomorpha arrogans is the only brownish-red Nearctic ichneumonine with dark wings with a yellowish band in the middle. Trogomorpha trogiformis is brownish-red except for the entirely black wings and yellowish apical tarsomeres.
Both species occur in open habitats. Trogomorpha arrogans is restricted to the southeastern U.S. and Mexico. T. trogiformis occurs in the eastern U.S. as far north as New York, but its southern and western extent is not clear. In eastern Texas, these two species potentially interbreed as evidenced by seemingly intermediate forms with overall black wings but with small yellow spots. Alternatively, T. arrogans and T. trogiformis may represent mere color morphs of the same species. There are no undescribed species in the Nearctic, but there are a few in the Neotropics.
Heinrich (1971) reported that Trogomorpha trogiformis has been reared from Ephyriades brunnea, a skipper butterfly. Further biological studies on Trogomorpha are needed to answer outstanding questions such as if females oviposit into larvae or pupae (or both) and the significance of the enlarged mandibles.
Diagnosis
- clypeus not separated from supraclypeal area by groove
- mandibles wide with subequal teeth (similar to that seen in the Listrodromus genus-group)
- propodeum sloping (without distinct dorsal and posterior faces)
- propodeal carinae absent
- female metasomal apex oxypygous
- males with well-developed bristle ridges on flagellum