Parachironomus salsus, Mukherjee & Hazra, 2023

Mukherjee, Bindarika & Hazra, Niladri, 2023, Taxonomic studies on Harnischia complex from India (Diptera: Chironomidae), Zootaxa 5278 (2), pp. 239-263 : 246-248

Parachironomus salsus sp. n.

GenBank Accession No. OP683427

urn:lsid:zoobank.org:act:5C145280-F27F-4916-8678-C55A2A150EC9

Material examined. Holotype male, labelled ‘ Holotype Parachironomus salsus sp. n., India, West Bengal, Purba Barddhaman [23.2393° N, 87.8512° E], 16.viii.2021, Coll. N. Hazra’ . Paratype 1 male, same data as holotype, 07.iii.2022, Coll. N. Hazra. Paratype 1 male, labelled ‘ Paratype Parachironomus salsus sp. n., India, West Bengal, Purba Barddhaman [23.2441° N, 87.8368° E], 30.iv.2022, Coll. B. Mukherjee’ .

Diagnostic characters. The adult male can be differentiated by the presence of nearly vase shaped anal point, sharply pointed beak like superior volsella and medially swollen gonostylus.

Etymology. The name ‘ salsus ’, a Latin word, refers to the sharp superior volsella.

Male (n=3). Total length 2.9–3.1, 3 mm. Wing length 1.52–1.55, 1.535 mm. Costal length 1.48–1.50, 1.49 mm. Antennal length 0.93–0.96, 0.945 mm.

Colouration. Yellowish thorax with dark brown marking; leg and abdomen yellowish brown. Head. Head width 520–530, 525. Temporal setae 8 (IV 2, OV 4, Po 2). Clypeal setae 15–16. Frontal tubercles absent. Eyes bare with dorsomedial extension of 108–112, 110 µm. AR 1.82–1.90, 1.86; ultimate flagellomere 610–620, 615 µm long. Palpomere lengths (I–V) (µm): 34.5: 27.5–30, 28.75: 85–86.5, 85.75: 120–124, 122: 177. CA 0.55–0.56, 0.555.

Thorax. Scutal tubercle absent. Ac 11, Dc 7, Pa 3, Scts 10, Su 1.

Wing ( Fig. 3A ). VR 1.12–1.14, 1.13. R 1 with 32–34 setae, R 4+5 with 15–18 setae. Brachiolum with 2 setae. Squama with 2 setae. FCu distinctly distal to RM. Anal lobe moderately developed.

Legs. Fore tibia with 2 setae. Mid legs with 2 tibial spurs; each 18.4 µm long with 21 lateral teeth. Hind leg with 2 tibial spurs; 16 µm and 11.5 µm long with 31 teeth. Lengths and proportions of leg segments shown in table III.

Hypopygium ( Figs. 3B–D ).Anal tergite band Y shaped.Anal point basally and apically constricted while slightly expanded medially, 65–69, 67 µm long and 16–20, 18 µm wide, with a median ridge like structure. Laterosternite IX with 3 setae on each side of anal point. Longitudinal and transverse sternapodeme 87.5–90, 88.75 µm and 40 µm long respectively. Superior volsella 53–57.5, 55.25 µm long and 28 µm wide, roughly straight with pointed beak like structure at apical end bearing 2 setae subapically, 1 of the setae (34.5 µm long) placed on a deep and wide pit and other one 16 µm long located on distinct shallow pit. Inferior volsella with a blunt projection covered with microtrichia. Gonocoxite 126.5–130, 128.25 µm long. Gonostylus 165.5 –170, 167.75 µm long, bluntly rounded at apex. HR 0.76–0.77, 0.765. HV 2.29– 2.38, 2.335.

Distribution. India, West Bengal.

Remarks. Presence of distolateral beak on superior volsella with 2 setae arise from distinct pits, long anal point and variable gonostylus assert the placement of the species in the genus Parachironomus Lenz. P. vitiosus Goetghebuer, 1921 is similar with the new species in having somewhat similar shaped superior volsella but differs in the shape of gonostylus and anal point. The new species and P. matapi Spies, Fittkau & Reiss, 1994 have nearly similar shaped gonostylus but differs in the shape of superior volsella and anal point. The new species and P. elodeae ( Townes, 1945) have similar type of superior volsella but they differ in the shape of gonostylus and anal point.

Figures

FIGURE 3. Adult male Parachironomus salsus sp. n. A. Wing, B. Hypopygium (dorsal), C. Hypopygium, scale 0.01 mm, D. Superior volsella, scale 0.01 mm.