Rhyacophila nigrocephala, Iwata, 1927

Sun, Changhai, 2017, Two new species of the Rhyacophila nigrocephala species group from China (Insecta, Trichoptera, Rhyacophilidae), European Journal of Taxonomy 300, pp. 1-10 : 3

Rhyacophila nigrocephala species group

Diagnosis (modified from Schmid 1970)

The species group can be diagnosed by the combination of following characters. In the male, segment IX is usually long, with the apicodorsal lobe fused with the preanal appendages into a complex, covering the other portion of the male genitalia. The anal sclerites are fused, with the apex slightly incised mesally and curved upwards, its root is large and curved upwards. The tergal band is slender, flattened dorsoventrally, with the apex sagittal, and has been termed as the sagittal appendage by Ross (1956). The apical band is with two lateral arms articulating, with anal sclerites above and with the tergal band beneath. The phallic apparatus is elongate and cylindrical; the aedeagus with the apex is thin; the parameres, if present, are slender. Schmid (1970) recognized two sub-groups, the R. manuleata subgroup and the R. nigrocephala sub-group.