Linevitshia yezoensis Endo, 2007

Makarchenko, Eugenyi A. & Semenchenko, Alexander A., 2025, Confirmation of a species status and redescription of Linevitshia yezoensis Endo, 2007, stat. resurr. (Diptera: Chironomidae: Protanypodinae) from Hokkaido (Japan), Zootaxa 5609 (1), pp. 145-150 : 146-147

Linevitshia yezoensis Endo, 2007 , stat. resurr.

( Figs. 1–4 , 7–8 )

Linevitshia yezoensis Endo in Endo, Makarchenko & Willassen, 2007: 93, Figs 1–4 , 7 –13; Ashe & Connor 2009: 292; Makarchenko & Endo 2009: 65.

New material examined. Japan: 5 adult males, 2 adult females, Hokkaido, Obihiro City, Taisho, Nuppuku River , N 42.819383, E 143.187231, altitude 102 m a.s.l., 06.X. 2024, leg. K. Endo.

Adult male (n = 14, except when otherwise stated) Total length 3.0– 4.14 mm. Total length/wing length 1.30–1.52. Coloration. Body largely brown to dark brown; head and thorax more or less grayish.

Head. Eyes reniform with weak microtrichia between ommatidia. Frons with weak protrusions near dorsomesal corner of the eye. Temporal setae including 0–1 weak and short inner verticals and 3–5 stronger postorbitals. Clypeus without setae. Antenna with 13 flagellomeres and well-developed plume; ultimate flagellomere with 2 subapical setae 38–40 μm long, pedicel with 2–3 setae, scape without setae. AR 1.00–1.11. Palpomere length (μm): 40–48, 61–79, 112–141, 127–146, 192–225.

Thorax. Antepronotum with U-shaped notch in frontal view, with 4–9 dorsal and 14–21 lateral setae. Acrostichals 17–33, dorsocentrals 11–16, prealars 6–9, supralars 1–3. Scutellum with 10–16 setae. Posterior anepisternum II with 3–5 setae, epimeron II with 3–8 setae, preepisternum without setae.

Wing. Wing length 2.12–2.6 mm, width 0.56–0.68. Costal extension 60–80 μm long; R 2+3 weak, but distinct. Anal lobe weakly developed. Membrane without macrotrichia. Brachiolum with 3–5 setae. R with 22–28 setae, R 1 with 5–11 setae, R 4+5 with 6–11 setae. RM/Mcu 3.2–3.5. Alula with 4–9 setae. Squama with 18–25 setae.

Legs. Spur of front tibia 70–79 μm. Spurs of mid tibia 56–78 and 60–75 μm. Spurs of hind tibia 81–90 and 65–73 μm long. Hind tibial comb with 9–11 setae. Tarsal sensilla chaetica absent. Ta 4 cylindrical; ta 5 slightly curved; pulvilli small; tip of claws serrate, with approximately 5 teeth. Lengths and proportions of leg segments are as in Table 1 .

Hypopygium ( Figs. 1–4 , 7–8 ). Tergite IX with 9–14 setae. Anal point absent. Laterosternite IX with 8–11 setae. Gonocoxite simple, 160–180 μm long. Transverse sternapodeme broadly arched ( Figs. 1 , 7 ), 128–164 μm long and 40–56 μm width; TSA length/TSA width 3.7–4.5. Phallapodeme 96–120 μm long; aedeagal lobe distally with yellowish, weakly chitinized, finger-like inner part, which with large, noticeably protruding “heel” basally ( Fig. 8 ). Gonostylus 88–96 μm long; in distal part with strong setae 12–22 μm long and 1–2 apical megaseta 12–14 μm long ( Fig. 1 ). HR 1.7–2.4.

Pupa of L. yezoensis is no different from that of L. prima ( Endo et al. 2007) .

Larva unknown.

Remarks. Comparison of adult males of L. prima and L. yezoensis showed that the values of most morphological characters of these species overlap and do not provide clear differences, although males of the first species are larger, have longer wings and a greater number of acrostichal and dorsocentral setae of the mesonotum, as well as setae of the wing squama ( Table 2 ). The main difference between these species lies in the structure of the hypopygium. Thus, the length of the gonostylus of L. prima 112–124 μm, gonocoxite—200–288 μm, length of TSA 180–228 μm, width of TSA 24–46 μm, ratio of TSA length to its width 5.0–5.9, gonostylus with 1–4 megasetae. In L. yezoensis , length of gonostylus 88–96 μm, gonocoxite—160–180 μm, length of TSA 128–164 μm, width of TSA 32–56 μm, the ratio of the TSA length to its width 3.0–4.5, gonostylus with 1–2 megasetae ( Table 2 ). However, the more important difference between these two species is in the complex structure of the aedeagal lobe, which is difficult to describe, but nevertheless the internal part of aedeagal lobe in L. prima is finger-like, without a “heel” basally ( Figs. 4–6 ), and in L. yezoensis it is also finger-like but with a large, noticeably protruding “heel” basally ( Figs. 3 , 7–8 ). It should be noted that the inner part of the aedeagal lobe of L. yezoensis may sometimes be invisible ( Fig. 3 ) or difficult to distinguish ( Fig. 4 ).

Distribution. Known from type locality in Hokkaido ( Japan) and it is possible that this species lives on Kunashir Island (Kurile Islands) and in Oriental China ( Sun et al. 2019), but this can only be confirmed after DNA barcoding of specimens from these places.

Figures

FIGURES 1–4. Males of Linevitshia yezoensis Endo (1, 3–4) and L. prima Makarchenko (2). 1–2, hypopygium in dorsal view; 3–4, endoskeleton. IEL—inner part of aedeagal lobe.

FIGURES 5–8. Malesof LinevitshiaprimaMakarchenko (5–6) andL.yezoensisEndo (7–8). 5–7, endoskeleton;8,phallapodeme and aedeagal lobe. IEL—inner part of aedeagal lobe; TSa—transverse sternapodeme; Pha—phallapodeme. Scale bars are 50 µm.