Cyzenis equifacialis, Shima & Abe & Libra, 2021

Shima, Hiroshi, Abe, Tomokazu & Libra, Martin, 2021, Tachinid flies (Diptera: Tachinidae) reared from deciduous plant-feeding lepidopteran larvae at Hokkaido University Tomakomai Forest (Japan), with descriptions of three new species, Zootaxa 5060 (2), pp. 275-295 : 284-287

Cyzenis equifacialis sp. nov.

( Figs 13–17 , 28–29 , 39–40 )

Diagnosis. A small to medium-sized grayish goniine tachinid. Head dichoptic; eye haired; 2 reclinate orbital setae; antenna with postpedicel elongate, about 7 times as long as pedicel in male, 4.5 times in female; frontal length in profile about 0.7 of facial length; 3 presutural and 3 postsutural dorsocentral setae; frons at narrowest point 0.34– 0.35 of head width in male, 0.38–0.39 in female; gena 0.22–0.24 of eye height in profile; puparium with posterior spiracles raised well above posterior surface.

Description. Body length: 4.5–5.0 mm.

Male. Head with dense whitish pruinosity, fronto-orbital plate pale yellowish and dark gray posteriorly, occiput grayish; frontal vitta velvety brown; antenna brown-black; palpus yellow, narrowly darkened basally. Frons at narrowest point 0.34–0.35 of head width (1.10–1.25 of single eye width); frontal vitta nearly parallel-sided, subequal in width to fronto-orbital plate; frontal length about 0.7 of facial length in profile; parafacial weakly bulged in profile, about 1/2 as wide as postpedicel at middle height in horizontal position (about 2/ 5 in profile); face well excavated, lower margin not warped, about 2/5 as wide as long at level of vibrissa; gena 0.31–0.33 of eye height in horizontal position (0.22–0.24 in profile); occiput weakly bulged. Inner vertical setae parallel, about 3/4 as long as eye height; 2 reclinate orbital setae, anterior seta stronger and about 1/2 as long as inner vertical seta; ocellar setae slightly longer than anterior reclinate orbital seta; 5–6 frontal setae, lowest seta nearly level with base of arista; fronto-orbital plate with fine and rather sparse hairs, not descending below lowest frontal seta; parafacial bare; facial ridge with only a few setulae just above vibrissa; vibrissa inserted level with lower margin of face; occiput with 2–3 rows of fine black setae behind postocular setae and whitish pile. Antenna long, postpedicel about 4 times as long as wide and 7 times as long as pedicel; arista thickened on basal 1/3, 2nd aristomere only slightly longer than wide. Palpus slender, only slightly bulged apically.

Thorax black in ground color, with pale yellowish gray pruinosity; scutum with 5 broad longitudinal vittae, of which median 3 vittae sometimes fused forming a broad median vitta, outer vitta about 2 times as wide as pruinose portion between inner and outer vittae. Prosternum bare; postpronotal lobe with 4 strong setae, 3 basal setae set in a straight line; 3 presutural and 3 postsutural acrostichal setae; 3 presutural and 3 postsutural dorsocentral setae; 1 presutural and 3 postsutural intra-alar setae; 3 supra-alar setae; proepisternum, katepimeron and anatergite bare; 3 katepisternal setae; scutellum with rather dense, fine, erect short hairs, a pair of fine, erect discal setae set closely together, 4 marginal setae, basal and subapical setae subequal in length and about 2 times as long as scutellum, lateral seta subequal in length to scutellum, apical setae very fine, hair-like and parallel to each other. Wing hyaline, tegula black, basicosta dark brown; calypter whitish; halter pale yellowish brown; costal spine about 2 times as long as costal setae; 2nd costal sector haired below; vein M from dm-cu crossvein to bend about 2 times distance between bend and wing margin; dm-cu crossvein weakly concave, slightly longer than last section of vein CuA 1. Legs black, hind tibia sometimes slightly paler on median portion; pulvilli pale yellowish; fore tibia with 2 posterior setae; mid tibia with 1 anterodorsal, 2 posterodorsal and 1 ventral setae; hind tibia with a sparsely set row of anterodorsal setae, submedian seta stronger, 1 strong posterodorsal and 2 short ventral setae, and with 2 preapical dorsal and 1 apical anteroventral setae, no apical posteroventral seta; fore claws and pulvilli subequal in length to 5th tarsomere.

Abdomen black in ground color, with pale yellowish gray pruinosity on anterior 1/3–1/4 of 3rd tergite, 4/5 of 4th tergite and entire 5th tergite, pruinosity thinner on median and posterior portions of 3rd tergite and with somewhat shifting appearance on 4th and 5th tergites; venter with evenly grayish pruinosity. Hairs on dorsum rather sparse, short, fine and suberect, longer on lateral portions and fine and erect on 5th tergite; syntergite 1+2 excavated to posterior margin, with a pair of rather fine median marginal setae and 2 lateral marginal setae; 3rd tergite with a pair of rather fine median discal setae, 2 fine lateral discal setae, a pair of strong median marginal setae and 2 strong lateral marginal setae; 4th tergite with a pair of strong median discal setae, 1–2 strong lateral discal setae and a row of strong marginal setae; 5th tergite with regular rows of strong discal setae and marginal setae. Terminalia: Cerci in dorsal view narrowed from base to basal 1/3 and parallel-sided to apical 1/4, then weakly narrowed to apex, apical portion narrowly separated on distal 1/4, in lateral view weakly narrowed to rounded apex; surstylus in lateral view with dorsal and ventral margins parallel from base to apical 1/2, then dorsal margin curved ventrally to rather rounded apex, apical portion with 3 short and strong spinules.

Female. Differing from male as follows: Fronto-orbital plate slightly paler, with pale yellowish brown pruinosity; frons at narrowest point 0.38–0.39 of head width (1.1–1.3 of eye width); inner vertical seta subequal in length to eye height; outer vertical seta about 1/2 as long as inner vertical seta; 2 subequally long proclinate orbital setae, nearly as long as outer vertical seta; 4 frontal setae; parafacial about 5/7 as wide as postpedicel at mid height in horizontal position (2/ 3 in profile); frontal length about 0.75 of facial length in profile; postpedicel about 4.5 times as long as pedicel; no apical scutellar seta; claws and pulvilli shorter than 5th tarsomere. Terminalia: Sixth tergite narrowly separated mid dorsally into hemitergite, only slightly shorter than 6th sternite, with several strong setae marginally; 7th tergite longer than 6th tergite; 7th abdominal spiracle situated in posteromedian portion of 6th tergite; 7th tergite medially separated into two hemitergites, long quadrate in form, longer than 6th tergite; 8th tergite well developed, nearly quadrate, about 1/4 as long as 7th tergite, without hairs; 8th sternite small, triangular; epiproct absent.

Puparium ( Figs 39–40 ). Length 3.3–5.2 mm, width 1.7–2.3 mm. Brown in color; narrow band of very fine wrinkles or minute spinules on anterior 1/3–1/5 of each segment; spiracular plate black, nearly circular, distinctly raised from pupal surface; 15 spiracular slits raised and surrounding central cicatrix (button); no terminal projection.

Etymology. This species is named for its horse-faced (long-faced) head, from the Latin nouns equus (horse) plus facies (face).

Type material. Holotype male*: Japan, Hokkaido / Tomakomai, Toma- / komai Experimental Forest // ex 10.vi.2015 (emerged) / ex Archips nigricaudana / M. Libra & T. Abe ( TOC 24977) ( HUM).

Paratypes *: 1 male, same data as holotype except date and host, 31.v.2015 (emerged), ex Archips crataegana ( TOC 21835) ( USNM) ; 1 female, same data as preceding, 23.v.2015 (emerged), ex Epinotia exquisitana ( TOC 20837) ( KUM) .

Other specimens examined * (all in HUM): 1 specimen (body mostly broken, sex not determined; head, legs and abdomen missing, with exuvia of puparium), same data as holotype except date and host, 4.vi.2015 (emerged), ex Faristenia geminisignella ( TOC 23368); 1 female (head and left fore leg missing), same data as preceding, 26.v.2014, ex Pseudohedya gradana ( TOC 02882) .

Hosts. Lepidoptera , Gelechiidae : Faristenia geminisignella Ponomarenko. Tortricidae : Archips crataegana (Hübner) ; Archips nigricauda Walshingham ; Epinotia exquisitana Christoph ; Pseudohedya gradana Christoph.

Remarks. This is a micro-oviparous tachinid, laying fully incubated minute eggs with a hard chorion (about 0.18 mm long) on the foliage. The female is probably attracted to damaged or partially eaten leaves and lays eggs on them. Only one larva successfully develops within the host and pupates inside the dead host pupa.

This species is characteristic in its horse-faced appearance, long antenna ( Fig. 29 ) and bare prosternum. The puparium has also characteristically expanded posterior spiracles. Cyzenis albicans ( Fallén, 1810) is also recorded from Hokkaido, Japan (Mesnil & Pschorn-Walcher 1963). The new species resembles C. albicans , but may be distinguished from it by its narrower gena, bare prosternum and absence of proclinate or lateroclinate outer orbital setae in the male. The posterior spiracles of the puparium are raised above the surrounding surface as in C. albicans (see O’Hara & Cooper 1992: 793, figs 24–26), but the spiracular slits are evenly arranged around the cicatrix, situated near the center ( Fig. 40 ).

Figures

FIGURES 13–17. Male and female terminalia of Cyzenis equifacialis sp. nov. (paratypes, Hokkaido, Japan). 13. Epandrium, cerci and surstylus in dorsal view (hairs omitted on epandrium and cerci). 14. Same in lateral view (hairs omitted on epandrium and cercus). 15. Hypandrium, pregonite, postgonite and phallus in lateral view. 16. Female terminalia in lateral view. 17. Same in ventral view (hairs omitted). Scale bars: 0.1 mm.

FIGURES 26–34. Adults of Ctenophorinia grisea Mesnil (Hokkaido, Japan), Blepharipa carbonata Mesnil (Hokkaido, Japan), Cyzenis spp. and Eulasiona zimini (Mesnil). 26. Ctenophorinia grisea Mesnil, habitus in lateral view. 27. Blepharipa carbonata Mesnil, habitus in dorsal view. 28–29. Cyzenis equifacialis sp. nov. (paratype male, Hokkaido, Japan). 28. Habitus in lateral view. 29. Male head in lateral view. 30–31. Cyzenis tetrasetosa sp. nov. (paratype male, Hokkaido, Japan). 30. Habitus in lateral view. 31. Head in lateral view. 32–34. Eulasiona zimini (Mesnil) (Hokkaido, Japan). 32. Female habitus in lateral view. 33. Female head in lateral view. 34. Male head in lateral view.

FIGURES 35–44. Puparia. 35–36. Blepharomyia brevicornis sp. nov. (paratype, Hokkaido, Japan). 37–38. Ctenophorinia grisea Mesnil (Hokkaido, Japan). 39–40. Cyzenis equifacialis sp. nov. (paratype, Hokkaido, Japan). 41–42. Cyzenis tetrasetosa sp. nov. (paratype, Hokkaido, Japan). 43.44. Eulasiona zimini Mesnil (Hokkaido, Japan). 35, 37, 39, 41, 43. Lateral view. 36, 38, 40, 44. Posterior apex in lateral or posterior view.