Shimamyia, Huang & Tachi, 2024

Huang, Yu-Zen & Tachi, Takuji, 2024, A new genus of the tribe Blondeliini (Diptera: Tachinidae: Exoristinae) from the Oriental Region with morphological and molecular evidence, Zootaxa 5496 (2), pp. 151-171 : 154-155

Shimamyia gen. nov.

Type species: Medinodexia orientalis Shima, 1979 .

Diagnosis. Two to 3 postpronotal setae, arrange in a triangle; 2 presutural and 3 postsutural dorsocentral setae; 2–3 katepisternal setae; fore tibia with 1 posterior setae; mid tibia with 1 ventral setae; abdominal dorsum black in ground color. Male. Hair very dense, recumbent and fine on dorsum of abdominal tergite 5 or 4–5; cerci strongly divergent, nearly V-shaped with some setae along entire length in dorsal view; pregonite and postgonite slender and straight; epiphallus long and slender, not positioned at the anterior end of the phallus. Female. Hind coxa and trochanter without any blunt setae on the ventral part; abdominal tergite 3–5 all with a pair of median discal setae; abdominal tergite 7 and sternite 7 not fuse, sternite 7 produced downward posteroventrally and forming a sharply pointed piercer.

Description. Body length: 4.67–7.48 mm.

Male. Head black in ground color, fronto-orbital plate, parafacial, postorbit, face and gena with grayish white pruinosity; antenna dark brown to black; arista brown; palpus dark brown to black. Vertex 0.19–0.25 of head width; inner vertical seta strong, 0.27–0.70 of eye height; outer vertical seta indistinct or present, if present 0.25–0.58 times as long as inner vertical seta; ocellar setae strong, proclinate, about as long as anterior reclinate orbital seta; frontal vitta 1.1–3.2 times as wide as fronto-orbital plate at middle; 6–9 frontal setae, lowest seta at level of middle of pedicel; 2 reclinate orbital setae, anterior seta stronger than posterior one; parafacial bare, slightly narrowed in lower part, 0.5–1.2 times as wide as postpedicel at mid-height; face concave; facial ridge with several setae on lower 0.14– 0.47; lower facial margin not protruded in lateral view; vibrissa arising at level of lower margin of face; compound eye bare; gena 0.15–0.25 of eye height; occiput flattened; upper occiput with 1–2 rows of black setae; antenna not reaching level of lower facial margin. Antenna with postpedicel 2.0–3.7 times as long as pedicel, 2.8–4.3 times as long as wide; arista thickened on basal 0.15–0.25, 2nd aristomere about as long as wide; palpus very weakly clavate, 0.76–1.17 times as long as postpedicel; prementum 1.56–3.00 times as long as wide.

Thorax black in ground color; postpronotal lobe, notopleuron, anepisternum and katepisternum with dense grayish white pruinosity; presutural area with 1 longitudinal gray vittae. Two to 3 postpronotal setae, arrange in a triangle; 2–3 presutural and 3 postsutural acrostichal setae; 2 presutural and 3 postsutural dorsocentral setae; 1 presutural and 3–4 postsutural intra-alar setae; 3 postsutural supra-alar setae, first postsutural seta fine; proepisternum bare; 2–3 katepisternal setae; anatergite bare; scutellum with 3–4 pairs of marginal setae, basal seta strong, subapical setae strong and divergent, about as long as lateral seta, apical seta sometimes present; a pair of discal setae usually present. Wing hyaline or tinged with yellow to brown anteriorly; tegula black, basicosta dark brown to black; lower calypter yellow to brown. Second costal sector setose ventrally; relative lengths of 2nd, 3rd and 4th costal sectors 1.0:2.2–3.3:1.0–1.7; distance of vein M from crossvein dm-cu to bend about 0.72–1.05 times distance between bend and wing margin. Legs brown to black, pulvilli pale yellow. Fore tibia with 1 posterior seta; mid tibia with 1 anterodorsal, 1–3 posterodorsal, 1 ventral setae; hind tibia with 1–4 anterodorsal, 2–5 posterodorsal, 1–3 ventral setae.

Abdominal dorsum black in ground color with thin whitish pruinosity on anterior 0.18–0.47 of tergite 3, 0.24– 0.33 of tergite 4, and none to half of tergite 5; mid-dorsal longitudinal vitta distinct on tergites 3–5. Hair very dense, recumbent and fine on dorsum of tergite 5 or 4–5. Syntergite 1+2 with 0–1 pair of lateral discal, a pair of median marginal and 1–2 pairs of lateral marginal setae; tergite 3 with a pair of median discal setae, 0–1 pair of lateral discal, a pair of median marginal and 1–2 pairs of lateral marginal setae; tergite 4 with a pair of median discal setae, 0–1 pair of lateral discal and 4–10 marginal setae; tergite 5 with 2–8 discal and 4–12 marginal setae; sternite 5 rounded anteriorly, with some setae on posterior half. Postabdomen. Epandrium nearly trapezoidal and rounded dorsally in lateral view, with some setae; surstylus cylindrical and rounded apically with some setae on apical 1/3– 2/3, sometimes swollen at middle in lateral view, tapering and curved inward, sometimes with some setae on apical 1/3–1/ 2 in dorsal view; cerci rounded apically in lateral view, nearly V-shaped with some setae along entire length in dorsal view; hypandrial arms not fused; pregonite fused with epandrium ventrally at base, pointed or rounded apically, sometimes with a seta apically; postgonite longer than epiphallus and rounded apically; epiphallus long, slender and rounded apically, sometimes swollen apically; distiphallus membranous medially with many spinules ventrally in lateral view.

Female. Differs from male as follows: vertex about 0.26–0.31 of head width; outer vertical seta present, 0.33– 0.50 times as long as inner vertical seta; 3–7 frontal setae; 2 proclinate orbital setae; gena 0.20–0.35 of eye height; abdomen without dense, recumbent and fine hair on dorsum of abdominal tergite 4 or 5; postabdomen with sternite 7 produced downwardly at posteroventral porting and forming a sharply pointed piercer.

Etymology. The new genus is named after Dr. Hiroshi Shima, the esteemed researcher who dedicated his career to Tachinidae taxonomy, providing descriptions of the previous Medinodexia species, M. orientalis and M. exigua .

Remarks. In Shimamyia males, the cerci exhibit a pronounced divergence from the anterior side, forming an almost V-shaped configuration. Females exhibit a piercing ovipositor with abdominal tergite 7 and sternite 7 remaining unfused, and only sternite 7 forming a sharply pointed piercer. These distinct postabdomen characteristics may be unique to the genus, potentially serving as autapomorphies within the Blondeliini tribe. According to the phylogenetic analysis of this study, Shimamyia forms a strongly supported monophyletic clade within one of the clades of Blondeliini .