Tachinus (Tachinus) dujieae, Hashizume & Schülke & Maruyama, 2024

Tachinus (Tachinus) dujieae

Hashizume, Schülke & Maruyama, sp. nov. [Japanese name: Takane-marukubi-hanekakushi]

( Figs 3A–C, 3E–L View Fig )

Type material. HOLOTYPE: ♁, JAPAN: HONSHU: alt. 2530 m, Utsugidaira, Utsugi-dake, Komagane-shi, Nagano-ken, 22.vii.2001, K. Haga leg. ( KUM) . PARATYPES: 2 ♀♀, same data as holotype ( KUM).

Diagnosis. This species can be distinguished from other Tachinus species by the combination of the shape of aedeagus, tergites, and sternites. The new species belongs to the T. rufipes group and is similar to T. rishirianus Watanabe & Shibata, 1965 in appearance. Tachinus dujieae sp. nov. can be distinguished from the latter by the following characteristics: 1) microsculpture of dorsal side of pronotum and elytra composed of finer isodiametric meshes (in T. rishirianus , microsculpture composed of wider, more broken meshes); 2) incisions between inner lobes of male sternite VIII deep; 3) inner lobes of female tergite VIII not exceeding apices of outer ones; 4) without triangular process between inner lobes of female sternite VIII; 5) apex of parameres bi-curved (in T. rishirianus , parameres abruptly thinned apically). In Japan, there are four species in the T.rufipes group ( T. bipustulatus (Fabricius, 1775) , T. rishirianus , T. trifidus Sharp, 1888 and T. dujieae sp. nov.). Tachinus chinensis Bernhauer, 1933 , described from western Sichuan, is similar to T. dujieae sp. nov. in the appearance of aedeagus but differs in pointed center of male sternite VII.

Description. Measurements (holotype (male)/ paratype (female) in mm). LE: 0.28/0.28; TL: 0.42/0.47; HW: 1.07/1.13; HL: 0.92/0.93; PW: 1.97/2.04; PL: 1.27/1.29; EL: 1.62/1.68; ELL: 1.78/1.86; EW: 1.96/2.11; FBL: 3.75/4.00; BL: 5.75/6.50; LMtTi: 1.49/1.51; LMtTr: 0.97/0.89. Indices (holotype / paratype). LE/TL: 0.67/0.60; LE/HW: 0.26/0.25; HL/HW: 0.86/0.83; HW/PW: 0.54/0.55; HW/PL: 0.84/0.87; PL/PW: 0.65/0.63; PL/EL: 0.79/0.77; PW/EW: 1.01/0.97; ELL/EW: 0.91/0.88. Length ratio of antennomeres I–XI (holotype). 35: 22: 26: 18: 27: 27: 27: 26: 27: 24: 32. Ratio length/width of antennomeres I–XI (holotype). 1.3, 1.1, 1.1, 1.1, 1.3, 1.4, 1.5, 1.6, 1.7, 1.9, 2.0.

Male ( Fig. 3A View Fig ). Body brown, head darker, antennomeres I–IV yellowish brown, antennomeres V–XI dark brown.

Head slightly transverse, without punctures, with microsculpture composed of isodiametric meshes. Eyes protruding from outline of head. Supraorbital puncture on each side small with very short seta. Antennomeres I–IV glossy, with a few longer setae, antennomeres V–XI dull.

Pronotum transverse, moderately convex in cross-section, without punctures, with microsculpture as on head.Anterior and posterior angles broadly rounded. Median smooth area from basal half to basal 1/4 of pronotum vertically long.

Scutellum triangular. Elytra slightly transverse, with indistinct fine punctation, with microsculpture as on head ( Fig. 3C View Fig ). Posterior margins rounded, forming clear sutural angle. Hind wings developed.

Abdomen narrowed obliquely posteriad, with fine punctation more distinct than that of elytra, with microsculpture as on head. Tergites III–IV with pruinose spots. Pruinose spots of tergite IV more elongate than those of tergite III. Tergite VIII ( Fig. 3F View Fig ) with four lobes, inner lobes longer than outer ones. Sternite VII ( Fig. 3E View Fig ) shallowly and broadly emarginate; field of modified setae narrow, arranged along emargination. Sternite VIII ( Fig. 3G View Fig ) deeply incised between inner lobes, midlength 0.53 times as long as depth of incision, inner lobes slightly curved inward towards apices. Aedeagus ( Figs 3H–I View Fig ) with parameres long, apices of parameres twice curved in lateral view.

Legs moderately long. Protarsal segments I–IV dilated.

Female ( Fig. 3B View Fig ). Most characteristics similar to male. Protarsi slender. Meso- and metatarsi shorter than those of male. Tergite VIII ( Fig. 3J View Fig ) with four lobes, inner lobes deeply separated from each other and as long as outer ones, outer incisions deeper than median one. Sternite VIII ( Fig. 3K View Fig ) with short setae at central region, and with six lobes, inner lobes broader than outer lobes and apically each with several short light-colored setae.Abdominal segments IX, X and spermatheca as in Fig. 3L View Fig . Spermatheca with intricately coiled spermathecal duct.

Etymology. The new species is dedicated to Mrs. Du Jie, the wife of the collector of the type series, Mr. Kaoru Haga, as a reward for her support of his entomological studies.

Biology. All individuals were collected from human feces in a grassland at an altitude of 2530 m.

Distribution. Japan (central Honshu). Tachinus dujieae sp. nov. was found only at one site in the alpine zone of central Honshu. However, since many species of the subgenus Tachinus with developed hind wings are widely distributed in mainland Japan, it is possible that T. dujieae sp. nov. may be found elsewhere in the future.

Remarks. The tergite VIII and sternite VIII of all specimens have lost some of the setae that were originally thought to be present.