Barichneumon Thomson, 1893

Barichneumon is a moderately diverse genus (16 Nearctic species) of smaller-bodied ichneumonines. Females tend toward brownish-red, while the color in males is more variable. Morphologically Barichneumon is most similar to Melanichneumon. However, Barichneumon species are usually less richly colored than Melanichneumon and usually lack white spot on the metasomal apex which is typical of Melanichneumon. Barichneumon also lacks the strongly expanded flagellum in females and the crecent-shaped, or at least posteriorly impressed, areola that also characterizes Melanichneumon. Males of these two genera are quite similar, but in most cases, they can be confidently identified based on the shape of the areola and the more strongly developed bristle-ridges in Melanichneumon.

Also, Barichneumon and Stenobarichneumon are essentially identical except that the latter genus has wide thyridia (single thyridium wider than interthyridial width), and Stenobarichneumon species are normally darker in color with yellowish-white medial paraocular areas. Stenobarichneumon may be derived from within Barichneumon.

There are at least five undescribed Nearctic species.

Diagnosis

• female metasomal apex oxypygous
• gastrocoeli and thyridia small and narrow
• anterior margin of propodeum with medial protuberance
• metasomal apex usually without white marking