Ptilocera amethystina Snellen
Creators: name: Mason, Franco
name: Rozkošný, Rudolf
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Stratiomyidae
Ptilocera
Ptilocera amethystina

description: Ptilocera amethystina Snellen van Vollenhoven, 1857
(Figs 10, 24, 30, 35, 57–58, 74 –81)
Ptilocera amethystina Snellen van Vollenhoven 1857: 92.
Type material. Two syntypes deposited in ZMAN, here designated as lectotype and paralectotype. The lectotype is labelled "Blume, Java [rounded label]/ Ptilocera amethystina v. Voll., Coll. F. M. v. d. Wulp/ Syntype /LECTOTY- PUS Ƥ Ptilocera amethystina Snellen van Vollenhoven, 1857: 92, F. Mason & R. Rozkošný det. 2009" [red label]. Condition: antennae and tarsus of hind left leg absent.
The paralectotype belongs to a different species: "Forsten, Bel Amour/ Ptilocera amethystina v. Voll., Coll. F. M. v. d. Wulp / Syntype / PARALECTOTYPUS Ƥ Ptilocera amethystina Snellen van Vollenhoven, 1857: 92 [red label]/ = Ptilocera continua Gerstaecker, 1857, F. Mason & R. Rozkošný det. 2010". Condition: pedicel and flagellum of both antennae and left hind leg absent, anterior margin of both wings damaged.
Diagnosis. Last antennal flagellomere snow white, long and slender, gradually tapered toward apex. Transverse yellow streak in male wing relatively broad and with less contrast than in other species, quite absent in female wing. Marginal fringe of calypter dark brown to black in both sexes. Abdominal lateral markings longitudinal on tergite 3 and subquadrate on tergite 4 in male, and longitudinal on tergites 2‒4 in female, hair patches on tergite 5 in form of two characteristic subtriangular spots.
Description. Male (Figs 57, 74–78). Length (mm): body 5.9–9.6 (n = 48); wing: 4.8–9.6 (n = 48). Head. Lower frons shining dark brown, with transversely oval silverish tomentose spot divided by a median black line. Scape brown, pedicel and flagellomeres 1–2 pale brown, both blackish haired, forming oval complex provided with sensory pits and covered with short brownish pile. Basal flagellomere slightly longer than broad, apical flagellomere snow white, slender, at most pale brown basally, as long as 5 preceding flagellomeres combined and at least 6 times as long as subapical flagellomere (Fig. 75).
Thorax black, finely punctuate, with scales in colour changing from silver, green and blue-green, depending on angle of light, arranged in four longitudinal stripes on scutum, two broadly separated median and broader lateral (=notopleural). Scattered scales also between medial and lateral stripes in presutural area, medial stripes interrupted beyond transverse suture, distinct as elongate triangular spots touching base of scutellum (Fig. 74). Dense scales distinct along margin of scutellum, middle scutellar spines reaching 0.5–0.6 length of scutellum, usually with pale tips. Yellowish transverse streak on wing more or less distinct, relatively broad and fairly diffuse, from apical part of discal cell and continuing along first branch of cubital vein. Wing microtrichia only indistictly reduced in basal cells, alula and basal part of anal cell (Fig. 57). Calypter brown, with long dark brown hair fringe. Slender basitarsus of mid legs sometimes reddish brown, other part of legs usually dark brown to black.
Abdomen dark brown to black, finely punctuate, with large silverish hair patches on tergites 3–5 (Fig. 74). Medial process of genital capsule with divergent posterior lobes (Fig. 76), posterolateral papillae of aedeagal complex without transverse ridges and hyaline flat spines at bases (Fig. 77). Aedeagal apodeme rounded proximally.
Female (Figs 10, 24, 30, 58, 79–81). Length (mm): body 6.9–11.7 (n = 34); wing: 6.4 –10.1 (n = 34). Head. Frontal index 1.3–1.6 (avg = 1.4, n = 27). Basal flagellomere brownish, much broader than in male, almost quadrate in lateral view, projection on flagellomere 2 about as long as swollen basal complex (pedicel + 2 basal flagellomeres), other projections up to twice as long, apical flagellomere four times as long as broad. Last flagellomere 1.6–3.3 times as long as preceding flagellomere. Penultimate flagellomere usually white to pale yellow, rarely darkened (Fig. 80). Scutum black, finely punctate, with pattern consisting of two pairs of pink to green and violet, parallel stripes usually being less conspicuous than in male (Fig. 79). Scutellum flattened, subquadrate, with broad margin of shining, mainly silverish scales, stout and short brown scutellar spines at most half as long as scutellum at middle. Wing (Fig. 58) extensively brown infuscated, transverse yellowish streak not distinct, microtrichia absent in basal part of wing as in male but sometimes also in a narrow longitudinal stripe along middle of posterior cubital cell. Calypter brown, with long blackish fringe as in male. Legs mainly brown with brown pile. Abdomen black, with bluish reflections, finely punctate, with well defined vertically oriented hair patches of silverish pile on tergites 2–5 (Fig. 79). Genital furca as in Fig. 81.
Variation. In addition to size (see above) both sexes may vary in darkening of both basal flagellomeres, density of scales in longitudinal stripes on scutum and the extent of abdominal hair patches. The last flagellomere may rarely be slightly brownish basally (Fig. 10). The penultimate flagellomere is usually brown in males and snow white to yellow in females but de Meijere (1914) mentioned two females with a dark penultimate flagellomere from Sumatra. Especially females usually have white frontal spots of a slightly different size and shape, tips of scutellar spines may be more reddish.
Remarks. The taxonomic status of this species is fixed by the lectotype designation because the second of the original syntypes belongs to a different species (P. continua). Brunetti (1907, 1920, 1923) apparently had no authentic material available. The diagnostic characters of this species were unambiguously defined by de Meijere (1911, 1914). Edwards (1915) erroneously considered this species to be a synonym of P. continua. The male with a white last flagellomere from Sumatra identified as Ptilocera sp. by Kertész (1916) very probably represents a male of P. amethystina.
Material examined. 33 3, 38 Ƥ (including female lectotype). Cambodia: 1 Ƥ, Bigot coll., in BMNH; 1 Ƥ, Stevens, in ZMHB. Indonesia: Java: Djampang Mts, Bibidjilan, 15.iii. 1938 1 3; Djampang Tengah, 15. iv.1938 1 Ƥ; both E. le Moult, in BMNH, 24. iv.1939 1 Ƥ, 11.x. 1939 1 3, 28.xi. 1939 1 3, 2Ƥ, 24. i.1940 4 Ƥ, 8.ii. 1940 2 3, 2. iii.1940 1 Ƥ, 25.iii. 1940 1 3, 24. iv.1940 1 Ƥ, 1.vi. 1941 1 3, 4.xi. 1941 1 3; Gunug Pangrango, 4. iv.1939 1 Ƥ, all in ZMAN. Gunug Tentang, 15.iii. 1938 1 3, E. le Moult, in BMNH; Ordjoeng Genton Bay, ix. 1936 1 3, Penandjoeng [=Penandjon] Peninsula, vii.1936 1 Ƥ, Preanger [=Priangar], 29. iii.1939 1 Ƥ, 15.v. 1939 1 3, 4. xi.1941 1 Ƥ; Soekaboemi [=Sukabumi], 15. v.1926 1 Ƥ, E. le Moult, in BMNH; Soekaboemi [=Sukabumi], Gedek Helling, 10. v.1941 1 Ƥ; Soekaboemi [=Sukabumi], Djampang Kidoel, 1000–1500 ft, 15.xii. 1939 1 3; Tjimerangs, 4. v.1915 1 Ƥ, ii. 1937 1 3, 1 Ƥ; Wynkoopsbay, ix. 1936 1 3, xii. 1936 5 3, 5 Ƥ, ii. 1937 1 3, 3 Ƥ, 15.xii. 1937 1 3, 1 Ƥ; all J. M. A. van Groenendael, all in ZMAN. Kalimantan: 2 3, 1 Ƥ, in MSNG. Si-Pora [=Sipura] Island, 1 3, A. Maas; Sumatra: 1 3, in MSNM (Bezzi Coll.). Lubuksikapink Westkust, 450 m, 1926 1 3, both E. Jacobson, in ZMHB. Tanjung Andalas, 15.v. 1914 1 3, J. M. A. van Groenendael, in ZMAN. Tanjung Morawa, Deli Serdang, 1 Ƥ, in RMNH. Laos: Sayaboury [=Xaignabouli] Province; Sayaboury, 30. vi.1965 1 Ƥ, in BPBM. Malaysia: Sabah: 19 km N of Kalabakan, Forest Camp, 17. x.1962 1 Ƥ, K. J. Kuncheria; 21.xi. 1962 1 3, 21.xi. 1962 1 3; Malaise trap, 12. xi.1962 1 Ƥ, 13.xi. 1962 1 3, 1 Ƥ, Y. Hirashima; all in BPBM, Bettotan nr. Sandakan, 15.viii. 1927 1 3; Poring Springs, 1600 ft, 6.v. 1973 1 3, K. M. Guichard, both in BMNH. Sarawak, Nanga Pelagus near. Kapit, 180–585 m, 7.VIII. 1958 1 3, T. C. Maa, in BPBM. Selangor: Genting Tea Estate, Genting Sembah forest, 2000 ft, 24.xii. 1972 1 3, in BMNH. Myanmar: Nam Tamay valley, 3000 ft, 27°42´N, 97°54´E, 26. viii.1938 1 Ƥ, R. Kaulbaek, in BMNH. Thailand: Chon Buri: Ban Bang Phra, 6.iii. 1968 2 3, M. D. Delfinado, in BPBM; Phuket: Kao Phra Thaew National Park, 1250–2000 m, 08°0.672´N 98° 21.07 E, 15.iv. 2001 1 3, H. Stuke, in FSMU; Trang: Forest Research Station, Khao Chong trail, 75 m, 7°33´0´´ N, 99°47´25´´ E, 7. ii.2005 1 Ƥ, D. Yanega, in UCR. Vietnam: Taynynh [=Tay Ninh], 21. x.1923 1 Ƥ, R. Vitalis de Salvaza, in IRSNB.
Distribution. From Myanmar through Thailand, Laos and Cambodia to Vietnam, from Malaysia known in the continental part but also in Sabah and Sarawak, in Indonesia recorded from Sumatra, Java and Kalimantan. The published records from Java and Sumatra (de Meijere 1911, 1914; Enderlein 1914) are apparently correct. The occurrence in Sulawesi has not been confirmed by recent materal. A record from Sulawesi by Snellen van Vollenhoven (1857) is based on a misidentification (see comments on the paralectotype above) and actually refers to P. continua. Records from the Philippines published by Osten Sacken (1882) under P. amethystina (cited by many subsequent authors) very probably represent P. continua.
description: Published as part of Mason, Franco & Rozkošný, Rudolf, 2011, A review of the Oriental and Australasian Ptilocera species (Diptera: Stratiomyidae), pp. 1-49 in Zootaxa 3007 on pages 6-7, DOI: 10.5281/zenodo.278481