Ptecticus thailandicus, Rozkošný & Courtney, 2005

Rozkošný, R. & Courtney, G. W., 2005, New Records Of Ptecticus Species From Thailand Including Description Of A New Species (Stratiomyidae, Diptera), Acta Zoologica Academiae Scientiarum Hungaricae 51 (4), pp. 343-348 : 344-347

Ptecticus thailandicus sp. n.

( Figs 1–6 )

Holotype: m, Thailand, Khao Yai National Park , Khao Kheo , 14°22´N, 101°24´E, 952 m, Malaise trap, 9–23 June 2001, J. PHASUK & K. DAMRAK leg., in the collection of the Faculty of Science , Masaryk University, Brno, Czech Republic ( FSMU).

Paratypes: 3 mm and 2 ff with the same locality labels but with date 1–17 April 2001. 2 mm and 1 f in FSMU, and 1 m and 1 f in the National Insect Collection , Entomology and Zoology Division , Department of Agriculture, Chatuchak, Bangkok, Thailand .

Diagnosis: Upper frons and vertex shining black, thorax uniformly ochre yellow, legs predominantly yellow but last two tarsomeres on fore and mid tarsi black as well as hind tibia and greater part of hind basitarsus, rest of hind tarsus snow white. Abdomen yellow with dark transverse patches at anterior margins of tergites 2–5.

Description: m. Head semiglobular in lateral view, ocellar triangle distinctly prominent, frontal callus rounded but relatively high in profile, barely lower than width of fore tibia in distal part. Upper frons and vertex shining black, finely punctate, ocellar triangle also black, upper frons gradually tapering towards frontal callus, slightly broader than anterior ocellus just above it. Frontal index (length between frontal callus and anterior ocellus: width just above frontal callus) 4.20–5.75. Occiput completely black. Frontal callus striking whitish yellow, face and antenna ochre yellow, proboscis somewhat paler. Basal antennal segments shining, pedicel with subtriangular and well defined inner projection, flagellar complex about as high as long and transversely cut distally, slightly rhomboid, arista brown. Pubescence of head mostly erect, predominantly yellow, short above antennae, on basal antennal segments and on face, though long and partly brownish on upper frons, ocellar triangle and vertex. Postocular hairs very dense and appressed, yellowish brown.

Thorax uniformly ochre yellow including scutum, scutellum and mediotergite. Thoracic pubescence predominantly yellow, chiefly erect, moderately long and dense on scutum and combined with very short, dense and blackish hairs on prescutellar area and scutellum. Longest pale hairs above fore coxae and on laterotergites, central area of anepisternum extensively bare.

Wing very finely tinged with yellowish brown, costal margin including pterostigma yellow. Anterior crossvein arising at origin of R 2+3, R 2+3 almost twice longer than R s, virtually parallel to R 1. Upper proximal margin of discal cell slightly arched, posterior crossvein well developed, above half 5 = female terminalia in dorsal view, 6 = female genital furca as long as anterior one. All veins M 1 to M 3 slightly sinuate, so that M 3 is not parallel to M 2, its apical part equalling length of anterior crossvein wanting. Postcubitus developed as a visible and yellowish pigmented vein only in its basal half, continuing mainly as a hyaline wing fold, absent apically. Halteres completely ochre yellow, each posttegula with a tuft of fine golden yellow hairs. Fore and mid legs ochre yellow, only last two tarsomeres on both legs brown, pubescence inconspicuous, chiefly appressed, golden yellow, on tarsomeres more brownish dorsally, semi-appressed and short, brushlike ventrally. Dorsal hairs on last two tarsomeres black. Tibia-basitarsus index of fore leg 1.20–1.42. Hind coxa, trochanter and femur uniformly yellowish brown, hind tibia and hind basitarsus (except extreme distal apex) black and black haired, rest of hind tarsus completely white and purely whitish haired.

Abdomen ochre yellow, with transverse dark patches on tergites 2–5. Dark bands narrowly separated from anterior margins of segments and reaching about middle of segments from their distal margins but distinctly broader on tergites 4 and 5; not reaching lateral margins of tergites. Venter uniformly yellowish brown. Abdominal pubescence mostly golden yellow, long and erect basally and laterally, semi-erect ventrally and very dense and chiefly appressed dorsally, dark brown to black on dorsal dark parts.

Male terminalia ( Figs 1–4 ) yellow, aedeagal complex more or less darkened. Proctiger subtriangular, cerci short, epandrium without surstyli, dilated towards proximal margin. Ventral synsternite with two medial lobes on distal margin. Gonostylus somewhat swollen in middle, pointed apically on inner side. Aedeagal complex simple, tubelike but flattened apically and broadened proximally, without flat proximal apodeme.

Length: body 8.6–10.8 mm, wing 7.7–10.4 mm.

f: As in male but with a broader upper frons and species-specific female terminalia. Deeply shining black upper frons relatively broad even in comparison with majority of species of the genus: about 4 times broader than anterior ocellus just above frontal callus, frontal index 2.00–2.18. Tibia-basitarsal index of fore leg 1.30–1.32. Hind basitarsus usually entirely black (including its apex), abdominal spots sometimes partly reduced. Female terminalia ( Figs 5–6 ): apical cercal segment unusually short, barely 1.5 times as long as broad at base, markedly shorter than basal segment. Genital furca delicate and almost hyaline, basal part with oval aperture, posterolateral appendages slender, posteromedial projections absent.

Length: body 8.0–8.5 mm, wing 7.5–7.7 mm.

Discussion: Some colour characters seems to be variable. The black hairs covering two distal tarsomeres of fore and mid legs may be partly extended especially to the dorsal surface of flagellomere (tarsomere 3 in males in particular), the pale distal part of the hind basitarsus may be completely reduced or extended nearly to the distal third. The size and extent of the abdominal patches also show considerable variation. In both sexes they may be, in extreme cases, reduced on abdominal segments 2 and 3, being visible as mere dark medial patches in the middle of segments.

P. thailandicus sp. n. externally resembles the recently described P. temasekianus ROZKOŠNÝ et KOVAC, 2003 , which is based on a male holotype from Singapore. However, the upper frons, vertex and occiput (the medial sclerite) are clearly yellowish brown in the latter species and not deep black and also structures of the male terminalia show some distinct differences (the posteromedial process of synsternite is tripartite, the adeagal complex is slender and provided with a long and flat proximal apodeme in P. temasekianus ). The female of P. temasekianus is not known.

NEW RECORDS OF ADDITIONAL PTECTICUS SPECIES IN THAILAND

Figures

Figs 1–6. Ptecticus thailandicus sp. n., male and female terminalia: 1 = male terminalia in lateral view, 2 = aedeagus, 3 = epandrium, proctiger and cerci, 4 = synsternite and gonostyli in dorsal view,