Three new species of Orthocladius subgenus Eudactylocladius (Diptera: Chironomidae) from Norway
Author
Ole
Author
Saether, A.
text
Zootaxa
2004
508
1
12
journal article
10.5281/zenodo.157963
ae45553a-04a2-42a5-9ab3-b39e06280102
11755326
157963
Orthocladius
(
Eudactylocladius
)
schnelli
sp. n.
(
Figs 2
,
9, 14
)
Type
material
Holotype
ɗ,
NORWAY
:
Svalbard
, Spitzbergen, Vasa Peninsula, Lake Birgervatnet,
79º 48'N
,
11º 37'E
,
15 viii 1983
, Ø. A. Schnell (
ZMBN
Type
No. 395).
Diagnostic characters
The male imago is separable from the other species of the subgenus by having dense microtrichiae on both dorsal and ventral sides of gonostylus, strongly sclerotized anal point with nearly parallelsided apex, wings greyish clouded with dark squama, ultimate flagellomere more than
650 m
long, gonocoxite with both volsellae weakly developed and no sensilla chaetica on tarsi.
Etymology
Named after the collector of the species.
Male imago
(n =1)
Total length
4.50 mm
. Wing length
3.17 mm
. Total length/wing length 1.42. Wing length/length of profemur 3.13. Coloration dark brown with thoracic markings barely separable from ground colour. Wing pale greyish clouded with squama nearly black.
Head. AR 1.25. Ultimate flagellomere
676 m
long. Temporal setae 17, including 6 inner verticals, 6 outer verticals, and 5 postorbitals. Clypeus with 11 setae. Cibarial pump, tentorium and stipes as in
Fig. 9
. Tentorium
199 m
long,
49 m
wide. Stipes
184 m
long,
75 m
wide. Palpomere lengths (in m): 45, 71, 158, 135, 214.
Thorax. Antepronotum with 5 setae. Dorsocentrals 13, acrostichals 14, prealars 5. Scutellum with 14 setae.
Wing. VR 1.07. Costal extension
53 m
long. R with 18 setae, R1 with 5 setae. Squama with 15 setae.
Legs. Spur of front tibia
79 m
long, spurs of middle tibia 45 and
41 m
long, of hind tibia 86 and
39 m
long. Width at apex of front and middle tibia each
53 m
, of hind tibia
58 m
.
Pseudospurs present on ta1 and ta2 of mid and hind leg,
34–38 m
long. Sensilla chaeticae absent. Lengths (in m) and proportions of legs:
| fe |
ti |
ta1 |
ta2 |
ta3 |
ta4 |
ta5 |
LR |
BV |
SV |
BR |
| p1 |
1011 |
1257 |
879 |
529 |
340 |
222 |
132 |
0.70 |
2.57 |
2.58 |
2.5 |
| p2 |
1115 |
1162 |
543 |
321 |
236 |
142 |
123 |
0.47 |
3.43 |
4.19 |
2.6 |
| p3 |
1210 |
1418 |
813 |
425 |
302 |
170 |
142 |
0.57 |
3.31 |
3.23 |
4.5 |
Hypopygium (
Fig. 2
). Tergite IX with 18 setae including 2 on anal point, laterosternite IX with 8 setae. Anal point
47 m
long. Phallapodeme (
Fig. 14
)
94 m
long, transverse sternapodeme (
Fig. 14
)
143 m
long, oral projections well developed, median portion of transverse sternapodeme very weak. Gonocoxite
326 m
long, with two weak but distinct volsellae, strong microtrichiae starting close to base and reaching to apex of apical lobe. Gonostylus
113 m
long, densely covered with microtrichiae, widest near apex; crista dorsalis apical, truncate; megaseta
19 m
long. HR 2.90, HV 3.98.
Comments
A slightly cloudy wing with squama nearly as dark, is also found in at least some specimens of
O
. (
E
.)
fuscimanus
(Kieffer)
. The wing of the present species, however, is longer than in any other species examined, and the ultimate antennal segment longer than in other species except
O
. (
E
.)
gelidus
. The strongly sclerotised anal point appear to be unique among the members of the subgenus.
Distribution and ecology
The species is known only from the
type
locality on Spitzbergen, which is among the northernmost lakes on the archipelago. The only chironomid collected in the profundal zone was
Oliveridia tricornis
(Oliver)
. Kick samples along the shore yielded larvae of
Diamesa bohemani
Goetghebuer
,
Diamesa arctica
(Boheman)
, undetermined
Diamesa
,
Metriocnemus obscurip
es (Holmgren) and
Oliveridia tricornis
. Adults of
Diamesa hyperborea
Holmgren
were collected together with the present species.