Pseudebenia epilachnae Shima & Han

Shima, Hiroshi, Han, Ho-Yon & Tachi, Takuji, 2010, Description of a new genus and six new species of Tachinidae (Diptera) from Asia and New Guinea, Zootaxa 2516, pp. 49-67 : 54-58

Pseudebenia epilachnae Shima & Han , sp. nov.

( Figs. 6−10 , 12−13 , 41−46 )

Male. Head black in ground color, gena below eye pale brown; fronto-orbital plate, parafacial and face with silvery white pruinosity; gena, postorbit and occiput with dark grayish pruinosity, more blackish on upper occiput; antenna black; palpus black. Frons strongly narrowed on posterior 1/2; face about 3/4 as long as frons in profile, about 3/4 as wide as long at level of vibrissae; parafacial narrowed below, slightly more than 1/2 width of 1st flagellomere at middle height; gena about 1/5 of eye height. Inner vertical seta fine, about 3/5 as long as eye height; outer vertical seta indistinct; ocellar seta rather strong, nearly as long as inner vertical seta; fronto-orbital plate bare; 5−8 strong frontal setae, upper 1−2 setae fine and second lowest seta strongest, lowest seta nearly level with base of pedicel; genal dilation wholly with dense long and rather strong hairs; postocular setae long, very close to posterior margin of eye on upper 2/3. Antenna with pedicel bearing a long seta nearly as long as 1st flagellomere; 1st flagellomere about 3 times as long as pedicel; total width of arista including plumosity slightly narrower than 1st flagellomere. Palpus nearly as long as 1st flagellomere.

Thorax black, with thin grayish white pruinosity on posterodorsal portion of postpronotal lobe and notopleural area, grayish brown pruinosity on proepisternum, posterior portion of anepisternum, katepisternum, meron, anatergite and subscutellum. Hairs on dorsum rather dense, fine long and erect, longer on scutellum; 1 presutural acrostichal seta, no postsutural seta; 2 katepisternal setae; distance between bases of subapical scutellar setae about 2.5 times that between basal and subapical setae of corresponding side; apical scutellar seta subequal in length to subapical seta and about 2 times as long as scutellum.

Wing hyaline, weakly tinged with pale brown along veins, the brownish tinge broad and more distinct on basal and anterior area; calypteres translucent pale brownish white, lower calypter darkened marginally, with short fringe. Costa between subcosta and vein R1 about 1/3 as long as that between veins R1 and R2+3; bend of vein M about 3 times closer to wing margin than to dm-cu crossvein; last section of vein CuA1 about 1/2 as long as dm-cu crossvein.

Legs black, with thin grayish brown pruinosity on anterior portions of coxae; pulvilli pale brown. Fore tibia with 2 posterior setae; mid tibia with 1 anterodorsal and 4 posterodorsal setae; hind tibia with a row of anterodorsal setae of irregular length, 4−5 posterodorsal and 3 ventral setae. Claws and pulvilli slightly longer than 5th tarsomere.

Abdomen black, with thin whitish pruinosity on anterolateral 1/3 of 3rd tergite and on 1/2 of 4th tergite. Abdominal dorsum with dense fine and erect hairs; syntergite 1+2 with 1−2 fine lateral discal and 2 strong lateral marginal setae; 3rd tergite with 2 median discal, 2 lateral discal and a row of marginal setae, 2 median marginal setae slightly set forward; 4th and 5th tergites each with regularly set rows of strong discal and marginal setae.

Male terminalia: Pregonite with 2 setae, apical seta slightly shorter than phallus; surstylus rather broad in lateral view, dorsal margin convex near middle and weakly narrowed to blunt apex, without hair on outer surface; cerci in dorsal view nearly parallel-sided on basal 5/6, completely fused and mid dorsal suture obliterated on basal 1/2 and narrowly separated on apical 1/4.

Female. Differing from male as follows: Head with dense silvery white pruinosity on lower fronto-orbital plate, face, parafacial, upper portion of gena and postorbit. Vertex about 2/9 of head width; frontal vitta nearly parallel-sided, about 2/3 as wide as fronto-orbital plate at middle. Inner vertical setae crossed apically, strong, about 3/5 as long as eye height; outer vertical seta about 2/3 as long as inner vertical seta; ocellar seta short and fine, slightly less than 1/3 length of inner vertical seta; 1 outwardly directed prevertical seta, as long as inner vertical seta; 2 proclinate orbital setae, anterior one slightly stronger and subequal in length to inner vertical seta; 3−4 inclinate frontal setae; fronto-orbital plate with a few short fine hairs on inner portion. Pedicel with a long seta at most 1/2 as long as 1st flagellomere; 1st flagellomere about 4 times as long as pedicel. Eye with sparse fine short hairs. Thorax with rather dense whitish pruinosity on median longitudinal portion of presutural scutum, postpronotal lobe and notopleural area, with thin grayish white pruinosity on proepisternum, posterior portion of anepisternum, entire katepisternum, meron, katatergite, anatergite and subscutellum. Calypteres white, lower calypter with short whitish fringe. Mid tibia with a strong v seta; claws and pulvilli shorter than 5th tarsomere.

Female terminalia: 6th tergite weakly sclerotized, divided into two rectangular hemitergites, with a row of hairs on posterior margin; 6th sternite rectangular, longer than 6th tergite, with strong hairs on posterior 1/2; 7th tergite absent, several short hairs on area of 7th tergite; 7th sternite weakly sclerotized, very short, with a row of hairs on posterior margin; 8th tergite absent; 8th sternite of rectangular sclerite, about 1/2 as long as 6th sternite; epiproct rather weakly sclerotized, with many fine and short hairs on posterior margin.

Body length. 5.6−5.8 mm.

Holotype male, Mt. Yongmunsan, Yangpyeong-gun, Gyeonggi-do, South Korea, 17.x.1984 host coll. (parasitized Epilachna quadricollis larva overwintering under ash tree, Fraxinus rhynchophylla Hance ), 13.v.1985 emerged ex mummified host larva, H.Y. Han & J.H. Lee (YSUW).

Paratypes: Same collecting data as the holotype with the following emergence dates: 2 males, 14.v.1985; 1 female, 16−17.v.1985 (BLKU). 1 male, 3 females, 13.v.1985; 1 female, 14.v.1985; 3 males, 6 females, 15.v.1985; 8 females, 16−17.v.1985; 5 females, 18.v.1985 (YSUW). 2 females, Sudo-san, 1000 m, Gyongsangbuk-do, Korea, 1.viii.1977, K. Yamagishi (BLKU).

Biology. The newly reported host species, Epilachna quadricollis (Dieke) ( Coleoptera , Coccinellidae ), is univoltine in Korea feeding on leaves of Fraxinus spp. and occasionally of Ligustrum spp. It is common to see characteristic feeding signs of these beetles on foliage of their preferred host, Fraxinus rhynchophylla Hance. In Gyeonggi-do where most observations were made, pupation and adult emergence are believed to occur from late April to May and oviposition occurs mostly in July. Development from the egg to the 3rd larval instar takes about 40 days, and the 4th larval instar feeds until September, when abscission of Fraxinus foliage begins. Fourth instar larvae overwinter in the 4th larval stadium under fallen leaves.

Most specimens of the type series of Pseudebenia epilachnae were obtained during the survey of parasites of phytophagous coccinellid beetles in Korea conducted by the Asian Parasite Laboratory (USDA). The life cycle of P. epilachnae appears to be well synchronized to that of E. quadricollis . At the end of June, it was observed that many early 2nd instar and a few late 1st instar beetle larvae had 1−3 tachinid eggs attached on their dorsum and these were almost certainly eggs of P. epilachnae . The parasitoid overwinters as a 2nd instar in the overwintering host larva and resumes development the following spring. The late 3rd instar leaves its respiratory funnel and orients itself in the same direction as the host’s body. Soon after this reorientation, it protrudes its unusually long and forked posterior spiracles through the dorso-caudal part of the host’s integument and pupates in this position ( Figs. 45, 46 ). At this time the host body becomes mummified. An adult fly emerges in about 20 days after pupation.

Host. Epilachna quadricollis (Dieke) ( Coleoptera , Coccinellidae ).

Distribution. South Korea.

Etymology. The specific name is taken from the generic name of the host species.

Remarks. This species closely resembles P. f u s c a t a, but may be distinguished from it by its paler lower calypter and almost hyaline wing.

Figures

FIGURES 6 − 10. Male terminalia of Pseudebenia epilachnae sp. nov. 6. Epandrium, cerci and surstylus in dorsal view. 7. Same in lateral view. 8. Hypandrium, pregonite, postgonite and phallus in lateral view. 9. Distiphallus in dorsal view. 10. 5 th sternite in ventral view. Scale, 0.1 mm.

FIGURES 11 − 15. Female terminalia. 11. Female terminalia of Pseudebenia argyrosoma sp. nov. in lateral view. 12. Female terminalia of P. epilachnae sp. nov. in lateral view. 13. Epiproct and cerci of P. epilachnae sp. nov. in dorsal view. 14. Epiproct and cerci of P. t ris etos a in dorsal view. 15. Female terminalia of P. trisetosa in lateral view. Scale, 0.1 mm.

FIGURES 41 − 46. Pseudebenia epilachnae sp. nov. 41. Male head in anterolateral view. 42. Male habitus in lateral view. 43. Female head in anterolateral view. 44. Male habitus in lateral view. 45. Mummified host (Epilachna quadricollis) larva with fly puparium inside. 46. Puparium dissected out of mummified host larva.