Zavrelimyia (Paramerina) falcata, Mondal & Mukherjee & Hazra, 2022

Mondal, Debarshi, Mukherjee, Tuhar & Hazra, Niladri, 2022, On a new species of the genus Zavrelimyia Fittkau, 1962 (Diptera: Chironomidae) from India with cladistic relationship and a world key to the known males, Zootaxa 5154 (3), pp. 365-379 : 367-369

Zavrelimyia (Paramerina) falcata sp. n.

GenBank accession number: MT106670

Figures 1A–E urn:lsid:zoobank.org:act:B45C85B5-71B7-40E4-9192-EFC9B62284A3

Type Material. Holotype male, INDIA: West Bengal, Kalimpong (27°3’N, 88°28’E), 07.VIII.2019, light trap, Coll. D. Mondal. Paratypes 4 males, data as holotype ; 2 males, as holotype except 10.VIII.2019, Coll. T. Mukherjee’ .

Etymology. From Latin ‘ falcata ’, referring to the sickle-shaped megaseta on the gonostylus.

Diagnosis. The male adult of the new species is distinguished from the species of the subgenus Paramerina by the following combination of characters: T II–VIII banded, foretibial spur elongate, posterior margin of T IX with transverse row of setae, gonocoxite bulbous in shape, gonostylus robust with strongly curved, sickle-shaped megaseta.

Description. Male imago (n= 5). Total length 2.30–2.36 (2.30) mm. Wing length 1.52–1.57 (1.55) mm, width 0.39–0.42 (0.40) mm. L/W 3.76–3.89 (3.87). Total length / wing length 1.46–1.51 (1.48).

Colouration. Head dark brown, with maxillary palp light brown and antenna pale brown. Thorax brown, with scutal vittae dark brown. Wing with cross vein pale. Gonocoxite brown; gonostylus brown, with darkened megaseta.

Head. Antenna ( Figure 1A ) with strong apical seta, AR 1.45–1.47 (1.47). Temporal setae biserial, consisting of 8–10 IV, 3–5 OV, and 2–3 Po. Frontal setae 3–5 in number. Eyes bare, with dorsomedian extension 110–130 (130) µm long. Clypeus with 20–25 (23) setae. Length of palpomeres I–V (µm): 62–65 (65), 69–75 (72), 132–148 (143), 155–174 (156), 212–228 (228). CA 0.46–0.49 (0.49), CP 0.75–0.79 (0.78).

Thorax. Antepronotum with 5–7 (6) lateral setae. Scutal tubercle absent. Acrostichals 28, irregularly biserial; dorsocentrals 24–28 (26), biserial; scutellars 11–12 (12).

Wing ( Figure 1B ). Wing membrane with dense macrotrichia. Squama with 9–12 (9) setae. Brachiolum with 2 setae. Costa not produced. R 2 very short, R 3 short and apically fading out. Anal lobe moderately developed. CR 0.86–0.89 (0.87), VR 0.85–0.87 (0.85).

Legs ( Figure 1C ). Fore-tibial spur 59–62 (62) µm long, bearing 4 lateral teeth; spurs of mid tibia 32–36 (32) µm and 68–72 (69) µm long, bearing 2 and 4 lateral teeth respectively; spur of hind tibia 29–33 (30) µm and 72–76 (74) µm long, with 2 and 3 lateral teeth respectively. Hind tibial comb bearing 4–5 (4) bristles. Lengths (µm) and proportions of leg segments as in Table 1 .

Abdomen ( Figure 1D ). Abdominal segments banded. T IX with 5 posterior setae in irregular row.

Hypopygium ( Figure 1E ). Anal point small, conical. Gonocoxite bulbous, 107–120 (110) µm long, 65–67 (65) µm wide, 1.69 times as long as broad; inner border of basal 1/3 with dense field of short setae. Gonostylus robust, 75–97 (76) µm long, 0.67 times as long as gonocoxite with megaseta sickle-shaped, 9–10 (9) µm long. Phallapodeme 104–107 (106) µm long extending occupying 1.04 of gonocoxite; sternapodeme 51–53 (53) µm long. HR 1.41–1.50 (1.44); HV 2.90–3.10 (3.02).

Remarks. The adult male is similar to that of Indian species Zavrelimyia (Paramerina) clara ( Hazra, Saha, Mazumdar and Chaudhuri, 2011) in having the similar characters of abdominal punctation, LR I and CR. The new species has higher AR, and HV than Z. (P.) clara . The distribution of setae in posterior border of TIX is also different. The new species appears alike to Zavrelimyia (Paramerina) divisa ( Walker, 1856) and Zavrelimyia (Paramerina) dolosa ( Johannsen, 1932) having the similar character of costa, which is not produced but disagrees in abdominal colouration. It is close to another Indian species Zavrelimyia (Paramerina) quininficia ( Chaudhuri and Debnath, 1985) in AR but has higher values of CR and HR. Shape of the gonocoxite and gonostylus also differ between the two species. The robust gonostylus of Z. (P.) falcata sp.n. is unique among the species of the subgenus. The combination of characters stated in the diagnosis justifies it to be a new member of the genus. The submitted sequences have shown 93.16 % similarity with LC 462314 in GenBank of NCBI ( Figure 2 ).

Distribution and bionomics. So far, the species has been found only in the type locality. The imagines were collected from meadow grasslands in Kalimpong, using a light trap. The altitude is 1247 meters above mean sea level. The temperature ranges from 23°C to 28°C at the beginning of August.

Figures

FIGURES 1A–E. Male of Zavrelimyia (Paramerina) falcata sp. n. A, Terminal flagellomere; B, wing; C, foretibia, mid tibia, and hind tibia from left to right; D Abdomen; E, hypopygium, dorsal view. Scale: A, 10 μm; B, 500 μm; C–D, 50 μm.

FIGURE 2. The tree showing genetic relationship following Neighbor-Joining method based on the COX1 gene sequences of Zavrelimyia (Paramerina) falcata sp. n. and reference sequences of tanypod midges from GenBank. Scale: 0.020 substitutions per nucleotide position.