Ptilocera bergi James 1948
Creators: name: Mason, Franco
name: Rozkošný, Rudolf
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Stratiomyidae
Ptilocera
Ptilocera bergi

description: Ptilocera bergi James, 1948
(Figs 60–61, 84–94)
Ptilocera bergi James, 1948: 202
Ptilocera bergi flavescens James, 1948: 204
Type material. P. b e rg i is based on the female holotype, the male allotype and 246 paratypes (121 3 and 125 Ƥ, cf. James 1948). We examined a series of 41 paratypes (19 3 and 22 Ƥ), 38 of them labelled "Guadalcanal 1944–1945, C. O. Berg/ PARATYPE Ptilocera bergi James [red label, handwritten by James]/ Paratype No. 57309 U.S. N.M. [red label]", in USNM, and 2 Ƥ labelled " Paratype [yellow circular label]/Lunga R. Val., Guadalcanal /Coll. J. Laffoon, X.12.1944/ PARATYPE Ƥ Ptilocera bergi James [handwritten by James] /Pres.by Com. Inst. Ent. B. M. 1950 322", in BMNH. One female paratype (Guadalcanal, 1944–1945, C. O. Berg) also in CNC. The majority of the examined specimens are in perfect condition, only the antennae are missing in one male and antennal flagella absent in 2 males and 3 females.
P. bergi flavescens is based on the female holotype, male allotype and 10 paratypes (8 3, 2 Ƥ). We examined the female holotype labelled: "Bougainville I. 10.iv.1944 W. G. Downs/ Ptilocera bergi flavescens James, det. James 48 [handwritten by James]/ HOLOTYPE Ptilocera bergi flavescens James, 1948, N. E. Woodley 2000", and 3 male paratypes with the same data as the holotype. Condition: mostly perfect, only antennal flagella missing in a pair of paratypes.
Diagnosis. Apical flagellomere brown in males and snow white on apical half in females. Males without any hair patches on the abdominal tergites. Females with silverish patches on tergite 2 and 3 (often partly reduced or absent on tergite 3). Male and female wing usually uniformly brown infuscated, in some specimens with a pale apex.
Description. Male (Figs 60, 84–88). Length (mm): body 8.0–10.1 (n = 9), wing 6.6–8.5 (n = 9). Head. Antenna (Fig. 85) completely dark brown to black, basal flagellomere slightly longer than broad, apical flagellomere about 5.0–5.5 times longer than penultimate flagellomere. Face covered by erect silverish pile except for central area. Thorax black, densely and finely punctuate, scutum in dorsal view mainly black, with more or less distinct, narrow medial stripes and broad lateral stripes consisting of violet iridescent scales. Scattered scales also in space between medial and lateral stripes in presutural area (Fig. 84). Scutellum enlarged, with dense scales mainly along broad lateral margin, four scutellar spines slender, long and slightly upcurved, reddish yellow to brown. Apical scutellar spines 0.6–0.8 as long as scutellum in middle. Wing (Fig. 60) uniformly covered with dense brown microtrichia except proximal 2/3 of alula and sometimes fairly broad apex of wing membrane. Rarely a yellowish transverse streak or somewhat yellowish areas along basal halves of both cubital veins distinct. Calypter brown, margined with brown hairs. Halter light brown or blackish infuscated. Legs brown to black, only basitarsi on mid and hind legs sometimes yellowish. Tarsi golden brown haired.
Abdomen (Fig. 84) dark brown to black, without any hair patches and iridescent scales, finely punctate, with very fine micropile. Sternites brown, with reddish brown short pubescence. Male terminalia (Figs 86–88): Proctiger pentagonal, strongly emarginate proximally, cerci short (Fig. 88), posteromedial lobes of genital capsule well developed, only slightly divergent (Fig. 86). Aedeagal complex abruptly constricted below middle, posterolateral papillae without transverse ridges but with transverse basal rows of short hyaline spines (Fig. 87).
Female (Figs 61, 89–94). Length (mm): body 8.5–11.7 (n = 13), wing 7.1–10.1 (n = 5). Head. Antenna (Fig. 90) mainly dark brown to black, only distal half to two-thirds of apical flagellomere snow white. Basal flagellomere slightly broader than long, apical flagellomere 5.0–5.3 times as long as preceding flagellomere. Frontal index: 0.9–1.3 (avg = 1.2, n = 6). Polished face covered with silverish pile except on facial prominence. Thorax black, densely and finely punctate, entirely covered with very short black pile. Scutum with mainly violet shining scales covering presutural area except large longitudinal stripe in middle and two oval areas between suture and postalar callus on each side (Fig. 89). Scutellum semi-circular, covered with silver to violet scales, four stout spines reddish apically or entirely black, shorter than in male, reaching at most 0.4 scutellum length at middle (Fig. 89). Wing membrane brownish infuscated, only basal cells, alula and sometimes also wing apex partly hyaline (Fig. 61). Calypter including marginal hairs brown to black. Halter brownish to black, rarely paler. Abdomen (Fig. 89) black, with faint bluish reflections, finely punctate. Silverish hair patches mostly subquadrate, rounded or subtriangular on tergite 3 (Figs 91–92) and semicircular, subtriangular or missing on tergite 4. Genital furca with a large median aperture and long wing-like posterolateral projections (Figs 93–94).
Variation. James (1948) tried to separate specimens from the Bougainville Island as a subspecies on the basis of extensively variable characters: the yellowish apices of scutellar spines and mid basitarsi, the irregular yellowish transverse streak on the male wing and a reddish shade of hairs along the longitudinal stripes on the female scutum. We found that these characters are more or less distinct also in populations from Guadalcanal and especially from other Solomon Islands (e.g. from Florida Island). That is why we support Woodley´s (2001) conclusion about the synonymy of P. bergi flavescens. Moreover, in males the apical and posterior margin of the wing may be more or less hyaline or completely brown and the extent of the pale part of the last female flagellomere may be confined to the apical half or less; on the other hand James (1948) recorded a female from Santa Cruz with the last flagellomere completely white. Some distinct differences were also found in the extent of the whitish hair patches on female tergites 3 and 4; in extreme cases they can even be confluent longitudinally (Fig. 92).
Remarks. Woodley (2001, Note 21, p. 333) supposed that the holotype of P. b e rg i was inadvertently labelled as a paratype because the holotype could not be found in USNM. Some males and females designated originally as “ Ptilocera bergi flavescens James, det. James” in USNM were considered to belong to the type series and were discussed adequately by Woodley (2001, Note 22, p. 334).
Material examined. 58 3 and 50 Ƥ (including 19 3 and 25 Ƥ types). Australia: Queensland, Cairns, ix.1920 3 Ƥ, J. A. Kusche, in BPBM. Solomon Islands: vii.–viii.1909 l Ƥ, W. W. Froggatt; 15.i. 1935 1 3, R. J. A. W. Lever, both in USNM; Bougainville Island: type series of P. bergi flavescens (see above). Florida Island: iii.1945 1 Ƥ, G. E. Bohart, in USNM; 15.x. 1966 2 3, 2 Ƥ, M. J. A. de Koster, in ZMAN. Guadalcanal Island: 1944, 9 3, 13 Ƥ, in USNM and 1 Ƥ in CNC; 1944– 1945, 1 3, all C. O. Berg, 0–200 2 3, x. 1973 2 3, 1 Ƥ, N. L. H. Krauss, all in USNM. Callego, Hidden Valley, 10. vii.1965 1 Ƥ,? leg., in BMNH; Honiara, 26.–31. iii.1972 2 Ƥ, R. H. Carcasson; xi. 1973 8 3, N. L. H. Krauss, all in USNM; 17.i. 1974 1 3, N. L. H. Krauss, in BMNH; 0–200 m, xi. 1976 1 3, 0–100 m, xii. 1976 1 3, i. 1977, 1 3, N. L. H. Krauss, in USNM; 15.xii. 1980 1 3, N. L. H. Krauss, in BMNH; Kukum, without date 1 3, 10.vi. 1963 1 3, 10. iv.1964 1 Ƥ, 25.vi. 1964 1 3, M. McQuillan, all in BMNH. Lunga River, ix. 1944 2 3, J. Lafoon, in USNM. New Georgia: Rendova, 1954 1 Ƥ, W. H. Mann, in USNM. Russell Islands: Mbanica Island, 24.xi. 1945 1 3, C. L. Gibson, in USNM.
Distribution. In addition to the examined specimens, James (1948) recorded some further localities on Guadalcanal Island (Malimbu River Valley and Teneru District) and from Santa Cruz Islands. P. b e rg i seems thus to be confined to Australia and the Solomon Islands.
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 8-10, DOI: 10.5281/zenodo.278481