Polycentropus blicklei Ross and Yamamoto, 1965

Orfinger, Alexander Benjamin, 2023, Taxonomic revision of the Polycentropus confusus species group (Trichoptera: Polycentropodidae), Journal of Natural History 57 (41 - 44), pp. 1825-1916 : 1837-1841

Polycentropus blicklei Ross and Yamamoto

( Figures 7–8 , 38 )

Polycentropus blicklei Ross and Yamamoto, 1965, p. 243 , fig. 5, J; type locality ′ Plymouth, New Hampshire ̍ ( INHS) .

Polycentropus blicklei Marshall and Larson, 1982: 22–24 , fig. 49, J.

Polycentropus blicklei Nimmo, 1986: 195 , figs. 111–114, J; figs. 115–116, ♀.

Polycentropus blicklei Armitage and Hamilton, 1990 : figs. A–B, D, J; figs. E–F, ♀.

Polycentropus blicklei Hoffman and Morse, 1990: 276–277 , figs. 1–4, ♀.

Diagnosis. Males of Polycentropus blicklei are most similar to those of P. aileenae , P. chenoides , P. elarus and P. maculatus . From females of P. aileenae , those of P. blicklei can be distinguished by the only slightly incurvate apices of the dorsal processes of the body of the pre-anal appendage, vs the strongly inflected dorsal processes of the bodies of the pre-anal appendages in P. aileenae . In ventral view, the ventral portions of the inferior appendages are evenly tapered in P. blicklei , vs having basal half wide and distal half abruptly tapered and inner margin curved outward in P. aileenae and P. elarus . Males of P. blicklei differ from P. chenoides by the erect dorsobasal processes of the inferior appendage and the slight ventral curvature of the intermediate appendages, vs the deflexed dorsobasal processes of the inferior appendages and the intermediate appendages curved strongly dorsad in P. chenoides . From P. maculatus , P. blicklei is readily distinguished by the shape of its ventral portions of the inferior appendage in ventral view evenly tapered to a round apex vs the blade-like shape seen in P. maculatus , and the phallus curved only slightly ventrad beyond mid-length in P. blicklei , vs curved roughly 90° ventrad beyond mid-length in P. maculatus .

Females of P. blicklei are most similar to those of P. aileenae . The internal parts of gonopods VIII are acute at the posterior apices and blade-like in P. blicklei , vs round at the apices and semi-elliptical in P. aileenae . In addition, the posterior apices of the ventral plates of P. blicklei are round in lateral view, vs acute in P. aileenae . In ventral view, the ventral plates are convergent only beyond about ¾ length in P. blicklei , vs those of P. blicklei which are convergent along the length of the ventral plates.

Adult description

General. Length. of male 5.5–7.1 mm (mean = 6.5 mm; n = 9). Length of female 5.8– 9.0 mm (mean = 7.7 mm; n = 5).

Male genitalia ( Figure 7A–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 slightly ventrad, their apices each bearing 4 small setae; in dorsal view apices proximate, parallel. Bodies of pre-anal appendages each with triangular posteroventral process with sinuous margins; dorsal process long, curved ventrad, variably terminating above corresponding posteroventral process of body of pre-anal appendage to extending to head of basodorsal process of corresponding inferior appendage, acute apically; in dorsal view slender, elongate, sinuous, subparallel, incurvate apically. Inferior appendages in lateral view each with capitate basodorsal process erect with moderately long neck and subtriangular head round dorsally, projecting ventrad with anteroventral margin rugose, apex pointed, visible above main body of appendage, main body of appendage with dorsal and ventral margins subparallel along length, subacuminate, apex extended posterad beyond intermediate appendages; in ventral view subparallel, wide basally, distally tapering to round apex, basodorsal process partially hidden by main body of inferior appendage, lateral margins extending beyond lateral margins of each main body of appendage, in cleared specimen broad, with medial pointed projection; in caudal view with wide base and oblong, round medial projection. Phallus a fully sclerotised tube, in lateral view with larger base, curved slightly ventrad beyond mid-length, apical section subrectangular, internal spinules absent, internal phallic sclerite short, oriented dorsoposterad, with round ventral base and tapered, acute dorsal vertex.

Female genitalia ( Figure 8A–B ). Venter VIII in ventral view with ventral plates subparallel for ¾ length, then convergent for final ¼ length, base broad tapering beyond ¾ length to round apex, 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 posterad beyond ventral plates in round process; internal parts of gonopods VIII in ventral view visible through venter VIII even in uncleared specimen, appearing longitudinally wrinkled, darker than surrounding tissue, subparallel, blade-like, with acute posterior apices distinctly anterior of apices of ventral plates, lateral margins incurvate beyond mid-length; in ventral view anterior part of genital chamber sclerotised, semicircular; processus spermathecae subovoid with central elevation bearing opening of ductus spermathecae.

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

Pupa. Unknown.

Notes. The figure labelled as depicting the dorsal view of the male genitalia of P. blicklei included in the species treatment of P. blicklei by Armitage and Hamilton (1990) (Figure C) is incorrect. In fact, the figure is the dorsal view of the male genitalia of Polycentropus barri Ross and Yamamoto, 1965 , reproduced from Ross and Yamamoto (1965).

Biology. Nimmo (1986) states that this species is found in both standing and flowing waters. I have observed no evidence of lentic examples of the species, and it appears that P. blicklei occurs only in flowing, relatively cool waters of various substrates including cobble and sand with benthic deadwood. The single male taken from Illinois was collected adjacent to a wetland with both flowing and still waters, and close to the Vermillion River. It seems most likely based on the record data that the specimen emerged from one of the many lotic habitats in the area. Adults have been collected from March to September, emerging earliest at lower latitudes. The only known larvae are late-instar larvae collected in Maryland in early April.

Distribution ( Figure 38 ). Canada: New Brunswick, Nova Scotia, Newfoundland and Labrador, Ontario, Quebec; USA: Alabama, Delaware, Florida, Georgia, Illinois *, Kentucky, Maine, Maryland, Mississippi, North Carolina , New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, South Carolina , Tennessee, Virginia.

There are several instances of states without records of P. blicklei despite being partially or completely surrounded by states or provinces with verified records of the species. These are Connecticut, Indiana, Massachusetts, Michigan, Vermont, West Virginia. It is possible that P. blicklei will be found from many or all of these areas, even those that have been well studied such as Michigan. For example, Ross and Yamamoto (1965) described P. blicklei and recorded it from several states. Despite this, it is only in the present study that it has been reported from Illinois, a well-studied state in which both Ross and Yamamoto were based and surveyed extensively. These new record data raise the possibility that improved environmental conditions, eg resulting from the Clean Water Act and other legislation, have allowed the arrival or return of P. blicklei in Illinois. Alternatively, this species may have just been missed in previous surveys, or, less likely, could have arrived by other means (e.g. human-mediated translocation).

Ross and Yamamoto (1965) hypothesised based on the records available at the time that this is a predominantly north-eastern species, despite the single paratype specimen recorded from Wall Doxey State Park in northern Mississippi. The authors suggested that this specimen represents a relict population that may have reached the area during cooler periods of the Pleistocene, as evidenced by the cool, fast-flowing stream from which the specimen was taken. Based on the numerous records now available, some as far south as Alachua County in north-central Florida, it is evident that this species is widespread and common throughout the eastern Nearctic Region.

Material examined. Holotype: USA. New Hampshire: Grafton County, Plymouth , R.L. Blickle and W.J. Morse coll., 6-viii-1947, 1 male ( INHS Insect Collection 38,134) . Paratypes: USA. Mississippi: Marshall County, Holly Springs, Wall Doxey State Park , At Light, Ross and Stannard coll., 21-v-1957, 1 male ( INHS Insect Collection 38,133) . New Hampshire: Strafford County, Lee, W.J. Morse coll., 7-vii-1951, 1 male ( INHS Trichoptera 24,563) .

Non-type material. Canada. New Brunswick: Exmoor , [N46°58 ʹ 15.60″, W65°51 ʹ 10.80″], KSH and RB coll., 2 vi-2008, 1 female (08NBEPT-1611) . Ontario: Grey County, Fay Jensen Farm , grass field behind barn, UV light at sheet, 343 masl, [N44°22 ʹ 48.00″, W80°34 ʹ 48.00″], J.E. Cossey, N.W. Jeffery, and J.R. Straka coll., 21-vi-2008, 1 female (08ONCAD-0227) . USA. Alabama: Bibb County, Rocky Branch , S. Harris and S. Hamilton coll., 12-vi-1991, 1 male ( FAMU) . Franklin County, Dismal Wonders Garden, Dismal Branch , UV light, S.C. Harris coll., 2vi-1983, 1 male ( FAMU) . Morgan County, Hughes Creek , light trap, [N34°24 ʹ 38 ̍, W86° 37 ʹ 07 ̍], B. Dinkins coll., 19-ix-2020, 1 male ( FAMU) . Illinois: LaSalle County, Wetlands South of Iron Bridge , Lone Star Zone, M.A. Repiscak coll., 22-v-2021, 1 male ( INHS Insect Collection 932,314) new state record. Maryland: Anne Arundel County, SR-01-18, Sewell Spring Branch , [N39°04 ʹ 34.93″, W76°37 ʹ 05.88″], M. Cole coll., 3-iv-2018, 3 larvae (Cole Ecological, Inc. 7670) . Mississippi: George County, 3 miles north of Lucedale, R. Kergosien coll., 19–31-iii-1996, 1 male (USNMENT01507913) , 1 male (USNMENT01507912) . 9–14-iv-1996, 1 female (USNMENT01507916), 1 female (USNMENT01507915), 1 male (USNMENT01507914) . New]ersey: Burlington County, Brendon T. Burns State Forest, Mt Misery, [N39°54 ʹ 58.09″, W74°30 ʹ 52.69″], S. Harris coll., 03- vii-2012, 1 male (FAMU) . Mt. Misery area , Mt. Misery Brook, 6.5 km East jct. Highway 70 and Highway 72, Malaise trap, 38 masl, [N39°55 ʹ 11″, W74°31 ʹ 24″], J. Gelhaus coll., v-30-vi-13- 1993, 4 males ( FAMU) . New York: Franklin County, Dutton Brook , Route 3 near Saranac Lake , L. Myers and B.C. Kondratieff coll., 27-vi-2007, 1 male ( BYU) . North Carolina : Transylvania County , S. Mills R. Tributary, US 376 at FS 1206, JLR coll., 12-vi-2008, 1 male ( ECC 3.516 ) . Pennsylvania: Upper Hedgehog Creek , S. Harris coll., vi-12,010, 1 male ( FAMU) . Tennessee: Jefferson County, Dumplin Creek at old TN Rt. 92, UV light trap, [N36°03 ʹ 38.83″, W83°27 ʹ 20.64″], J.K. Moulton coll., 26-v-2006, 1 female ( FAMU) . 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″], A. Orfinger and A. Perilla coll., 6-VI-2020, 2 males ( FAMU) . J.K. Moulton and A. Orfinger coll., 10-IV-2019, 1 male ( FAMU) .

Figures

Figure 7. Polycentropus blicklei Ross and Yamamoto, 1965, 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 8. Polycentropus blicklei Ross and Yamamoto, 1965, female genitalia. A. left lateral; B. ventral.

Figure 38. Known Canadian province and US state distribution of Polycentropus blicklei Ross and Yamamoto, 1965, as indicated by grey shading.