The chironomids (Diptera, Chironomidae) described by Lundström (1915) from arctic Siberia, with a redescription of Derotanypus sibiricus (Kruglova & Chernovskii)
Author
Saether, Ole A.
text
Zootaxa
2004
595
1
35
journal article
10.5281/zenodo.157906
1747e372-76a3-4a7d-b64c-fbbfa0b7e9c8
11755326
157906
4CE6F8B3-1872-4C00-886A-8FF1DCF1390C
Orthocladius (Orthocladius) pallidicornis
Lundström, 1915
: 13
(
Figs. 14–18
)
Type
material
.
Lectotype
ɗ, here designated:
RUSSIA
: CharaUllach Mts.,
12 vii 1902
, M. I. Brussnew.
Paralectotypes
: 3 Ψ (including 1 misidentified
Tokunagaia
sp., and 1 misidentified
Tanytarsini
lacking the abdomen), as
lectotype
except
12 vii and 16–17 vii 1902
.
MALE IMAGO (n = 1)
Total length
3.63 mm
. Wing length
2.11 mm
. Total length/wing length 1.72. Wing length/length of profemur 2.86. Coloration pale brown with dark brown vittae, postnotum and preepisternum.
Head. AR 0.95. Ultimate flagellomere
420 m
long. Temporal setae 15, including 7 inner verticals, 4 outer verticals, and 4 postorbitals. Clypeus with 7 setae. Tentorium
173 m
long,
26 m
wide. Stipes
150 m
long,
41 m
wide. Palpomere lengths (in m): 38, 45, 101, 94, 173. Third palpomere with 2 lanceolate sensilla clavata
15 m
long.
Thorax. Antepronotum robust, projecting, with 2 setae. Acrostichals apparently 11, dorsocentrals 7, prealars 3. Scutellum with 4 setae.
Wing. VR 1.10. Anal lobe conspicuous, projecting [, as in
O. (O.) decoratus
(Holmgren)
, see
Soponis (1977: fig.14 f)
]. Costal extension
8 m
long. Brachiolum with 1 seta, other veins bare. Squama with 15 setae.
Legs. Spur of front tibia
41 m
long, spurs of middle tibia 26 and
23 m
long, of hind tibia 60 and
23 m
long. Width at apex of front tibia
41 m
, of middle tibia
39 m
, of hind tibia
45 m
.
Sensilla chaetica (possibly only curved setae?): 6 spaced along full length of ta1 of mid leg, and 2 apically on hind leg. Lengths (in m) and proportions of legs: Hypopygium (
Fig. 14
). Tergite IX with 17 setae, including 9 on anal point; laterosternite IX with 5 setae. Anal point sharply pointed,
38 m
long. Phallapodeme
60 m
long; transverse sternapodeme
68 m
long, oral projections indicated. Virga
19 m
long, apparently consisting of several longitudinally arranged, shorter spines. Gonocoxite
233 m
long, superior volsella prominent, hookshaped, with conspicuously broad microtrichia; inferior volsella weak. Gonostylus
109 m
long, nearly semicircular, megaseta
11 m
long. HR 2.14, HV 3.33.
| fe |
ti |
ta1 |
ta2 |
ta3 |
ta4 |
ta5 |
LR |
BV |
SV |
BR |
| p1 |
737 |
917 |
529 |
|
|
|
|
0.58 |
|
3.13 |
|
| p2 |
794 |
784 |
359 |
217 |
170 |
113 |
99 |
0.46 |
3.23 |
4.39 |
2.9 |
| p3 |
775 |
917 |
482 |
265 |
213 |
123 |
|
0.53 |
|
3.51 |
3.7 |
FEMALE IMAGO (n = 1)
Total length
2.93 mm
. Wing length
2.49 mm
. Total length/wing length1.24. Wing length/length of profemur 3.32. Coloration as in male.
Head. AR 0.58. Lengths of flagellomeres (in m): 98, 45, 45, 45, 139. Temporal setae 12, consisting of 4 outer verticals; 4 inner verticals, and 4 postorbitals. Clypeus with 13 setae. Tentorium
169 m
long,
30 m
wide; stipes
184 m
long,
41 m
wide. Palpomere lengths (in m): 38, 53, 124, 94, 180. Coronal suture nearly complete,
158 m
long.
FIGURES 15–21.
Orthocladius
,
Paralimnophyes
and
Chaetocladius
, 15–18: female genitalia,
Orthocladius (Orthocladius) pallidicornis
Lundström
, 15: ventral view, 16: apodeme lobe, 17: dorsomesal lobe, 18: ventrolateral lobe, 19–20:
Paralimnophyes trilineatus
(Lundström)
comb. n.
, 19: male hypopygium, 20: female genitalia, lateral view, 21:
Chaetocladius perennis
(Meigen)
, male hypopygium from lectotype of
Camptocladius incertus
Lundström.
Thorax. Antepronotum with 6 lateral setae. Acrostichals 10, dorsocentrals 7, prealars 3. Scutellum with 4 setae.
Wing. VR not measurable. Costal extension
38 m
long. Brachiolum with 1 seta, R4+5 with 6 setae, costal extension with 2 nonmarginal setae. Squama with 14 setae.
Legs. Spur of front tibia
41 m
long, spurs of mid tibia
30 m
and
26 m
long, spurs of hind tibia
64 m
and
23 m
long. Width at apex of front to hind tibiae (in m) as: 53, 45, 53. Comb of 9 setae; shortest seta
26 m
long. longest seta
45 m
long. Pseudospurs present on ta1 of mid and hind legs,
28 m
long. Sensilla chaetica not observed. Lengths (in m) and proportions of legs:
| fe |
ti |
ta1 |
ta2 |
ta3 |
ta4 |
ta5 |
LR |
BV |
SV |
BR |
| p1 |
709 |
860 |
520 |
321 |
203 |
132 |
104 |
0.60 |
2.75 |
3.02 |
2.7 |
| p2 |
756 |
756 |
321 |
198 |
142 |
76 |
95 |
0.43 |
|
4.70 |
2.1 |
| p3 |
841 |
964 |
463 |
274 |
213 |
128 |
113 |
0.48 |
3.12 |
3.90 |
2.6 |
Abdomen. Setae on sternites I–VIII as: 0, 2, 8, 9, 7, 15, 14, 18.
Genitalia (
Figs. 15–18
). Half of tergite IX missing, other half with about 7 setae. Gonocoxite with 10 setae. Cercus
105 m
long. Seminal capsule
71 m
long,
53 m
wide. Spermathecal ducts nearly straight. Gonapophysis VIII divided, with large ventrolateral (
Fig. 18
) and dorsomesal (
Fig. 17
) lobes. Apodeme lobe (
Fig. 16
) strongly sclerotised, conspicuous. Notum
128 m
long.
Remarks
The species keys to
O. (O.) decoratus
(Holmgren)
in
Soponis (1977)
whose redescription included the
type
material.
Rossaro et al. (2003)
also redescribed the species including the
lectotype
. They report their specimens as having a not produced anal lobe of the wing, and 10 scutellars in a single row. Both the
lectotype
of
O. (O.) decoratus
,
other specimens of
O. (O.) decoratus
including some at the Museum of Zoology, Bergen examined by Soponis and the present species are characterised by the strongly developed anal lobe.
O. (O.) decoratus
has 8–15 unibiserial scutellars, while the present species has 4 uniserial scutellars.
O. (O.) decoratus
has 5–11 setae on vein R,
O. (O.) pallidicornis
none.
O. (O.) pallidicornis
also differs from
O. (O)
decoratus
in a number of other features such as a lower antennal ratio (0.95 compared to 1.4–2.0), the lower front leg ratio (0.58 with a wing length of
2.11 mm
compared to 0.69–0.77 with wing lengths of
2.20–2.85 mm
), the conspicuous and unique microtrichia on the superior volsella, the even more reduced inferior volsella, and the nearly semicircular gonostylus.