Redescription of two little-known Palaearctic species of Pseudodiamesa Goetghebuer (Diptera: Chironomidae: Diamesinae)
Author
Makarchenko, Eugenyi A.
text
Zootaxa
2022
2022-01-24
5092
5
596
600
journal article
2445
10.11646/zootaxa.5092.5.8
420a82fa-b386-4d11-b773-82b05a301d74
1175-5326
5896559
E8351291-CB4C-43FD-9050-1E3DAE87A29F
Pseudodiamesa
(s. str.)
gorodkovi
Makarchenko
(
Figs. 1–5
)
Pseudodiamesa
(s. str.)
gorodkovi
Makarchenko, 1983: 1909
;
Ashe & O’Connor 2009: 304
.
Material examined.
Holotype
: adult male,
Russia
,
Karachay-Cherkess Republic
,
Caucasus Mountains
,
Teberda Nature Reserve
, alt.
1300 m
above sea level
,
17.III.1964
, leg.
K. Gorodkov.
Paratypes
:
4 adult
males, same data as holotype
;
1 adult
male, same data as holotype, except
25.XII.1959
, leg.
L. Arens.
Adult male
(n = 3).
Total length 6.1–7.0 mm. Wing length 5.8–6.0 mm. Total length/wing length 1.0–1.16.
Coloration. Head, thorax, legs, and abdomen dark brown to black; antennae brown to dark brown; wings greyish.
Head. Eyes bare and extended dorsomedially. Temporal setae including 14–16 preoculars, 8–14 verticals and 8–10 postorbitals. Clypeus with 41–48 setae. Antenna with 13 flagellomeres and developed plume, setae of which 525–1689 μm long; pedicel without setae; terminal flagellomere with 1 subapical setae 64–72 μm long; AR 3.96–4.40. Palpomere lengths (in μm): 44–50; 186–193; 294–300; 248–252; 280–290. Palpomere 3 distally with sensilla capitata (diameter 16–20 μm). Palpomeres 1–5 length/head width 1.01–1.11.
Thorax. Antepronotum with 20–22 lateral setae. Acrostichals absent, dorsocentrals 38–43 (in 2 rows in anterior 2/3 and in 3 rows in posterior 1/3), prealars 51–56 (in 2–3 rows), scutellars
ca
60–67.
Wing. Length 5.8–6.0 mm; width
1.40–1.44 mm
. Membrane without setae.
R
and
R
1
with 9–12 setae,
R
4+5
with 2 setae on apex. Costa extension 150–160 μm long.
RM
length/MCu length 2.0–2.3. Anal lobe developed, outline rounded.
Squama with
ca
80–90 setae, 164–197 μm long, in 2 rows. VR 0.90–0.91.
Legs. Spur of fore tibia 136–172 μm long; spurs of mid tibia 96–113 μm and 92–101 μm; of hind tibia 140–143 μm and 76–101 μm long. Hind tibial comb with 12–16 setae. Lengths and proportions of leg segments as in
Table 1
.
FIGURES 1–5.
Male of
Pseudodiamesa
(s. str.)
gorodkovi
Makarchenko.
1, 3,
hypopygium in dorsal view;
2,
gonostylus in dorsal view;
4,
gonostylus in ventral view;
5,
transverse sternapodeme, lateral aedeagal lobes and basal lobe of gonocoxite.
TABLE 1.
Lengths (in µm) and proportions of leg segments of
Pseudodiamesa
(s. str.)
gorodkovi
Makarchenko
, male (n=3).
fe |
ti |
ta 1 |
ta 2 |
ta 3 |
ta 4 |
ta 5 |
P1 |
1920–1924 |
2080–2160 |
1280–1300 |
728–760 |
494–520 |
312–360 234–240 |
P2 |
2080 |
2080–2160 |
858–1280 |
520–800 |
520 |
234–300 218–240 |
P3 |
2340–2480 |
2704–2760 |
1248–1320 |
780–840 |
520–780 |
300–312 200–260 |
continued. |
LR |
BV |
SV |
BR |
P1 |
0.59–0.63 |
2.66–3.00 |
3.00–3.19 |
3.0–4.9 |
P 2 |
0.41–0.59 |
2.97–3.78 |
4.46–4.85 |
2.1–2.2 |
P3 |
0.46–0.48 |
3.33–3.53 |
3.97–4.12 |
3.4–4.4 |
Hypopygium (
Figs. 1–5
). Tergite IX with 16–28 setae on each side, 56–68 μm long. Anal point wide in basal part, tapering to pointed apex, 168–170 μm long (
Figs. 1–3
). Laterosternite IX with 16–22 setae. Gonocoxite 520–525 μm long; basal lobe of small size, rounded, with some long setae at inner part (
Figs. 1, 3, 5
). Gonostylus 358–361 μm long, massive, in dorsal view with large lobe on the outer edge and with small triangular tubercle in the basal part along the inner edge (
Figs. 1–3
); shape in ventral view as in
Fig. 4
; apically with small tooth, megaseta absent. HR 1.45–1.63. Transverse sternapodeme 260 μm long and 96–100 μm wide, with short rod-like oral projections, anterior margin slightly concave (
Fig. 5
). Phallapodeme with lateral aedeagal lobe 184–192 μm long, which more wide in basal 1/4 and narrow in distal 3/4, elongated in rounded apex (
Fig. 5
).
Pupa
and
larva
unknown.
Remarks.
I include this species in the
nivosa
group. The original description (
Makarchenko 1983
) did not contain data on the shape and structure of the transverse sternapodeme. Namely, these characters are present only in
P.
(s. str.)
gorodkovi
and are absent in other representatives of the genus. Also, this species differs from the known members of
Pseudodiamesa
by a short massive gonostylus with a large lobe along the outer edge and some other features specified in this redescription.
Distribution.
Known only from
type
locality in Teberda Nature Reserve of the North Caucasus.