Polycentropus dinkinsorum Orfinger & Etnier, 2020

Orfinger, Alexander B. & Etnier, David A., 2020, Polycentropus dinkinsorum (Trichoptera: Polycentropodidae), a newly described caddisfly species from the southern Appalachian Mountains, USA, Zootaxa 4853 (1), pp. 126-132 : 127-129

Polycentropus dinkinsorum Orfinger & Etnier , new species

Figures 1 A–1D.

Description. General Structure: Length 6.1–7.2 mm (n = 4). General habitus typical of males of the P. confusus Species Group. In ethanol, eyes dark purple and glazed; body color various shades of brown, with subtle spots of lighter brown forming irrorate pattern on front wings; hind wings uniformly brown; legs tan to pale yellow.

Male genitalia ( Fig. 1 ). Abdominal segment VIII annular. Tergum IX fused with segment X, membranous, caudally extended as horn-like projection in lateral view ( Fig. 1A ). Sternum IX round in lateral view, posterior margin lobate. Intermediate appendages positioned beneath terga IX+X, distally extending beyond tergum X, apices each bearing 3 small setae; in lateral view ( Fig. 1A ) curved slightly ventrad; in dorsal view ( Fig. 1B ) apices proximate, parallel. Preanal appendages triangular in lateral view ( Fig. 1A ), each with posterior angle acute, forming tooth-like projection; in lateral view dorsal process wide basally, distally slender, terminating in long, whiplike process curved ventrad terminating in slender spine; in dorsal view ( Fig. 1B ) sub-parallel, slender, elongate. Inferior appendages each with ventral portion in lateral view gradually tapered, extended posterad slightly beyond intermediate appendages, ventral margin nearly straight; in ventral view ( Fig. 1C ), mesal projection near midlength, distal half curved inward; dorsobasal process in lateral view erect, with long “neck” terminating in short, rounded “head” projecting downward, in ventral view ( Fig. 1C ) obscured completely by ventral portion of inferior appendage. Phallus in lateral view ( Fig. 1D ) slightly curved ventrad, mesoventral protuberance arising near midlength, apical section rectangular, spinules absent, phallic sclerite moderately elongate with narrow distal portion.

Female and Larva: Unknown

Diagnosis. The male of P. dinkinsorum can be separated from those of all other currently known members of the P. confusus Species Group by the sharpness of the acute, tooth-like projection of the posteroventral margin on the body of the preanal appendage compared to the more blunt tooth-like projection of the posteroventral margin on the body of the preanal appendage, or absence of the tooth-like projection. Male genitalic structure is most similar to that of P. carolinensis and P. carlsoni . It can readily be separated from both P. carolinensis and P. carlsoni by the presence of a mesoventral protuberance on the phallus, the longer “necks” of the dorsobasal process of the inferior appendages, and the more obtusely curved “heads” of the dorsobasal processes of the inferior appendages. Males can also be distinguished from P. carlsoni by the slight downward curvature of the phallus, versus the stronger curvature exhibited by P. carlsoni , and the more obtusely curved head shape of the dorsobasal process of the inferior appendage. From P. carolinensis it can also be separated by the presence of a distinctly pronounced, horn-like, apical projection of the combined terga IX+X extending caudad over the intermediate appendages. From P. floridensis , P. pentus , and P. vernus , which each exhibit a ventral swelling on the phallobase, males of P. dinkinsorum can easily be separated by the more distal location of the mesoventral protuberance, the shape of the dorsobasal process of each inferior appendage. From P. floridensis and P. vernus , P. dinkinsorum can be distinguished by the presence of the acute, tooth-like projection of the posteroventral margin of the preanal appendage and from P. pentus by the prominent profile of this projection (set in a concavity in P. pentus ).

Material Examined. Holotype: USA. North Carolina: Henderson County, Flat Rock, Carl Sandburg Home National Historic Site, Malaise Trap, [N35°16’16.28, W82°27’01.04”], I. Hoff and E. Eleantar coll., 20-ix-2012, 1 male (USNMENT 01350618).

Paratypes: USA. West Virginia: Raleigh County, Piney Creek tributary, New River system, [N37°50’39.08”, W81°06’48.88”], G.R. Dinkins, B.J. Dinkins, and H.O. Faust coll., 25-vi-2014, 1 male ( CUAC000107314 ). North Carolina: Swain County, Great Smoky Mountains National Park, Kephart Prong Trail near trail head across from bridge over Oconaluftee River , blacklight trap, 834 m, [N35°35’11.52”, W83°21’32.87”], B. Sullivan coll., 23– 25-vii-2000, 1 male (USNMENT 01350619), 1 male ( FAMU), 1 male ( INHS Insect Collection 923902). North Carolina: Henderson County, Carl Sandberg Home National Historic Site, Flat Rock , Duck Pond , Malaise Trap, [N35°16’15.96”, W82°27’01.04”], I. Hoff and E. Eleantar coll., 16–24-v-2012, 1 male ( ROME184984 ). Haywood County , Great Smoky Mountains National Park , Mt. Sterling Trail , D. Paulsen coll., 27-vi-1989, 9 males ( UTK 3.269 ). Tennessee: Carter County , Roan Mountain State Park , black light, J. Ensminger coll., 6–12-viii-2000, 1 male ( CASENT8468186 ). Blount County , Great Smoky Mountains National Park , Sams Creek , 100 m below Thunderhead Creek , D. Etnier coll., 7-vi-1996, 1 male ( UTK 3.288 ) .

Comparative Material Examined. The comparative material examined ( Table 1) represents the remaining members of the P. confusus Species Group, with the exception of P. vernus Hamilton, Harris, & Lago 1990 for which the original description and illustrations were used. Type material was examined when available for most species, and all original descriptions were consulted.

Etymology. Named in honor of the family of Gerald R. and Barbara J. Dinkins, students, colleagues, and participants in many aquatic biology efforts throughout our long friendship. Their three adult “children”, Jamie, Timothy Charles (T.C.), and Zack, share our interests in science and the environment, and are also recognized in this species epithet.

Figures

FIGURE 1. Polycentropus dinkinsorum n. sp., male genitalia. 1A, left lateral (with phallus removed). 1B, dorsal. 1C, segment IX and inferior appendages, ventral. 1D, phallus, left lateral. Abbreviations: d.p. = dorsobasal process of a preanal appendage (paired); hl. p. = horn-like apical projection of terga IX+X; inf. app. = inferior appendage (paired); int. app. = intermediate appendage (paired); IX+X = combined terga IX + X; mv. prot. = mesoventral protuberance; ph. sc. = phallic sclerite; pre. app. = preanal appendage (paired); s.IX = sternum IX.