Polycentropus maculatus Banks

(Figures 2, 24–25, 48)

Polycentropus maculatus Banks, 1908: 65, fig. 6, J; type locality ′ Grand Lake, Newfoundland ̍ (MCZ) .

Polycentropus maculatus Betten, 1934: 221 .

Polycentropus maculatus Milne, 1938: 88 (as junior synonym of P. confusus Hagen, 1861). Polycentropus maculatus Ross, 1944: 65, fig. 243, J; fig. 258, allotype ♀.

Polycentropus maculatus Marshall and Larson, 1982: 25, fig. 48, J.

Polycentropus maculatus Nimmo, 1986: 197, figs. 147–150, J; figs. 151–152, ♀. Polycentropus maculatus Armitage and Hamilton, 1990: figs. A–D, J; figs. E–F, ♀. Polycentropus maculatus Hoffman and Morse, 1990: 278–280, figs. 9–12, ♀.

Diagnosis. Males of Polycentropus maculatus are most similar to males of P. chelatus, P. neiswanderi and P. stephani in the strong downward curvature of the phallus beyond its middle, and to P. carolinensis and P. carlsoni in the blade-like curvature of the ventral portion of each inferior appendage in ventral view. Males of P. maculatus are separable from those of P. chelatus, P. neiswanderi, and P. stephani by the posteroventral triangular process of the body of each pre-anal appendage and by the blade-like shape and breadth of the ventral portion of each inferior appendage in ventral view. From those of P. carolinensis and P. carlsoni, males of P. maculatus are distinguished by the strong downward curvature of the phallus and shape of the basodorsal process of each inferior appendage.

Females of P. maculatus are readily distinguished from all other females of the Polycentropus confusus species group except that of P. neiswanderi by the ventrally recurved apex of the external parts of gonopods VIII. From P. neiswanderi, females of P. maculatus are distinguished by the shape of the internal parts of the gonopods, which are broad, subrectangular, and tapered anterad in P. maculatus vs narrow, oblong, and tapering at the posterior apex in P. neiswanderi .

Adult description

General (Figure 2). Length of male 5.0– 6.2 mm (mean = 5.7 mm; n = 5). Length of female 5.6–8.5 mm (mean = 7.1 mm; n = 5).

Male genitalia (Figure 24A–E). Abdominal segment VIII annular. Terga IX and X fused, membranous, extended caudad over bases of intermediate appendages. Sternum IX ovoid in lateral view, posterior margin slightly sinuous. Intermediate appendages originating beneath terga IX+X and extending beyond them, curved ventrad, their apices each bearing 5 small setae; in dorsal view apices proximate, subparallel. Bodies of pre-anal appendages each with triangular posteroventral process; dorsal process long, curved ventrad, extending below head of basodorsal process of corresponding inferior appendage, acute apically; in dorsal view slender, elongate, subparallel, apices appearing recurved slightly laterad. Inferior appendages in lateral view each with capitate basodorsal process erect with moderately long neck and subtriangular head round dorsally and projecting ventrad with its pointed apex visible above main body of appendage, main body of appendage with dorsal and ventral margins subparallel for 2/3 length then convex subapicoventrally and tapering to acute upturned apex extended posterad slightly beyond intermediate appendages; in ventral view divergent, each blade-like, wide basally, distally tapering to pointed apex, inner margin slightly sinuous, basodorsal process completely hidden by main body of inferior appendage, in cleared specimen broad, with medial pointed projection; in caudal view oblong, with medial projection round. Phallus a fully sclerotised tube, in lateral view with larger base, curved about 90° ventrad slightly beyond mid-length, apical section subrectangular, internal spinules absent, internal phallic sclerite short, vertical, with round ventral base and tapered dorsal vertex.

Female genitalia (Figure 25A–B). Venter VIII in ventral view with ventral plates convergent, narrow, subtriangular, tapering apically, covered with setae; in lateral view each terminating in round posterior apex; posterior apex of external parts of gonopods VIII in ventral view with posterior margin subtriangular and round mesally; in lateral view extending beyond ventral plates in flat process with its tiny apex recurved ventrad; internal parts of gonopods VIII in ventral view visible through venter VIII even in uncleared specimen, appearing longitudinally wrinkled, darker than surrounding tissue, subparallel, elliptical, with round posterior apices distinctly posterior of apices of ventral plates, anterior ends tapered, extending to sclerotised external part of gonopods VIII at basal third of ventral plates; in ventral view anterior part of genital chamber sclerotised, strongly sinuous, wrapping around posterior apex of processus spermathecae; anterior apex extending anterad beyond sclerotised external part of gonopods VIII, posterior apex with subovoid projection on either side of processus spermathecae; processus spermathecae subovoid with central elevation bearing opening of ductus spermathecae.

Larva. Described by Orfinger et al. (2023)

Pupa. Unknown.

Biology. Adults have been collected from May to October from riparian habitat of small streams to small rivers, most often with cobble substrate. This species is among the more common eastern Nearctic Polycentropus species and is often collected syntopically with other members of the species group, most often P. confusus, P. blicklei and P. carolinensis .

Distribution (Figure 48). Canada: Newfoundland and Labrador, Nova Scotia, Ontario, Quebec; USA: Connecticut, Kentucky, Maine, Massachusetts, New Hampshire, New Jersey *, New York, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Vermont, Virginia, West Virginia.

Despite extensive sampling of Illinois by Ross and others and Michigan by Houghton and others, P . maculatus has not been recorded from either of these states, even though it is recorded from neighbouring Ohio and Kentucky. Similarly, because P. maculatus has been recorded from neighbouring states and provinces, it likely also occurs in Delaware, Rhode Island, Maryland, and New Brunswick.

Material examined. Holotype: Canada. Newfoundland and Labrador: Grand Lake, O. Bryant coll., 28-vii-1906, 1 male (MCZ Entomology 11,550) . Allotype: USA. Tennessee: Sevier County, Great Smoky Mountains National Park, Chimneys Campgrounds, At Light, A.C. Cole coll., 16-vii-1939, 1 female (INHS Insect Collection 37,261) .

Non-type material. USA. New]ersey: Burlington County, Brendon T Burns State Forest, Mt Misery, [N39°54 ʹ 58.09″, W79°30 ʹ 52.69″], S. Harris coll., 3-vii-2012, 5 females (FAMU) . new state record. New York: Clinton County, Deep Inlet Brook, Chazy Lake Road, [N44° 35 ʹ 46.32″, W73°50 ʹ 18.60″], L. Myers and C. Binggeli coll., 31-vii-2008, 1 male (BYU) . Adirondack Park, Bear Brook near Blue Mountain Lake, Frison and Ross coll., 19-vi-1941, 1 female (INHS Trichoptera 54,335) . North Carolina: Jackson County, Balsam Mtn. Preserve, 6.6 km E. Sylva, S. Fork Sugarloaf Creek, Malaise-Townes trap, 1180 masl, [N35° 22 ʹ 17.04″, W83°06 ʹ 37.08″], J.C. Morse coll., 3–6-vi-2019, 3 males, 6 females (CUAC000093025) . Balsam Mtn. Preserve, 4.5 km E. Sylva, S Fork Sugarloaf Creek, 1164 masl, [N35°22 ʹ 16.86″, W83°06 ʹ 36.11″], M.W. Green coll., 20-ix-2019, 1 male (CUAC000092984) . Macon County, E Fk Overflow Cr., 790 masl, [N35°01 ʹ 04.44″, W83° 14 ʹ 42.36″], R.L. Heth coll., 23-vii-2018, 1 male (CUAC000107327) . Ravenel Lake at Highlands Biological Station, 1250 masl, [N35°03 ʹ 14.40″, W83°11 ʹ 22.92″], M.A. Floyd coll., 19-vi-2019, 1 male (CUAC000088820) . Pennsylvania: Schuylkill County, Owl Creek, [N40° 46 ʹ 58.80″, W75°57 ʹ 39.60″], T. Bringloe, V. Harvey, S. Ripley, K. Rondollo coll., 18-vi-2013, 1 male (BIOUG06970 - G 02) . Rattling Run, [N40°35 ʹ 02.40″, W76°01 ʹ 01.20″], 1 male (BIOUG07980 - H 09) . 1 male (BIOUG07980 - H 11) . 1 male (BIOUG07980 - H 10) . Tennessee: Blount County, Jakes Creek at Elkmont, UV light, J.K. Moulton coll., 27-vii-2005, 1 male (FAMU) . Monroe County, Cherokee National Forest, Bald River at Holly Flats Recreation Area, 667 masl, [N35°17 ʹ 11.04″, W84°10 ʹ 41.88″], Holzenthal, Blahnik, Hamilton, Chamorro L., and Robertson coll ., 31-v-2003, 1 male (UMSP 000102505) . Morgan County, Crooked Fork at Petros, Rt. 116 ′fire department̍, J.K. Moulton coll., 10-v-2006, 1 male, 3 females (FAMU) . Sevier County, Great Smoky Mountains National Park, Chimneys Campgrounds, Ross and Stannard coll ., 1-ix-1948, (missing abdomen), 1 female (INHS Trichoptera 54,336) . West Virginia: Hardy County, 3 miles north-east of Mathias, [N38°33 ʹ 00.00″, W78° 29 ʹ 24.00″], D. Smith coll., 7-vi-2007, 1 male (BYU) . Mingo County, Laurel Creek, 2 miles east of Dingess, Kondratieff and Kirchner coll., 27-v-1993, 1 male (BYU) .