Dichaetomyia shinonagai, Couri & Pont & Daugeron, 2010

Couri, Marcia S., Pont, Adrian C. & Daugeron, Christophe, 2010, The Muscidae (Diptera) of New Caledonia 2503, Zootaxa 2503 (1), pp. 1-61 : 30-33

19. Dichaetomyia shinonagai , sp. nov.

( Figs 17–26 )

Holotype. Male holotype, deposited in MNHN, labelled: New Caledonia: Rivière Bleue : P4, 292b, 1– 14.viii.1986, L. Bonnet de Larbogne, J. Chazeau.

Diagnosis. Robust species, body colour completely yellow; scutum and abdomen with no dark marks; legs yellow; fore tibia with a median posterior seta; dorsocentrals 2+3.

Description. General colour. Ground-colour yellow. Head with frons brown, a little reddish towards lunule; fronto-orbital plate brown, silver pollinose; gena brown. Antenna yellow; postpedicel light brown on apical half. Arista brown. Palpus brown. Scutum wholly yellow, with no dark marks. Anterior and posterior spiracles white to yellow, posterior one with black setae on margins. Pleura wholly yellow. Anepimeron with yellow setulae in most males and with yellow and black setulae just below calypters in most the females. Metepisternal hairs pale. Wing yellow tinged. Calypters and halter yellow in both sexes. Wing clear. Legs and abdomen wholly yellow. Setulae on sternite 2 mostly yellow.

Male. Length. Body: 6.5–7.0 mm, wing: 6.0–6.5 mm

Head. Eye with very short and sparse hairs; separated at vertex by the width of the ocellar triangle. Vertical setae not developed. Frontal row with 1 strong pair of setae close to lunula, followed by 2 or 3 other short and thin pairs; reclinate orbitals minute. Antenna inserted at mid level of eye; postpedicel about 2.2 times as long as pedicel. Arista with long plumes. Palpus slightly clavate.

Thorax. Acrostichals 0+1; dorsocentrals 2+3; 2 postpronotals; 1 presutural; 2 intraalars; 2 supraalars; 2 postsupraalars. Notopleuron with two setae, the posterior one a little shorter than the anterior, with or without setulae around anterior seta. Postalar declivity and suprasquamal ridge bare. Scutellum with one long subbasal and one long apical pair of setae, similar in size; no setulae on lateral or ventral margins. Anepisternum with a series of 4–5 long setae and with some fine setae on posterior margin and a short seta at upper anterior angle. Katepisternals 1+2, the upper posterior one very long. Anepimeron with a tuft of setulae above and some scattered setulae on posterior half. Posterior spiracle with a row of setulae on lower and posterior margins. Lower calypter about twice as long as upper one. Wing with stem-vein bare above and vein R 4+5 with 1–2 dorsal and ventral setulae on the node at base. Fore femur with complete rows of posteroventral, posterodorsal and dorsal setae. Fore tibia with a median posterior seta, one dorsal and one posteroventral apical. Mid femur with a row of posteroventral setae, and 3 preapical posterior to posterodorsal setae, the posterodorsal one shorter. Mid tibia with 2 strong posterior setae on middle third, and with a strong apical seta on ventral and posteroventral surfaces, especially the ventral one. Hind femur with a complete anterodorsal row of more or less strong setae, and a row of anteroventral setae that are weaker in basal half, with only short posteroventrals. Hind tibia with one median anterodorsal, 2–3 thin and short anteroventrals on median third, one anterodorsal and one dorsal preapical and one ventral apical.

Abdomen. Tergites 3–5 each with 2–3 lateral pairs of discal setae; tergites 4 and 5 each with a marginal row of setae, complete or interrupted at middle. Sternite 1 bare. Sternite 5 as in Fig. 17 .

Terminalia. Cercal plate a little higher than wide, with stronger setae on upper margin; surstylus slightly surpassing margin of cercal plate ( Figs 18 and 19 ). Aedeagus as in Fig. 20 .

Female. Length. Body: 6.4–7.2 mm, wing: 6.0–6.5 mm

Very similar to the male, differing as follows: frons at vertex about 1/3 of head-width. 4–5 pairs of frontal setae; lower orbital seta very short, 1/4 length of upper orbital. Inner and outer vertical setae developed. Ocellar setae longer than in male. Mid femur with only 1 posteroventral. Hind femur with only 3–4 anteroventrals in apical third, without any trace of posteroventrals. Sternite 1 with a few setulae.

Ovipositor and spermatheca as in Figs 21–22 .

Larva. As in Figs 23 (anterior segments) and 24 (posterior segments); cephalopharyngeal skeleton as in Fig. 25 and posterior spiracle as in Fig. 26 .

Discussion. The species can be easily recognized among the Australasian species of the polita -group by its extensive yellow colour, with no trace of brown vittae or marks on the scutum. In the key to Australian species by Pont (1969a), this species runs to couplet 18 and can be separated from the species in this couplet by the entirely yellow ground-colour. D. shinonagai n. sp. is morphologically close to D. collessi Pont and can be distinguished from it by its wholly yellow abdomen in male and female; at middle of frons in female, a fronto-orbital plate is ¼ of the width of the frontal plate and differs from the wider fronto-orbital plate of D. collessi (cf Fig. 22 in Pont, 1969a); and the scutum is undusted when viewed from above and from behind.

Etymology. The species is dedicated to Dr S. Shinonaga, for his great contribution to the knowledge of the Diptera fauna of New Caledonia and of the Oriental and Australasian Regions in general.

Material examined (all paratypes): MNHN: New Caledonia: Col d’Amieu : Sarraméa, 412 m , 21°34.407S 165°45.674E, 19.xii.2007 – 11.i.2008, piège Malaise, 1 ♀ ( BPBM) ; 11–25.i.2008, 3 ♀; 5–19.xii.2008, 2 ♀; all T. Théry. Côte Est au sud de Hienghène: Vaillé de Que , Hava, affluent de La Tinpindjé, 20 m, forêt littorale dégradée à Cyas , vii–ix.1993, 1 ♂ ( BPBM) , 1 ♀, P. Bouchet. Rivière Bleue: Parc 4, 164d, 4–20.xii.1985, 1 ♀, L.B.dL., J.C.; 290b, 26.v–06.vi.1986, 1 ♂ ( OUMNH) , 3 ♀, L.B.dL., J.C.; 291d, 01–15.ix.1986, 1 ♂, L.B.dL., J.C., A.S.T.; 291e, 01–15.ix.1986, 2 ♂, 5 ♀, L.B.dL., J.C., A.S.T.; 292b, 01–14.viii.1986, 1 ♂, 1 ♀, L.B.dL., J.C., A.S.T; 294a, 11–23.iv.1986, 1 ♀, L.B.dL., J.C.; 295f, 09–26.v.1986, 11 ♀ (1 OUMNH) , L.B.dL., J.C.; 294d, 09–26.v.1986, 1 ♂, L.B.dL., J.C.; 295d, 9–26.v.1986, 1 ♂ ( MNRJ) , L.B. dL., J.C.; 295f, 2 ♀ (2 MNRJ) ; 298c, 20.vi–04–vii.1987, 1 ♀, L.B.dL., J.C.; 299a, 06–20.ii.1986, 1 ♀, L.B.dL., J.C.; 299b, 3 ♀; 300a, 23.i– 06.ii.1986, 2 ♀; 302c, 08–23.i.1986, 1 ♀, L.B.dL., J.C.; 302f, 2 ♀; 303b, 06–20.vi.1986, 2 ♂, L.B.dL., J.C.; 303d, 2 ♀; 303e, 1 ♀; Parc 5, 150 m , 13–28.x.1986, For. Hum./alluvions, L. B. de Larbogne, J. Chazeau, piège de Malaise, 4 ♀, Shinonaga det.; 65a, 04–17.vii.1986, 1 ♂, 1 ♀ L.B.dL., J.C.; 65c, 1 ♀; 168a, 19.xi–4.xii, 1 ♂ ( BMNH) , L.B.dL., J.C.; 168b, 3 ♀; 228a, 25.xi–08.xii.1986, 1 ♀, L.B.dL., J.C., A.S.T.; 228e, 1 ♀; 232b, 20.ii– 02.iii.1986, 2 ♀, L.B.dL., J.C.; 233b, 15–29.ix.1986, 2 ♀, L.B.dL., J.C., A.S.T.; 234b, 29.ix–13.x.1986, 3 ♀, L.B.dL., J.C., A.S.T.; 386a, 16.vi–07.vii.1986, 2 ♀, L.B.dL., J.C., A.S.T.; 386b, 3 ♀; 386c, 4 ♂, 10 ♀; 386d, 3 ♂, 7 ♀; 386e, 2 ♀; Parc 6, 160 m , 18.vii–1.viii.1986, Forêt humide alluvions, L. B. de L. et S. T., 1 ♂, 1 ♀, Shinonaga det. 67a, 07–18.vii.1986, 2 ♀, L.B.dL., J.C.; 186b, 27.x–13.xi.1988, 1 ♀, L.B.dL., J.C., A.S.T.; 187d, 11–27.x.1988, 1 ♀, L.B.dL., J.C., A.S.T.; 187e, 2 ♀; 253a, 15–29.ix.1986, 1 ♀, L.B.dL., J.C.; 275a, 02– 20.ii.1986, 1 ♀, L.B.dL., J.C.; 274a, 20.xii–12.iii.1986, 1 ♀, L.B.dL., J.C.; 386c, 16.vi–07.vii. 1986, 2 ♀; L.B.dL., J.C., A.S.T., 255c, 26.v–06.vi.1986, 1 ♀, L.B.dL., J.C.; 255c, 1 ♀; 256a, 09–26.v.1986, 1 ♂ ( MNRJ) , 6 ♀ (1 OUMNH) , L.B.dL., J.C.; 256b, 3 ♀; 256c, 1 ♀; 257a, 20.vi–04.vii.1986, 1 ♀, L.B. dL., J.C.; 257b, 1 ♂ ( BMNH) , 1 ♀; 257c, 2 ♀; 262c, 1–15.ix.1986, 1 ♀, L.B.dL., J.C., A.S.T.; 263c, 28.x–12.xi.1986, 1 ♂ OUMNH), 386c, 16.vi–07.vii. 1986, 2 ♀ ; L.B.dL., J.C., A.S.T.; 263b, 1 ♀; 266a, 12–27.iii.1986, 2 ♀, L.B.dL., J.C.; 276a, 23.iv–09.v.1986, 1 ♀, L.B.dL., J.C.; 276d, 2 ♀; 386c, 16.vi–07.vii. 1986, 2 ♀; L.B.dL., J.C.; 270a, 20.xii.1985 – 08.i.1986; 1 ♀ ( BPBM) , 386c, 16.vi–07.vii. 1986, 2 ♀; L.B.dL., J.C.; 270b, 1 ♀; 355a, 20– 31.i.1987, 1 ♀, L.B.dL., J.C., A.S.T.; 357a, 31.i–12.ii.1987, 1 ♀, L.B.dL., J.C., A.S.T.; 358b, 15.ii– 13.03.1987, 1 ♂, 2 ♀, L.B.dL., J.C., A.S.T.; Parc 7, 3, 14.viii–01.ix.1986, 2 ♀, L.B.dL., J.C.; 45, 18.vii–01.viii.1986, 1 ♀, L.B.dL., J.C., A.S.T.; 191e, 07–21.xi.1988, 3 ♀ (2 BMNH) , L.B.dL., J.C.; 199a, 01– 15.09.1986, 1 ♀, L.B.dL., J.C., A.S.T.; Maquis sur crête, 28.x–12.xi.1986, 2 ♀, L.B.dL., J.C., A.S.T.; Maquis, Sut. C, 27b, 8–25.xii.1986, 1 ♂, 1 ♀, L.B.dL., J.C., A.S.T.; Maquis sur crête, 438, 07–13.vii.1987, 1 ♂, L.B.dL., J.C., A.S.T.; 437, 03– 16.vi.1987, 2 ♀; L.B.dL., J.C., A.S.T.; 453c, 12–25.ii.1987, 1 ♂, L.B.dL., J.C., A.S.T.; 453d, 1 ♂; Forêt de transition à casuarinacées sur pente, 183, 24.viii–07.ix.1989, 2 ♀, L.B.dL., J.C.; 194d, 7–21.ii.1988, 1 ♀ ( BPBM) , L.B.dL., J.C.; 210b, 28.x–12.xi.1986, 1 ♀, L.B.dL., J.C., A.S.T.; 212b, 20.vi–04.vii.1986, 1 ♀, L.B.dL., J.C., A.S.T.

NSMT (as Dichaetomyia sp. polita -group in Shinonaga et al., 1991): New Caledonia: Col de Pétchécara : 15 km W of Thio, 10.ii.1978, 1 ♂, H. Kurahashi. Hienghène: 21–22.ii.1978, 1 ♀, S. Shinonaga. Hienghène to Bourail: 21–22.ii.1978, 1 ♀, S. Shinonaga .

BPBM: New Caledonia: Canala : 0–5 m, 23.ix.1979, 1 ♂, W. C. Gagné, G.M. Nishida, G.A. Samuelson. Col d’Amieu : 700–800 m, 31.iii.1968, 1 ♂, light trap, R. Straatmann. La Crouen : iii.1959, 1 ♀, N.L.H. Krauss. Mont Panié: 1360 m, 10.x.1967, 1 ♀, J. & M. Sedlacek. Monts Koghis: 450–600 m, 4–6.x.1967, 1 ♂, 1 ♀, J. & M. Sedlacek; 400–600 m, i.1969, 3 ♀, N.L.H. Krauss; 500 m, 23–27.viii.1967, 2 ♀, 27.x.1967, 1 ♀ , M. Sedlacek; 420 m, 21.ix.1979, 1 ♀, W. C. Gagné, G.M. Nishida, G.A. Samuelson. Poindime : 0–50 m, i.1969, 2 ♀, N.L.H. Krauss. Pouébo: 20–100 m, 23.i.1964, 1 ♀, R. Straatman; 23.i.1964, 1 ♀. Yiambi: NE, 1–50 m, 15.x.1967, 1 ♀, J. & M. Sedlacek; 50–500, 14.x.1967, 1 ♂, J. & M. Sedlacek. Loyalty Islands: Lifou: Airport , 26–27.iii.1968, 2 ♀, J.L. Gressitt & T.C. Maa .

MHNG: New Caledonia: Sarraméa : Reserve du Col d’Amieu, 609 m, Malaise trap, 21°34.914S, 165°46.376E, 16–20.vi.2006, 1 ♂, C. Mille; 24.iv–17.v.2006, 1 ♀; collecté sur divers arbres, sur battage, 2– 30.xi.2005, 1 ♀, Cazère, Mille & Katoui .

Distribution. New Caledonia ( New Caledonia, Loyalty Is).

Comments. The species was very numerous in the sorted material. The new species is viviparous, as one single larva was found inside the abdomen, occupying almost its entire internal space. Viviparity is very rare in the Diptera , and has been reviewed by Meier, Kotrba & Ferrar (1999). These authors have recorded a number of cases that have arisen independently within the Muscidae , and they record one case of obligate ovoviviparity in the genus Dichaetomyia , in Dichaetomyia luteiventris (Rondani) , based on an observation by Cuthbertson (1937, cited in Meier et al., 1999: 213).

Figures

FIGURES 17–26. Dichaetomyia shinonagai, sp. nov. 17–20. Male terminalia. 17. Sternite 5. 18. Cercal plate and surstylus, dorsal view. 19. Cercal plate and surstylus, lateral view. 20. Aedeagus, lateral view. 21–22. Female. 21. Ovipositor, dorsal view. 22. Ovipositor, ventral view and spermathecae. 23–26. Larva. 23. Anterior segments. 24. Posterior segments. 25. Cephalopharyngeal skeleton. 26. Posterior spiracle.