Riethia (Kieffer 1917) (Diptera: Chironomidae) revised for the Austro-Pacific region
Author
Cranston, Peter S.
text
Zootaxa
2019
2019-07-25
4646
3
461
500
journal article
25594
10.11646/zootaxa.4646.3.3
4a3d31ca-e16b-4ccf-8407-231aa27702f1
1175-5326
3351058
25CA4A18-955F-4EA7-8978-E93032B54A2E
Riethia cinctipes
Freeman
(
Figs. 2B
,
3E, 3J
,
4I
,
5A, E
,
6E
)
Riethia cinctipes
Freeman 1961
; Cranston 1966, 2000.
Riethia
Pe
‘Brisbane’ Cranston 1966, 2000
Type material.
Paratypes
,
♂
, pinned, separate hypopygium on celluloid mount, ‘
F.C.T. Blundells’
[
AUSTRALIA
,
Australian Capital Territory
,
Blundell’s Farm
]
18.2.1931
,
A.L.Tonnoir
[ANIC].
Riethia cinctipes
Freeman
det.
Freeman
1960 (2 labels)
;
♀
, pinned, ‘
Stanwell Pk’
[
New South Wales
],
2 Mar 23
[1923]
;
second label as
♂
above.
Other material
(collected Cranston, deposited ANIC, unless otherwise stated)
:
Queensland
,
2♂♂
,
1
♀
, McIlwraith Range,
15 km
WNW Bald Hill,
13°43’S
143°19’E
,
27.vi.–12.vii.1989
(
Naumann
, ANIC expedition)
;
1
♂
,
7 miles
N. Hope Vale Mission,
4.x.1980
(at light) (
Colless
) #2542
;
5
Pe
,
Emmagen Ck.
, 16°02.7”S 145°27.0”E, 9/
10.ix.1997
(
McKie
) #2068
;
2Pe, Mason Ck., 16°05.08”S 145°27.36”E,
23.iv.1999
;
3
Pe
,
Oliver Ck.
,16°08.3”S 145°26.7”E, 9/
10.ix.1997
(
McKie
) #2073,4, 7
Pe
,
23.–23.iv.1999
;
L, 6Pe, Mossman, Rex Ck.,
16°28’S
145°19’E
,
5–6.iv.1997
, #2543, 5
;
6
Pe
, same except
27–28.viii.1997
, #2546
;
6
Pe
, same except
17–18.xii.1997
, #2544
;
2L,
Le
/P
♂
,
Pe
,
19–20.x.1998
(
Cranston
&
Dimitriadis
) #2076-8
;
10
Pe
,
Mt. Lewis
, trib.
Churchill Ck.
,
16°34’S
145°20’E
,
6–7.iv.1997
, #2547-8
;
3
Pe
,
Clohesy R.
,
7–8.ix.1997
(
McKie
) #2067
;
5Pe, Mareeba, Davies Ck., above falls,
17°01’S
145°35’E
,
11–12.iv.1997
#2549
;
2
Pe
, same except
19–20.vi.1997
;
Pe
, same except
27–28.viii.1997
, #
2065-66
;
2
Pe
same except
17–18.xii.1997
, #2066
;
2
Pe
,
Kauri Ck.
,
11.vi.1997
(
McKie
) #2069
;
2
Pe
,
Mt. Haig
,?U.
Emerald Ck.
,
17°06’24”S
145°36’52”E
,
17–18.xii.1997
, #2550
;
Pe
,
Tinaroo
, unnamed
Ck.
,
17°09’S
145°37’E
,
11– 12.vi.1997
(
McKie
) #2075
;
4Pe, Bartle Frere, Junction Ck.,
17°16’S
145°55’E
,
1–4.iv.1997
, #2553
;
Pe
, same except
27–28.viii.1997
, #2551
;
5
Pe
, same except
17–18.xii.1997
,, #2552
;
2Pe, Herberton, Carrington Falls Ck.,
17°20’S
145°27’E
,
9–10.iv.1997
, #2554
;
Pe
,
Nigger Ck.
,
17°27’S
145°29’E
, #2555
;
P
♂
, 8
Pe
,
Palmerston N.P.
,
Learmouth Ck.
,
17°35’S
145°42’E
, #2062, -2556
;
Tchooratippa Ck.
,
17°37’S
145°45’E
,
8–9.iv.1997
, #2557
;
2
Pe
,
Python Ck.
,
17°46.2’S
145°35.4’E
,
2–3.xi.1997
(
McKie
) #2072
;
Pixies Ck.
,
2–3.ix.1997
,
17°47’S
145°41’E
(
McKie
), #2070-1
;
Le
/
Pe
/
♂
, 2
Le
/
Pe
/
♀
, nr
Cardwell
, 5-mile
Ck.
,
17.xii.1997
,
18°19’S
146°02.55’E
, #2064
;
L, same except 17.xiii.1997
;
Le
/
Pe
/
♀
,
Paluma
,
Birthday Ck.
,
18°58’S
146°09’E
,
24.x.1998
(
McKie
)
;
3
Pe
,
Paluma
, unnamed
Ck. S. Paluma
,
25–26.iii.1998
, #2558
;
Le
/
Pe
/
♀
,
Paluma
,
Camp Ck.
,
18°68’S
146°09’E
,
5.v.1999
(
Dimitriadis
)
;
Le
/P
♂
,
Yaccobine Ck.
,
17.v.1988
(
Edward
), #2061
;
2Pe, N.W. Brisbane, Bundaroo Ck.,
26°42’S
152°34’E
,
27.ix.1989
, #2559.
New South Wales
: 5
Pe
,
Chaelundi N.P.
,
Chandlers Ck.
,
30°02.22’S
152°29.26’E
,
11.iv.1996
, #2560
;
9
Pe
, nr
Dorrigo
,
Eve Ck.
,
30°16’S
152°50’E
,
9.x.1996
, #2056
;
2
Pe
,
Barren Ground N.P.
,
Redback Stream
,
34°40’S
150°44’E
,
9.iv.1994
, #2055
;
Pe
,
Endrick R.
,
6 km
NE Nerriga
,
35°05’S
150°08’E
,
1.ix.1988
, #2053;
Pe
/
♂
,
Rutherford Ck.
,
11.xi.1961
(
Brundin
) (
ZSM
)
.
Australian Capital Territory
(
ACT
): Pe, Brindabellas,
Lees Ck.
,
35°22’S
148°50’E
,
12–13.i.1998
(
Willis
&
Cranston
) #2058
;
same except
24.i.1998
(
Willis
) #2057.
Northern Territory
:
4
♂
,
Pe
,
Kakadu N.P.
,
Radon Spring
,
12°45’S
132°55’E
,
13–14.iv.1989
, #2051
;
2Pe,
Litchfield N.P.
,
Wongi Falls
,
13°10’S
130°41’E
,
6.viii.1990
, #2054.
Victoria
: L., nr
Anglesea
,
Angahook Forest
, AV
#82.1,
19.iii.1972
(
Martin
)
.
Molecular (
MV
) larvae.
Queensland
, 2L, Emerald Ck.,
16°58.50’S
145°34.00’E
,
8.ix.
2007
, 360 m a.s.l. (
Krosch
) (
MV
FNQDE
1R, DE1.24)
;
L, Atherton, Nigger Ck.,
17°26’S
145°28’E
,
1.ix.2005
(
Krosch
) (
MVN
7)
;
2L, Paluma, Birthday Ck.,
18°58.35’S
146°09.26’E
,
24.ix.
2008
, 700 m a.s.l. (
Krosch
) (
MV
FNQBC
8R1-2
)
;
L, Paluma, Little Birthday Ck./ Camp Ck.,
18°58’22”S
146°09’52”E
,
850 m
a.s.l.,
21.ix.2008
(
Krosch
) (
MV
FNQC- C4R1
)
;
L(
3i
) same except
22.ix.2008
(
MV
FNQBC
7R1
), L, same except
21.ix.2008
(
MV
PAa2
,
15
)
;
2L, Cloudy Ck.,
18°59.50’S
146°12.30’E
,
25.ix.
2008
, 720 m a.s.l. (
Krosch
) (
MV
FNQCCR
1
, 2,3)
;.
3L, Cooloola N.P., Frankis Gulch,
26°02.50’S
153°04.44’E
,
18.iv.2009
(
Krosch
) (
MV
AU09FG3, 4
, 10)
.
Northern Territory
, 4L, Kakadu N.P., Burdulba Ck.,
5.i.2007
(Hanley
et al
.) (
MV
NT
11B1R1-4, all
3i
) [possibly unknown larva of
R. kakadu
].
Description. Male.
Thorax yellow, with distinct brown vittae (dark area may be restricted to anterior of median vitta and lateral edges of lateral vittae) and transverse pleural stripe. Legs with dark band on mid-femur, femoral apex, base, mid and apex of all tibia, apices of all tarsomeres (
5th may
be all dark). Wing membrane infuscate, with transverse dark patch including both ‘forks’. Abdomen with posterior third of tergite II with dark transverse band; all succeeding segments with dark postero-lateral areas, genitalia brown. Setae of TIX long, slender, arranged in two clusters, separated medially by non-setose strip. Gonostylus relatively short, not tapered at gonocoxite junction, bearing essentially simple setae, some with fine branches, all distally pointed. Superior volsella (
Fig. 2B
) without microtrichia in basal or medial area, proximo-laterally with 4–6 long setae, without posterior projection, medially-directed lobe-shaped digitus without microtrichia, with 7–12 simple seta, ending in narrowed lobe or notched; inferior volsella small, mainly appressed to inner contour of gonocoxite and linked to superior volsella, without pectinate scales, with long simple setae and dense microtrichiae extending from distal area linking to superior volsella. Pseudovolsella no more than weak bulge with strong setae not differentiated from linearly aligned on inner gonocoxite (
Fig. 2B
). Mensural features as in
Table 1
.
Female
(n=3, part teneral). Colour similar to male, yellow with median vitta anteriorly brown oval, lateral vittae pale brown with darker outline anteriorly and laterally, extending from mid-scutum to just anterior to pale scutellum; central postnotum brown. anepisternum with broad brown linear ‘smear’. Wing with infuscate band over cross-veins, paler apically and at base. Legs with transverse band at 2/3 on forefemora, dark brown at distal apices of femora and proximal base of tibia (‘knees’); tibial apices darkened near spurs; apices of tarsomeres brown; foreleg with darkest pigment, mid and hind legs less intense. B.l. 6.0 mm, W.l.
2.5 mm
. Antenna flagellomeres 140–180, 105–115, 100–105, 95–100, 140–165; AR 0.32–0.34. 38–40 clyp, 16 multiserial orbitals. Palpomeres 50, 50–55, 170–300, 180–280, 260–360. Thorax. Ac?7–9, Dc 14, Pa 2–3, Scts 14–15. Wing V.R. 1.12. Vein setation: R 28–37, R
1
24–34
, R
4+5
58–67; sq. 11–19. Leg lengths: P
1
1400, 1440, 1440, 800, 640, 480, 220; P
2
1560, 1380, 780, 440, 320, 200, 110; P
3
1400, 1380, 940, 600, 420, 240, 120. Ratios: LR
1
1.01, LR
2
0.56, LR
3
0.68;, BV
1
2.04, BV
2
3.4, BV
3
2.7; SV
1
1.97, SV
2
3.77, SV
3
2.96. Foretibial comb, 50 with 5–6 lateral teeth each side; midtibials 65, 75, rear 65, 70, with strongly developed lateral teeth.
Pupa
. Brown with dark dorsal thorax, anterior wing sheaths and lateral apophyses on all abdominal segments; comb brown-black. Cephalothorax with strong frontal warts, thorax rugose with multiserial rows of dark tubercles on dorsum. Hook row on II continuous [one exception, see remarks], occupying c 50% of tergite width. Conjunctival spinule bands on III–V narrowly separated to almost completely contiguous with posterior tergal armament, on V narrower and maybe medially sparse. Pedes spurii B absent, vortex strong.Abdomen (
Fig. 3E
): Tergite II with triangular area of spinules anterior to and narrower than hookrow, without any more anterior spinules, TIII–V largely infilled with spinules, TVI with anterior-median oval area, separated from posterior transverse band; TVII and VIII with anterior and posterior areas of fine spinules. Comb (
Fig. 3J
,
4I
) variable, often with “windows” of pale cuticle within, with 1 strong, inner spine directed postero-medially and 3–4 subordinate spines.
Larva
. Head capsule yellow including postmentum and genae, with dark occipital margin, mandible golden yellow, bases of inner 4 mandibular teeth and mental teeth golden-brown. Clypeus lozenge-shaped, elongate-ovoid, 3× as wide as long (
Fig. 5A
,
6E
). Antenna (
Fig. 5E
) with 3
rd
segment longer than 2
nd
, characteristically narrowed basally and with thin wall on one side; segment 4 <2/3rds length of segment 2 (14–18μ to 21–25μ). Ventromental plate variable, with specimens from Cloudy Ck 20% longer than mentum width, with all others close to 100%. Mensural features as in
Table 2
.
Diagnosis.
Adults of
R. cinctipes
have distinctively ‘banded’ legs and pigmented wings, but both vary in intensity perhaps associated with tenerality. Amongst the males of the 5 taxa with patterned-legs, geographic distribution and male genitalia provide discriminatory features.
Riethia cinctipes
is an eastern Australian species as is
R. stictoptera
, the others are from Western Australia or
New Caledonia
. The characteristic gonostylus of
R. stictoptera
differs from the conventional one of
R. cinctipes
. The digitiform appendage of the superior volsella, absent in
R. stictoptera
, differs in each of the other banded-leg species, see key and
Figures 2B, 2C, 2G
. Specifically, the medially-directed digitus has a notch or apical tooth on the anterior margin in
R. cinctipes
whereas the digitus tapers evenly to a point in
R. donedwardi
.
The pupa of
R. cinctipes
also resembles that of
R. stictoptera
with undivided hookrow and only conjunctives III and IV with continuous rows of spinules and with sparse spinules on the posterior of TII. The pupa of
R. cinctipes
lacks pedes spurii B and tergite II has a moderate-sized spinule area, about as wide as the hook row, in contrast to a smaller spinulose area in
R. stictoptera
.
Some southern exuviae and those from N.T. have the conjunctival bands more distinctly separated from the tergal spinulation. None of these are reared, and for the present they are treated as variants of
R. cinctipes
.
Larvae of
R. cinctipes
have a low AR (<1.2) as does
R. donedwardi
, but the mentum and inner mandibular teeth are brown compared to the yellow-gold teeth in
R. donedwardi
which is a species restricted to
Western Australia
. The 3
rd
antennal segment is much longer than the 2
nd
but is subequal in
R. donedwardi
and also is narrowed, seemingly thinner-walled, medially (
Fig. 5E
). Further differentiation comes from the lozenge-shaped (elongate-ovoid) clypeus, 3× as wide as long.
Remarks.
There is substantial variation in the setosity of the male thorax. For example, a reared male from 5- mile Creek has multiple rows of dorsocentrals, but unreared males from further north in
Queensland
have fewer near uniserially arranged. The ventromental plate with respect to the width of the mentum falls in to two classes: close to equal (ratio=1.0) or greater (ratio = 1.2 for same width of mentum). This partially conforms to variation seen in molecular barcode patterns—unfortunately only
1 specimen
produced 4 genes.
DIstribution and ecology.
R. cinctipes
is an eastern Australian species with a range extending from
13°S
-
14°S
in Kakadu and Litchfield National Parks,
Northern Territory
and north
Queensland
, southwards to an isolated record from south coastal
Victoria
. Most reports are from the north to central parts of this range, with no specimens from
Tasmania
. Most sites are from running waters, but this habitat is over-represented due to use of drift nets in lotic conditions. Larvae do occur in billabongs and standing waters in rivers, usually with good to excellent water quality.