Eulasiona zimini Mesnil, 1963

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 : 289-292

Eulasiona zimini Mesnil, 1963

( Figs 24–25 , 32–34 , 43–44 )

Diagnosis. A dark-colored species. Male head nearly holoptic, inner vertical setae indistinct ( Fig. 34 ), dichoptic in female, inner vertical setae strong and decussate, outer vertical setae distinct in both sexes; eye densely haired; facial ridge bare except for several short setae above vibrissa; parafacial with 1–2 rows of strong setae; prosternum with several fine hairs on both sides; 3 postpronotal setae in a straight line; 3 presutural and 3 postsutural dorsocentral setae; 2 katepisternal setae; 3 pairs of marginal scutellar setae, apical setae absent; costagial seta strong, extending beyond humeral crossvein; 2nd costal sector bare below; hind tibia with 3 preapical dorsal setae; abdomen with discal setae, sometimes also on syntergite 1+2. Body length: 5.1–5.9 mm. [The female and puparium are described here for the first time.]

Description of female and puparium. Female ( Figs 32–34 ). Head dichoptic, with whitish gray pruinosity, upper fronto–orbital and anterodorsal portion of parafacial dark gray; frons wide, at narrowest point 0.32–0.34 of head width (0.9–1.1 of eye width); frontal vitta about 1/2 as wide as fronto-orbital plate at middle; inner vertical setae strong and cruciate, about as long as eye height; outer vertical seta well developed, about 3/4 as long as inner vertical seta; outwardly directed prevertical seta slightly shorter than outer vertical seta; 2 subequally long proclinate orbital setae, subequal in length to outer vertical seta; 5–7 strong frontal setae, lowest seta nearly level with apex of scape; fronto-orbital plate with several fine hairs outside row of frontal setae; face 0.65–0.68 as long as frons in profile; parafacial about 0.83 width of postpedicel at mid height in horizontal position (0.6–0.7 in profile), with a row of 5–6 down-curved setae which increase in length below; gena 0.32–0.34 of eye height in horizontal position (0.26–0.29 in profile); postpedicel of antenna about 2 times as long as wide and 2.7–3.0 times as long as pedicel; claws and pulvilli of legs shorter than 5th tarsomere, fore claws and pulvilli about 1/2 as long as 5th tarsomere; abdominal dorsum with rather thin, whitish pruinosity on anterior 1/4–1/5 of 3rd to 5th tergites. Terminalia ( Figs 24–25 ): Sixth tergite broadly divided mid-dorsally into 2 hemitergites, without hairs; 6th spiracle on membrane close to anteroventral portion of 6th hemitergite; 6th sternite about 1/3 as long as 5th sternite, of equilateral triangle shape, with a row of some rather strong setae and rather long hairs on posterior margin; 7th spiracle on membrane close to posteromedian portion of 6th hemitergite; 7th and 8th tergites absent; 7th sternite nearly triangular, about 2/3 as long as 6th sternite, with a row of fine hairs; 8th sternite with posterior margin weakly rounded, well narrowed to anterior margin, slightly smaller than 7th sternite; epiproct small, divided medially, each half with a few hairs posteriorly; three spermathecae.

Puparium ( Figs 43–44 ). Length 4.7–6.0 mm, width 1.7–2.5 mm. Brown, posterior margin rather weakly narrowed, surface smooth; posterior spiracles black and small, situated close to each other on raised tubercle of posterior portion; 1–2 small and short spiracular slits at apex.

Material examined*. 13 males, 2 females, Japan, Hokkaido, Tomakomai Experimental Forest, Tomakomai, 24–25 and 27.v.2014, 2.vi.2014, 14.vi.2014, 9.vi.2015, ex Rhopobota naevana [ TOC 01522 (abdomen and legs missing) (1 male); TOC 02020 (1 male); TOC 02091 (1 male); TOC 02513 (1 male); TOC 02531 (1 male); TOC 02609 (1 male); TOC 02743 (1 male); TOC 02773 (1 female); TOC 03024 (1 female); TOC 03274 (1 male); TOC 05048 (1 male); TOC 06325 (1 male); TOC 09197 (1 male); TOC 09605 (1 male); TOC 24483 (1 male)], M. Libra & T. Abe; 1 female (head, legs and abdomen missing, thorax broken), same data as preceding except date and host, 31.v.2015, ex Rhopobota sp. ( TOC 01627); 1 female, same data as preceding except date and host, 3.v.2015, ex Rhopobata sp. ( TOC 23302); 1 female (head missing), same data as preceding except date and host, 31.v.2015, ex Pseudohedya gradana ( TOC 22257); 1 female, same data as preceding except date and host, 24.v.2014, ex Archips crataegana ( TOC 00033), ( HUM, KUM, USNM); 1 puparium, 24.vi.2014, ex Rhopobota naevana ( TOC 03480) ( HUM); 1 male, Hokkaido, Sapporo, Jozankei, 30.v.1965, S. Takano ( CNC); 2 females, Hokkaido, Asahikawa City, 30.i.1967, ex Zeiraphera rufimitrata truncata, K. Kamijo ; 1 female, same locality and host as preceding, ii.1969, K. Kamijo ( KUM).

Hosts. Lepidoptera , Tortricidae : Archips crataegana (Hübner) ; Pseudohedya gradana (Christoph) ; Rhopobota naevana (Hübner) ; Rhopobota sp. ; Zeiraphera rufimitrata truncata Oku ( Shima 1999) .

Remarks. This species was well described by Mesnil (1963) based on a male from Khabarovsk, Russia. Mesnil & Shima (1978) recorded the male also from Japan and described and illustrated the male terminalia.

The genus Eulasiona Townsend has been traditionally classified in the subfamily Dexiinae ( Mesnil 1966, as Eulasionina of Voriini ; Herting 1984, as Voriini ; O’Hara & Wood 2004, as Voriini ), mainly because of the structure of the phallus. However, the molecular analysis of Stireman et al. (2019) placed it in the subfamily Tachininae , close to Phytomyptera Rondani and Graphogaster Rondani. They considered the hinged structure of the phallus in Eulasiona to have independently arisen in this genus and in the Dexiinae . The curvature of the phallus in Eulasiona is weak (not angled but rounded) and it lacks an epiphallus (see Mesnil & Shima 1978), whereas the female terminalia lack the 7th and 8th abdominal tergites and sternites; so far as we know, the 8th abdominal tergite and sternite are never lacking in the Dexiinae . Given the sum of the existing evidence, Eulasiona is moved from the subfamily Dexiinae to an unplaced position within the subfamily Tachininae .

This species is a solitary parasitoid and the female deposits fully incubated eggs close to or on the host. Fully developed larvae appear to kill the host while it is still in the larval stage and pupate within the dead host or very close to it. This behavior is inferred from finding the host’s head capsules, fragments of the host’s body or hairs attached to the tachinid puparia in this study. Shima (1999) recorded a tortricid species as a host of E. zimini , and here we add four additional tortricid species as new hosts.

Figures

FIGURES 24–25. Female terminalia of Eulasiona zimini Mesnil (Hokkaido, Japan). 24. Lateral view. 25. Ventral view. 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.