Polycentropus carolinensis Banks, 1905

Orfinger, Alexander Benjamin, 2023, Taxonomic revision of the Polycentropus confusus species group (Trichoptera: Polycentropodidae), Journal of Natural History 57 (41 - 44), pp. 1825-1916 : 1845-1848

Polycentropus carolinensis Banks

( Figures 11–12 , 40 )

Polycentropus carolinensis Banks, 1905: 217 , J; type locality ′ Black Mountains , North Carolina ̍ (AMNH).

Polycentropus carolinensis Betten, 1934: 220–221 .

Polycentropus carolinensis Milne, 1936: 88 (as junior synonym of P. confusus Hagen, 1861 ). Polycentropus carolinensis Nimmo, 1986: 195 , figs. 117–121, J.

Polycentropus carolinensis Armitage and Hamilton, 1990 : figs. A–D, J.

Diagnosis. Males of Polycentropus carolinensis are most similar to those of P. aileenae , P. carlsoni and P. maculatus . Males of P. carolinensis are distinguished from those of these similar species by the smaller, rounder, head of the basodorsal process of the inferior appendage which appears thumb-shaped laterally. Additionally, the bodies of the pre-anal appendages in P. carolinensis are produced posterad far beyond those of P. carlsoni and exhibit a posteroventral corner and slightly emarginate ventral margin not seen in P. carlsoni but do not possess the posteroventral processes seen in P. aileenae and P. maculatus .

Females of P. carolinensis are most similar to those of P. aileenae , P. blicklei , P. carlsoni and P. maculatus . Females of P. carolinensis can be distinguished from females of the above-mentioned species in ventral view by the narrow, oblong, subparallel ventral plates and semi-trapezoidal anterior part of the genital chamber.

Adult description

General. Length of male 5.2–7.2 mm (mean = 6.1 mm; n = 5). Length of female 6.1– 8.8 mm (mean = 7.3 mm; n = 4).

Male genitalia ( Figure 11A–E ). Abdominal segment VIII annular. Terga IX and X fused, membranous, extended caudad over bases of intermediate appendages. Sternum IX subovoid in lateral view, posterior margin nearly straight. Intermediate appendages originating beneath terga IX+X and extending beyond them, curved slightly ventrad, their apices each bearing 3 small setae; in dorsal view apices proximate, subparallel. Bodies of pre-anal appendages each produced posterad, round dorsally with posteroventral corner and slightly emarginate ventral margin; dorsal process long, curved ventrad, extending level to basodorsal process of corresponding inferior appendage, acute apically; in dorsal view slender, short, slightly convergent, bases appearing recurved slightly laterad. Inferior appendages in lateral view each with thumb-like basodorsal process erect with moderately long neck and small head round dorsally and projecting ventrad with its blunt apex visible above main body of appendage, main body of appendage with dorsal and ventral margins tapering evenly along length to dorsally upturned apex extended posterad slightly beyond intermediate appendages; in ventral view subparallel, basal 1/3 wide, distal 2/3 abruptly tapered, inner margin concave, apices inflected mesally, basodorsal process completely hidden by main body of inferior appendage, in cleared specimen small, 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 25° ventrad slightly beyond mid-length, apical section subrectangular, internal spinules absent, internal phallic sclerite short, oriented dorsoposterad, thumb-like with pointed base and round apex curved dorsad.

Female genitalia ( Figure 12A–B ). Venter VIII in ventral view with ventral plates subparallel, narrow, oblong, tapering basally and apically, covered with setae; in lateral view each terminating in round posterior apex oriented posteroventrad; posterior apex of external parts of gonopods VIII in ventral view with posterior margin nearly linear; in lateral view extending posterodorsad above ventral plates in tapered process with its apex acute; internal parts of gonopods VIII in ventral view visible through venter VIII even in uncleared specimen, appearing longitudinally wrinkled, darker than surrounding tissue, convergent, semi-elliptical, with round posterior apices distinctly anterior of apices of ventral plates, anterior ends round, extending to sclerotised external part of gonopods VIII at basal third of ventral plates; in ventral view anterior part of genital chamber sclerotised, semi-trapezoidal, wrapping around posterior apex of processus spermathecae; processus spermathecae ovoid with central elevation bearing opening of ductus spermathecae.

Larva. Described by Orfinger et al. (2023).

Pupa. Unknown.

Notes. Ross (1944) speculated that three female specimens from Illinois represented either an undescribed species or the female of P. carolinensis . Ross termed these specimens, listed as being housed at the Illinois Natural History Survey but unable to be located, ′ Polycentropus species a̍ and provided a description and a ventral genitalic illustration ( Ross 1944). Unzicker et al. (1970) reported a specimen of the same species from Big Clifty, Carrol County, Arkansas, which also could not be located. The positive association and description of the female of P. carolinensis in the present study indicates that ′ Polycentropus species a̍ does not represent P. carolinensis , which has yet to be recorded from Illinois. The identity of these specimens remains unresolved.

Biology. Adults of P. carolinensis have been collected from May to July. Late-instar larvae have been collected from May to August and the few pupae have all been collected in May. This somewhat uncommon species is found in seeps and first- and second-order streams, usually at elevations above 1000 masl. The pupal shelter of P. carolinensis is constructed from plant material including sticks and leaves.

Distribution ( Figure 40 ). Canada: Ontario, Quebec; USA: Kentucky, Mississippi, North Carolina , New Hampshire, Ohio, Pennsylvania, Tennessee, Vermont, Virginia, West Virginia.

Nimmo (1986) indicated the fragmentary nature of the known distribution of P. carolinensis at the time. Although several new state and province records have since been reported, the known distribution remains patchy. There are several areas in the Midwest (e.g. southern and eastern Indiana), north-east (e.g. Maryland, New York), and south-east (e.g. northern Alabama, northern Georgia, and north-western South Carolina ) where this species may be found. It will most likely be recovered in or around low-order streams at the highest elevations in these areas.

Material examined. Holotype: USA. North Carolina : Black Mts. 26-v, N. Banks coll., 1 male ( AMNH).

Non-type material. USA. North Carolina : Buncombe County, Seep uphill of Blue Ridge Parkway , by hand, 1225 masl, J. Robinson and C.R. Parker coll., 2-v-2007, 1 pupa ( BLRI 23487 ). 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., 6–13-vii -2013, 3 males, 4 females ( CUAC0000107304 ). 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., 6–22-vii-2019, 1 male ( CUAC000093253 ). Swain County, Beetree Ridge . GSM, K. Watson coll., 7-vi-1989, 2 males (one specimen missing genitalia), ( ECC 3.264 ). Transylvania County, Devil̍s Courthouse at Blue Ridge Parkway , J.K. Moulton coll., 17-viii -2005, 3 larvae ( FAMU). Watauga County, Spring seep below spring house , Moses H. Cone Estate , 1146 masl, J. Robinson and C.R. Parker coll., 29-iii-2007, 5 larvae ( BLRI 21955 ). Tennessee: Blount County, Great Smoky Mountains National Park, Cades Cove , Wildcat Branch of Abrams Creek , D. Etnier coll., 16–18-vii-2017, 1 male ( ECC 3.735 ). Fentress County, Cave Creek, Tributary of Pogue Creek , at end of ATV road off Williams Cr. Rd , 0.5 km east of Delk Cr. Rd., D. Etnier et al. coll., 21-v-2005, 1 metamorphotype male pupa, 2 larvae ( ECC 3.431 ). Sevier County, Great Smoky Mountains National Park , Twin Creeks Research Center , Cherokee , Orchard Rd ., Malaise trap, A.J. Mayor et al. coll., 2-vii-2004, 1 male ( ECC 3.760 ). Virginia: Augusta County, Spring at Dripping Rock pullout at MP 009.7 , left, by hand, J. Robinson and C.R. Parker coll., 17-vii-2007, 1 larva ( BLRI 25619 ). Bedford County, outflow Abbot Lake in Peaks of Otter Picnic Area , upstream entrance road , 730 masl, M. Geraghty and C.R. Parker coll., 9-vi-2006, 3 males ( BLRI 22764 ). Grayson County, Rivulet crossing at Meadow Beach Rd ., ex CR 634, 783 masl, [N36°37′11.22″, W81°02′ 57.80″], J.K. Moulton coll., 2v-2005, 1 male ( FAMU) .

Figures

Figure 11. Polycentropus carolinensis Banks,1905, male genitalia (holotype). A. left lateral (with phallus removed). B, dorsal. C, segment IX and inferior appendages, ventral. D, phallus, left lateral. E, dorsobasal process of right inferior appendage, caudal.

Figure 12. Polycentropus carolinensis Banks, 1905, female genitalia. A. left lateral. B, ventral.

Figure 40. Known Canadian province and US state distribution of Polycentropus carolinensis Banks, 1905, as indicated by grey shading.