Polycentropus aileenae Orfinger and Moulton, 2021

Orfinger, Alexander Benjamin, 2023, Taxonomic revision of the Polycentropus confusus species group (Trichoptera: Polycentropodidae), Journal of Natural History 57 (41 - 44), pp. 1825-1916 : 1829-1833

Polycentropus aileenae Orfinger and Moulton

( Figures 1 ; 3–4 , 36 )

Polycentropus aileenae Orfinger and Moulton, 2021 , p. 35,359, fig. 1, habitus; fig. 2, J, fig. 3, ♀; eggs; type locality ′ Tennessee: Knox County, Fowler Spring Branch, first-order tributary to Beaver Creek , Bell Campground Road, 0.3 km N of jct . with W. Brushy Valley Drive, [N36° 02 ʹ 56.2 ̍, W84°04 ʹ 07.6″]̍ ( USNM) .

Polycentropus carlsoni Morse, 1971 – Moulton 2007: 209–210.

Diagnosis. The male genitalia of Polycentropus aileenae are most similar to those of males of P. blicklei , P. carlsoni , P. carolinensis , and P. elarus . Polycentropus aileenae can be distinguished from the above-mentioned species by the strongly inflected apices of the dorsal processes of the pre-anal appendages in dorsal view vs straighter dorsal processes in the other species, and the slightly recurved dorsum of the apex of the phallus in lateral view absent in other species. From P. blicklei , P. carlsoni , and P. carolinensis , P. aileenae differs in the shape of the ventral portion of each inferior appendage in which the lateral and ventral margins are nearly straight vs moderately curved in P. carolinensis and P. carlsoni , and by the long rectangular basal half that in ventral view narrows abruptly from middle to apex vs gradual narrowing along length in P. blicklei . Polycentropus aileenae differs in the shallower and more round body of each pre-anal appendage vs the more broadly produced and more acutely terminated body of each pre-anal appendage in P. blicklei , P. carolinensis and P. elarus .

Female genitalia of Polycentropus aileenae are most similar to those of P. blicklei , for which only subtle differences are apparent in distinguishing females of the two species. The internal parts of gonopods VIII are round at the posterior apices vs the sharper posterior apices resulting in each having a blade-like appearance in P. blicklei . In P. aileenae , the posterior apices of the ventral plates are acute in lateral view, vs round in P. blicklei . In ventral view, the ventral plates are convergent along the entire length, vs convergent only beyond about ¾ length in P. blicklei .

Adult description

General ( Figure 1 ). Length of male 6.1–7.0 mm (mean = 6.6 mm; n = 5). Length of female 7.5–8.8 mm (mean = 8.1 mm; n = 2).

Male genitalia ( Figure 3A–E ). Abdominal segment VIII annular. Segment IX tergum fused with segment X (IX+X), membranous, caudally extended as short, horn-like projection (hl.p.IX+X). Segment IX sternum (s.IX) ovoid in lateral view, posterior margin slightly sinuous. Intermediate appendages (int.app.) positioned beneath terga IX+X, distally extending beyond tergum X, apices each bearing 3 small setae; in lateral view curved slightly ventrad; in dorsal view apices proximate, subparallel. Body of pre-anal appendages (pre.app.) slightly produced, with small posteroventral lobate process; in lateral view dorsal process long, narrow, curved ventrad; in dorsal view slender, elongate, strongly inflected and converging apically. Inferior appendages (inf.app.) in lateral view each with ventral portion gradually tapered, extended posterad slightly beyond intermediate appendages, ventral margin nearly straight; in ventral view, basal half wide, distal half abruptly tapered, inner margin curved outward; basodorsal process (d.p.) in lateral view erect, with long neck terminating in short, round head projecting downward, in ventral view completely hidden by main body of inferior appendage, head round with medial projection, in caudal acute, projecting downward. Phallus in lateral view curved ventrad, apical section rectangular, dorsum of apex slightly recurvate (subtle in some specimens), internal spinules absent, internal phallic sclerite (ph.sc.) moderately elongate.

Female genitalia ( Figure 4A–B ). Venter VIII in ventral view with ventral plates (v.pl.) narrow, tapering apically, convergent, and round at posterior apices in ventral view, covered in setae; in lateral view similar but each terminating in more acute apex posterad; external parts of gonopods VIII with posterior (p.ap.e.gon.VIII) margin slightly triangular and round mesally in ventral view; in lateral view extending beyond ventral plates in round process (e.gon.VIII); internal parts of gonopods VIII (i.gon.VIII) in ventral view visible through venter VIII, appearing longitudinally wrinkled, darker than surrounding tissue, parallel, semi-elliptical with round posterior apices distinctly anterior of apices of ventral plates, anterior ends oblique, extending to sclerotised external part of gonopods VIII at basal third of ventral plates; in ventral view anterior part of genital chamber (g.ch.a) sclerotised, semicircular; processus spermathecae (pr.sp.) subovoid with central elevation bearing opening of ductus spermathecae (op.dt.sp.).

Larva. Unknown.

Pupa. Unknown.

Notes. This species has also been recorded in abundance from: Destiny Farm, State College, PA, small watercress-choked tributary to Slab Cabin Run, [N40°44 ʹ 57.9″, W77° 52 ʹ 14.84″], 341 m. The material was lost before collection deposition and is not formally included in this description. However, the existence of this second population suggests a much wider distribution of P. aileenae than is currently reported based on deposited material. Additionally, a specimen collected in Exmoor, New Brunswick, Canada, and housed at the University of Guelph Centre for Biodiversity Genomics, 08NBEPT-1627, is only 0.47% divergent at the barcoding region of COI from P. aileenae (A. Orfinger, unpublished data). This specimen likely represents P. aileenae , but it is missing its abdomen and therefore its identity cannot be confirmed. The eggs of this species were briefly described by Orfinger and Moulton (2021).

Biology. Little is known of the biology of P. aileenae . Adults of the species have been collected from May to October near small (<4 m wide), stenothermic streams with emergent aquatic macrophytes, often watercress, and with rocky and sandy substrates.

Distribution ( Figure 36 ). Canada: Nova Scotia; USA: Alabama *, Pennsylvania, Tennessee.

Material examined. Holotype: USA. Tennessee: Knox County, Fowler Spring Branch, first-order tributary to Beaver Creek , Bell Campground Rd. , 0.3 km N of jct. with W. Brushy Valley Dr., UV light trap, 277 m, [N36°02 ʹ 56.20″, W84°04 ʹ 07.60″], A. Orfinger and A. Perilla coll., 6-vi-2020, 1 male (USNMENT01445176) . Allotype: USA. Tennessee: Knox County, Fowler Spring Branch, first-order tributary to Beaver Creek , Bell Campground Rd. , 0.3 km N of jct. with W. Brushy Valley Dr., UV light trap, 277 mm, [N36°02 ʹ 56.20″, W84°04 ʹ 07.60″], J. K. Moulton coll., 9-x-2005, 1 female ( FAMU) . Paratypes: USA. Tennessee: Jefferson County, Dumplin Creek at Hebron Church Rd ., UV light trap, 337 masl, [N36°03 ʹ 38.83″, W83°27 ʹ 20.64″], J .K . Moulton coll ., 30-v-2006, 5 males ( INHS Insect Collection 923,903) . 9-viii-2006, 5 males ( FAMU) . Dumplin Creek at old TN Rt . 92, 23-v-2005, 1 female ( CUAC000107332 ) . Tributary of Holston River at Good Hope Church Road , 280 masl, [N36°09 ʹ 58.28″, W83°33 ʹ 49.70″], G . Curler coll ., 28-V-2005, 1 male ( ROME187177 ) . Knox County, Fowler Spring Branch, first-order tributary to Beaver Creek , Bell Campground Rd ., 0.3 km N of jct. with W. Brushy Valley Dr ., 277 masl, [N36°02 ʹ 56.20″, W84°04 ʹ 07.60″], J .K . Moulton coll ., 18-xi-2006, 1 male ( CUAC000107331 ) . 9-x-2005, 1 male (USNMENT01445177).

Non-type material. Canada. Nova Scotia: Cape Breton Highlands National Park, Clyburn Valley Road , near golf course, Malaise trap, 21 masl, [N46°39 ʹ 19.08″, W60° 25 ʹ 42.60″], CBHNP Staff coll ., 12-vii-2013, 1 male ( BIOUG09994 -A03) . USA. Alabama: Fayette County, Wallace Branch at headwaters, [N33°37 ʹ 44.76″, W87°31 ʹ 15.96″], A . Orfinger coll ., 3-v-2021, 2 males ( FAMU) new state record . Morgan County, Hughes Creek, B . Dinkins coll ., 19-ix-2020, 1 male ( FAMU) new state record .

Figures

Figure 1. Left lateral habitus of the male of Polycentropus aileenae Orfinger and Moulton, 2021. Reproduced from Orfinger and Moulton (2021).

Figure 3. Polycentropus aileenae Orfinger and Moulton, 2021, 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. Abbreviations: d.p. = dorsobasal process of a pre-anal appendage (paired); hl.p. = horn-like projection of the combined terga IX and X; inf.app. = inferior appendage (paired); int.app. = intermediate appendage (paired); IX+X = combined terga IX + X; pre.app. = pre-anal appendage (paired); s.IX = sternum IX.

Figure 4. Polycentropus aileenae Orfinger and Moulton, 2021, female genitalia. A. left lateral; B. ventral. Abbreviations: IX = segment IX; e. gon. VIII = external parts of gonopods VIII; g.ch.a. = anterior part of genital chamber;i.gon.VIII = internal parts of gonopods VIII; op.dt.sp. = opening of ductus spermathecae; p.ap.e.gon.VIII = posterior apex of external parts of gonopods VIII; pr.sp. = processus spermathecae; v.pl. = ventral plate.

Figure 36. Known Canadian province and US state distribution of Polycentropus aileenae Orfinger and Moulton, 2021, as indicated by grey shading.