Taxonomic revision of the Polycentropus confusus species group (Trichoptera: Polycentropodidae)
Author
Orfinger, Alexander Benjamin
Department of Life Science, Dalton State College, Dalton, GA, USA; bCenter for Water Resources, Florida A & M University, Tallahassee, FL, USA; cDepartment of Entomology and Nematology, University of Florida, Gainesville, FL, USA
aorfinger@daltonstate.edu
text
Journal of Natural History
2023
2023-11-30
57
41 - 44
1825
1916
http://dx.doi.org/10.1080/00222933.2023.2271609
journal article
10.1080/00222933.2023.2271609
1464-5262
10492470
Polycentropus elarus
Ross
(
Figures 21–22
,
46
)
Polycentropus elarus
Ross, 1944: 666
, fig. 245, J; fig.
256,
♀
;
type
locality ′
Costello Lake
,
Algonquin Park
,
Ontario
̍ (
INHS
, lost)
.
Polycentropus elarus
Nimmo, 1986: 197
, figs. 140–144, J; figs. 145–146,
♀
.
Polycentropus elarus
Armitage and Hamilton, 1990
: figs. A–D, J; figs. E–F,
♀
.
Diagnosis.
Males of
Polycentropus elarus
are most similar to those of
P. aileenae
and
P. stephani
in the ventral aspect of the ventral portions of the inferior appendages and to
P. aileenae
also in the size and shape of the head of the basodorsal processes of the inferior appendages. From these and other males of species in the group,
P. elarus
can be distinguished by the dorsal processes of each pre-anal appendage being directed caudad and slightly curved dorsad and convergent apically. From males of
P. aileenae
, those of
P. elarus
are distinguished by the shorter basodorsal processes and ventral portions of the inferior appendages and by the subparallel rather than divergent ventral portions of the inferior appendages. From males of
P. stephani
, males of
P. elarus
are identified by the capitate head of the basodorsal process of the inferior appendage and by the lack of a basoventral spur on the phallus. From all other species, males of
P. elarus
are distinguished by the size and shape of the small, round heads of the basodorsal processes of the inferior appendages and by the shape of the ventral portions of the inferior appendages as seen in ventral view.
Females of
P. elarus
are distinguished from female of all other members of the
Polycentropus confusus
species group by the combination of the posterior apex of external parts of gonopods VIII in lateral view being slender, almost digitiform, and either oriented caudad or recurved dorsad and the anterior part of the genital chamber sclerotised, being U-shaped and appearing connected to the smooth internal parts of gonopods VIII that are curved about 90° laterad to apices of ventral plates distally.
Adult description
General
. Length.
of male 6.0–
8.5 mm
(mean =
7.2 mm
; n = 6). Length of female
8.6– 9.5 mm
(mean = 9.0 mm; n = 5).
Male genitalia
(
Figure 21A–E
).
Abdominal segment VIII annular. Terga IX and X fused, membranous, extended caudad over bases of intermediate appendages. Sternum IX subovoid in lateral view. Intermediate appendages originating beneath terga IX+X and extending beyond them, oriented caudad, their apices each bearing 4 small setae; in dorsal view apices proximate, subparallel to divergent. Bodies of pre-anal appendages each with small, round subtriangular posteroventral process with subtle ventral emargination; dorsal processes long, each curved ventrad for 2/3 length, curved slightly dorsad for final 1/3 length, extending only to dorsal portion of body of pre-anal appendage, acute apically; in dorsal view stocky, elongate, subparallel for nearly entire length, convergent apically. Inferior appendages in lateral view each with capitate basodorsal process erect with moderately long neck and small head round dorsally and projecting ventrad with its round, subtriangular apex visible above main body of appendage, main body of appendage with broad base, dorsal and ventral margins tapering evenly to round apex extended posterad slightly beyond intermediate appendages; in ventral view subparallel, wide basally, margins subparallel for ½ length, inner margin curved abruptly outward beyond ½ length to narrow round apex, basodorsal process completely hidden by main body of inferior appendage, in cleared specimen small, with medial round projection; in caudal view oblong, with medial projection round. Phallus a fully sclerotised tube, in lateral view with larger base, curved about 20° ventrad slightly beyond mid-length, apical section slightly enlarged, subrectangular, posterior margin slightly sinuous with ventral lip, with internal spinules absent, internal phallic sclerite long, horizontal, with round slender, acute anterior base and wide subrectangular posterior apex.
Female genitalia
(
Figure 22A–B
).
Venter VIII in ventral view with ventral plates convergent, narrow, semi-elliptical, tapering apically, covered with setae; in lateral view each narrow at base, wide at mid-length, ventral margin sinuous beyond mid-length, narrowing to 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 projected caudad to recurved dorsad; internal parts of gonopods VIII in ventral view visible through venter VIII even in uncleared specimen, appearing smooth, darker than surrounding tissue, subparallel basally for 4/5 length, curved about 90° laterad to apices of ventral plates distally, sinuous along length, tapering gradually to apex, anterior ends appearing connected to anterior part of genital chamber at sclerotised external part of gonopods VIII at basal third of ventral plates; in ventral view anterior part of genital chamber sclerotised, U-shaped, strongly sinuous, wrapping around posterior apex of processus spermathecae; processus spermathecae large, subovoid with central elevation bearing opening of ductus spermathecae.
Figure 21.
Polycentropus elarus
Ross, 1944
, male genitalia (neotype). 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 22.
Polycentropus elarus
Ross, 1944
, female genitalia. A, left lateral. B, ventral.
Larva.
Described by
Orfinger
et al
. (2023)
.
Pupa.
Unknown.
Notes.
The
holotype
is listed by
Ross (1944)
as deposited at INHS but could not be located and is presumed lost. INHS Insect Collection 37255 specimen designated as
neotype
.
Biology.
Adults of this fairly common species is found near cool, clear, flowing streams of with various substrates depending on locality. Adults have been collected from April to September, sometimes in abundance. The single known late-instar larva was collected in June from an unimpaired (
Bott
et al
. 2012
), small, cool, fast-flowing stream with rocky substrate.
Distribution
(
Figure 46
).
Canada
:
Ontario
,
Quebec
;
USA
:
Alabama
,
Florida
,
Georgia
,
Illinois
*,
Indiana
,
Kentucky
,
Massachusetts
,
New Hampshire
,
New York
,
North
Carolina
,
Ohio
,
Pennsylvania
,
Tennessee
,
Virginia
,
West Virginia
.
This
species is widespread in the eastern
United States
and
Canada
. It is likely that this species will be encountered in additional states and provinces neighbouring areas from which it has been taken.
For
example,
Orfinger and Moulton (2021)
recently reported the species from the
Florida
panhandle based on a single male specimen, and is reported herein for the first time from
Illinois
based on
five male
specimens. Similarly, it would be unsurprising if
P.
elarus
was eventually recorded from
Mississippi
,
Michigan
,
South
Carolina
,
Maryland
,
New Jersey
,
Vermont
,
Maine
,
Delaware
,
Connecticut
,
Rhode Island
, and
New Brunswick
.
Material examined.
Neotype
:
Canada
.
Ontario
: Algonquin Park,
Ontario Fish Research Lab
,
Costello Lake
,
Cage No.
1,
W.M. Sprules
coll.,
11-vi-1939
,
1 male
(
INHS
Insect Collection 37,255)
.
Paratype
:
USA
.
New York
: Adirondack Park,
Bear Brook near Blue Mountain Lake
,
Frison
and
Ross
coll.,
19-vi-1941
,
1 male
(
INHS
Trichoptera
24,573)
.
Allotype
:
Canada
.
Ontario
: Algonquin Park,
Ontario Fish Research Lab
,
Costello Lake
,
Cage No.
1,
W.M. Sprules
coll.,
22-vi-1939
,
1 female
(
INHS
Insect Collection 37,262)
.
Non-type material:
Canada
.
Ontario
:
Algonquin Provincial Park
,
Costello Lake
,
Ontario Fisheries Research Laboratory
,
W.M. Sprules
coll.,
22-vi-1939
,
1 female
(recorded by Ross as male) (
INHS
Trichoptera
54,986)
.
USA
.
Alabama
:
Dekalb County
,
Fort Payne
,
Straight Creek
, UV light trap,
468 masl
, [
N34°38
ʹ
34.98″
,
W85°36
ʹ
41.52″
],
A. Orfinger
and
A. Perilla
coll.,
27–28-vi-2020
,
116 males
(
FAMU
)
.
Florida
:
Washington
County
, Econfina Creek Water Management Area,
Unnamed ravine stream (lower reach) that flows into Whitewater Lake
off Porter Pond Rd., [
N30°28
ʹ
46″
W85°33
ʹ
14″
],
Rasmussen et al.
coll.,
6-vi-2009
,
1 male
(
FAMU
)
.
Illinois
:
Ford County
,
Paxton Railroad Prairie
, light,
229 masl
, [
N40°25
ʹ
08.33″
,
W88°06
ʹ
51.70″
],
J.D. Unzicker
coll.,
7-vi-1962
,
3 males
(
INHS
Insect Collection
38,151)
new state record
.
Pope County
,
Simmons Creek
, War Bluff
Valley Audobon Society Sanctuary
,
8.7 km
N Golconda
,
black light trap
, [
N37°26
ʹ
43.84″
,
W88° 29
ʹ
19.64″
],
J.L. Robinson
coll.,
29-viii-2015
,
2 males
(
INHS
Insect Collection
797,581)
new state record
.
Indiana
:
Montgomery County
,
Shades SP
,
Crystal Falls Stream
,
L. Chandler
and
R. Smith
coll.,
12-v-1963
,
1 female
(
INHS
Trichoptera
54,984)
.
Kentucky
:
Bell County
,
Martins Fork
,
Cumberland River
downstream of upper bog,
735 masl
,
M. Geraghty
and
C. Parker
coll.,
19-vii-2006
,
1 female
(
CUGA 4851
)
.
Pennsylvania
:
Schuylkill County
,
Rattling Run
, [
N40°35
ʹ
02.40″
,
W76°01
ʹ
01.20″
],
T. Bringloe
,
V. Harvey
,
S. Ripley
,
K. Rondollo
coll.,
13-vi-2013
,
1 larva
(
BIOUG07980
-
B
07)
.
Tennessee
:
Greene County
,
Tusculum College
, [
N36°10
ʹ
26.00″
,
W82°45
ʹ
39.99″
],
M. Wright
coll.,
23–30-v-1946
,
1 male
,
1 female
(
INHS
Trichoptera
54,983)
.
Virginia
:
George Washington National Forest
,
Passage Creek
, G. Washington Nat. For., For. Rt.
274, 396 masl
, [
38°43
ʹ
30″
,
W78°32
ʹ
24″
],
Blahnik
and
Contreras
coll.,
19-ix-1992
,
1 male
(
UMSP 000048997
)
.
West Virginia
:
Hardy County
,
3 miles
north-east of Mathias
, [
N38°33
ʹ
00.00″
,
W78°29
ʹ
24.00″
],
D. Smith
coll.,
27-vi -2007
,
1 male
(
BYU
)
.