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 alabamensis
Hamilton, Harris, and Lago
(
Figures 5–6
,
37
)
Polycentropus alabamensis
Hamilton, Harris, and Lago, 1990: 363–365
, fig.
1, J;
type
locality ′
United States
:
Alabama
:
Lawrence Bee Branch
below falls,
Bankhead National Forest
̍ (
USNM
, lost)
.
Polycentropus
new species
12 Hamilton 1986: 70–71, fig. 4.2, J.
Polycentropus
n. sp.
(nr.
elarus
)
Lago and Harris 1987: 258
.
Diagnosis.
Males of this species are most similar to those of
P. elarus
in the apical narrowing of the inferior appendages,the shape of the basodorsal process of the inferior appendage, the similar shape of the pre-anal appendages, and the sinuate curvature of the dorsal process of the pre-anal appendages.
Polycentropus alabamensis
can readily be distinguished from
P. elarus
and all other members of the
P. confusus
species group by the following combination of characters: prominent, acute, posteroventral point on each pre-anal appendage, the apicodorsal emargination forming a caudal spur visible on the dorsobasal process of each pre-anal appendage, the tapered, incurved apex of the intermediate appendages, and the tapered, strongly incurved apex of the inferior appendages in ventral view.
Females of
P. alabamensis
are distinguished from those of all other species in the
P. confusus
species group by reniform wrinkled interior parts of gonopods VIII, by the posterior apex of external parts of gonopods VIII with a deep mesal emargination and appearing bifid in ventral view, and by the unique shape of segment IX bearing bilateral acute, horn-like processes.
Adult description
General
. Length.
of male
6.9–7.8 mm
(mean =
7.3 mm
; n = 5). Length of female 8.2– 9.0 mm (mean =
8.5 mm
; n = 3).
Male genitalia
(
Figure 5A–E
).
Abdominal segment VIII annular. Abdominal sternite IX large, semicircular in lateral view, anterior margin round, posterior margin nearly straight; in ventral anterior margin deeply emarginate. Intermediate appendages originating beneath terga IX+X and extending beyond them, curved gradually caudoventrad, their apices each bearing 5 small setae; distally extending beyond tergum X, apices each bearing 5 small setae; in lateral view curved slightly ventrad; in dorsal view apices proximate, subparallel. Body of pre-anal appendages short, with prominent sharp point, posteroventral in lateral view; in lateral view dorsal process moderately sinuate, decurved basally, distally, with apicodorsal emargination forming caudal spur; in dorsal view slender, elongate, moderately sinuate, subparallel. Inferior appendages in lateral view each with elongate ventral portions, in lateral view tapering slightly to apex, extending to apex of intermediate appendage, in ventral view greatly tapered beyond mid-length with apex acute, strongly curved mesally; basodorsal process prominent, erect, in lateral view neck long and thin, enlarged apex goose-head shaped with acute ventrally directed point, in caudal view blunt projection projecting downward. Phallus in lateral view tubular, moderately decurved, broadened apically, basally, with mesoventral concavity, internal spinules absent; internal phallic sclerite in lateral aspect moderately long, enlarged slightly distally, with tapered anterior portion.
Figure 5.
Polycentropus alabamensis
Hamilton, Harris, and Lago, 1990
, 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.
Female genitalia
(
Figure 6A–B
).
Venter VIII in ventral view with ventral plates short, subparallel to subtly divergent, semi-elliptical, tapered, laterally recurved, 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 round with two apical lobes separated by deep mesal emargination; in lateral view extending posterad beyond ventral plates in round process; segment IX in ventral view with diagonal mesolateral emarginations forming acute horn-like processes, in lateral view produced caudodorsad, evenly tapered to acute apex extending beyond ventral plates; internal parts of gonopods VIII in ventral view visible through venter VIII even in uncleared specimen, appearing longitudinally wrinkled, darker than surrounding tissue, subparallel to subtly divergent, reniform, with acute posterior apices distinctly anterior of apices of ventral plates, caudolateral margins sinuous; in ventral view anterior part of genital chamber sclerotised, subtrapezoidal, base overlapping with sclerotised margin of segment IX; processus spermathecae subovoid with central elevation bearing opening of ductus spermathecae.
Figure 6.
Polycentropus alabamensis
Hamilton, Harris, and Lago, 1990
, female genitalia. A. left lateral; B. ventral.
Larva.
Described by
Orfinger
et al
. (2023)
.
Pupa.
Unknown.
Notes.
The type series is lost. Specimen USNMENT01819507 is herein designated as the
neotype
for
Polycentropus alabamensis
.
Biology.
This species is most commonly collected in small streams of the Cumberland Plateau physiographic region and occasionally from the Coastal Plain physiographic region. Adults have been collected using UV light traps from April to September and late-instar larvae taken from cool, clear, flowing streams with rocky substrate in April.
Distribution
(
Figure 37
).
USA
:
Alabama
.
Material examined.
Neotype
:
USA
.
Alabama
:
Fayette County
,
Little Tyro Creek
, [
N33° 35
ʹ
20.76″
,
W87°29
ʹ
47.04″
],
A. Orfinger
coll.,
3-v-2021
,
1 male
(USNMENT01819507)
.
Non-type
material:
USA
.
Alabama
:
Bibb County
,
Rocky Branch, S
.C
.
Harris
and S
. Hamilton coll
.,
12-vi-1991
,
1 male
(
FAMU
)
.
Rocky Branch
at
USGS
Gage
,
1 male
(
FAMU
)
.
Fayette County
,
Headwaters of Wallace Branch
,
UV
light, [
N33°38
ʹ
16.80″
,
W87°31
ʹ
40.80″
], A
.
Orfinger
coll
.,
4-iv-2022
,
5 males
(
FAMU
),
3 females
(
FAMU
)
.
Wallace Branch
at headwaters, [
N33° 37
ʹ
44.76″
,
W87°31
ʹ
15.96″
],
3-v-2021
,
3 males
(
FAMU
)
.
Franklin County
,
Dismal Wonders Garden
,
Dismal Branch, S
. Harris coll
.,
2 vi-1983
,
1 male
(
FAMU
)
.
Morgan County
,
Hughes Creek
,
light trap
, [
N34°24
ʹ
38
̍,
W86°37
ʹ
07
̍], B
.
Dinkins
coll
.,
19-ix-2020
,
2 males
(
FAMU
)
.
2 males
(
FAMU
)
.
Spring
outside of
Curry Cave
,
6-7-iv-2020
,
2 larvae
(
FAMU
)
.
Winston County
,
Bankhead National Forest
, small tributary of
West Sipsey Fork
, west side of river
100 m
downstream of CR-60 bridge,
9.5 miles
north of
Double Springs
,
UV-black light pan trap
, A
.K
. Rasmussen coll
.,
24-v-2003
,
1 male
(
FAMU
)
.