Corynoneura palus, Namayandeh & Hudson & Bogan & Hudson, 2024

Namayandeh, Armin, Hudson, Patrick L., Bogan, Daniel L. & Hudson, John P., 2024, Chironomidae (Diptera: Insecta) of Alaska, USA, with descriptions of new species and a checklist, Zootaxa 5511 (1), pp. 1-95 : 29-30

Corynoneura palus sp. nov.

urn:lsid:zoobank.org:act:92559208-840E-4410-BA39-1E8A40CBCEC8

Fig. 4A–F

Type materials. Holotype male; USA, Alaska, Douglas Island, Eagle crest Ski Area , forested bog; 13.vii.2009; leg. P.L. Hudson; dep. UAM.

Etymology. The new species is named after the habitat it was collected from, a forested bog. The word “ palus ” is Latin meaning bog.

Diagnosis. The adult male of C. palus can be distinguished from other species of Corynoneura by the combination of the following characteristics: Antenna with 12 flagellomeres; AR 0.3; VR 2; no S-shaped setae near spur of hind tibia; margin of tergite IX apex bilobed (Type 2), with 2 setae; transverse sternapodome very broad and thick longitudinally; phallapodeme scalpel-shaped, in caudal position of sternapodeme; superior volsella developed, short and crescent-shaped; inferior volsella prominent, long and digitiform; gonostylus evenly curved; megaseta short.

Male (n = 1)

Total length 2.4 mm; wing 0.9 mm long and 0.3 mm wide.

Coloration. Head, thorax brown. Abdominal tergites and hypopygium brown. Sternites, halteres and legs light brown. Wings greyish.

Head. Eyes small and bare. Tentorium long and narrow, 129 μm long ( Fig. 4A ). Temporal setae absent.Antenna with 12 flagellomeres, plume moderate, last segment with around 8 sensilla chaetica ( Fig. 4B ), antennal apex type 2, each of segments 2 and 3 with 2 sensilla chaetica, AR 0.3. Clypeus rectangular, bearing 6 setae, clypeus 38 μm long and 78 μm wide (maximum), cibarial pump type 2. Palpal segments lengths (in μm): 37, 21, 22, 34, 51; third palpal segment with 1 sensilla clavata.

Thorax. Dorsocentrals 5, prealars 2, scutellars 2.

Wing ( Fig. 4C ). VR 2; C 194 μm long; C/Wing length 0.21; Cu 443 μm long; Cu/Wing length 0.48. Wing width/ length 0.3. Brachiolum with 1 seta, C with 5 setae.

Legs. Fore tibial spurs 24 and 11 μm long, mid tibial spurs 8 and 7 μm long, hind tibial spurs 35 and 14 μm long. Hind leg comb with around 15 spines ( Fig. 4D ). Width of the hind tibia (a) 35 μm, length of ventral elongation (b) 21 μm, length of strong broadened part (c 1) 35 μm, total length of broadening (c 2) 62 μm, width of the hind tibia (d) 19 μm. No S-shaped setae near spur. Lengths and proportions of legs as in Table 5.

Hypopygium ( Fig. 4E–F ). Margin of tergite IX apex bilobed (Type 2), with 2 setae 9 μm long ( Fig. 4E ). Transverse sternapodome very broad and thick longitudinally, 37 μm wide; phallapodeme scalpel-shaped, 67 μm long, in caudal position of sternapodeme. Superior volsella developed, short and crescent-shaped, well separated from inferior volsella. Inferior volsella prominent, long and digitiform, almost 2/3 rd the length of gonostylus, located at the midsection of gonocoxite, covered in simple setae. Gonostylus evenly curved, 26 μm long; megaseta 7 μm long. HR 2.4, HV 9.1.

Remarks

Adult male of this species keys out to Corynoneura capitanea Fu and Saether, 2012 based on Fu et al. (2019). A combination of AR 0.3; medially located large, long, and digitiform inferior volsella; wider sternapodeme; a uniformly curved gonostylus with short megaseta separates this species from C. capitanea . C. palus sp. nov. is also similar to Corynoneura sp. near lacustris Edwards 1924 (= Corynoneura n. sp. 11 Bolton, 2007). A combination of brown color; AR 0.3; lack of S-shaped seta; bilobed posterior margin of tergite IX with 2 setae; prominent and long inferior volsella; wider sternapodeme; shorter phallapodeme; and shape of gonostylus separates the two species.

Figures

FIGURE 4. Corynoneura palus sp. nov. adult male (A–F).A. tentorium, B. last flagellomeres of antenna, C. wing, D. hind tibia, E. margin of tergite IX apex, F. hypopygium. Scale bars are 20 µm.