Larval taxonomy of eastern Nearctic Polycentropus sensu stricto (Trichoptera: Polycentropodidae)

Abstract

Although the alpha taxonomy of male caddisflies (Trichoptera) is largely well resolved in North America north of Mexico, significant work is needed to improve knowledge of larval stages. The genus Polycentropus Curtis, 1835 (Polycentropodidae) typifies this fact, with larval descriptions available for only 5/29 Nearctic species. The speciose eastern Nearctic fauna represents 22/29 Nearctic species and exemplifies a larger gap in larval taxonomy, with larval descriptions available for only 1/22 eastern Nearctic species. The inability to identify these larvae to species level precludes studies on these organisms’ biology and their inclusion in water-quality bioassessment protocols. Based on molecularly identified larvae, we describe the late- or final-instar larvae of an additional 11/22 eastern species and redescribe the larvae of Polycentropus centralis Banks, 1914. Species for which larvae are newly described are Polycentropus alabamensis Hamilton, Harris, and Lago, 1990; Polycentropus blicklei Ross and Yamamoto, 1965; Polycentropus carlsoni Morse, 1971; Polycentropus carolinensis Banks, 1905; Polycentropus confusus Hagen, 1861; Polycentropus elarus Ross, 1944; Polycentropus floridensis Lago and Harris, 1983; Polycentropus maculatus Banks, 1908; and Polycentropus pentus Ross, 1941 of the Polycentropus confusus Species Group as well as Polycentropus colei Ross, 1941 and Polycentropus rickeri Yamamoto, 1966 of the Polycentropus colei Species Group. A diagnostic matrix to assist in their identification is provided, and 1 new state record is reported. Future efforts should focus on associating and describing remaining unknown larvae and building upon the data and diagnostic tools provided herein.