Platypalpus seeluang, Grootaert & Shamshev, 2006

Grootaert, Patrick & Shamshev, Igor, 2006, The genus Platypalpus Macquart (Diptera: Hybotidae) from Northeast Thailand with comments on the species groups in the Oriental region, Journal of Natural History 39 (47), pp. 4031-4065 : 4055-4059

Platypalpus seeluang sp. nov. (male and female)

( Figures 22–26 )

Etymology

The name ‘‘seeluang’’ refers to the yellow colour of the body of this species. ‘‘See luang’’ means ‘‘yellow colour’’ in Thai.

Diagnosis

Almost wholly (including legs) yellow species; head black, with one pair of vertical bristles, antenna with scape and pedicel brown, postpedicel wholly yellow, arista brown, 1.5 times as long as postpedicel, palpus small, yellow; humerus with one minute bristle, acrostichal and dorsocentral bristles two-serial; tarsomere 5 of fore leg black, tarsomeres 3–5 of mid and hind leg darkened, mid femur with a row of posteroventral bristles, mid tibia with long pointed spur.

Material examined

Holotype: male, Thailand: Loei province, Na Haeo , FIRS, 10–18 November 2003 (Malaise trap 3), leg. P. Grootaert and Siriluck Intarasri. Paratypes (arranged in dates): one female, 22–29 May 2003 (4); one female, 29 May to 5 June 2003 (3); two males, two females, 29 May to 5 June 2003 (4); one male, three females, 5–11 June 2003 (4); one female, 9–15 August 2003 (3); two females, 15–22 August 2003 (4); one female, 22–29 August 2003 (3); one female, 22–29 August 2003 (4); three females, 29 August to 4 September 2003 (3); two females, 29 August to 4 September 2003 (4); one female, 4–10 September 2003 (2); one female, 4–10 September 2003 (427); four females, 10–23 September 2003 (3); four females, 10–23 September 2003 (4); one male, 23–30 September 2003 (2); two females, 23–30 September 2003 (3); three females, 30 September to 15 October 2003 (3); two males, three females, 30 September to 15 October 2003 (4); five males, 15–22 October 2003 (3); two females, 15–22 October 2003 (4); eight females, 22– 31 October 2003 (3); three males, 22–31 October 2003 (4); two females, 31 October to 10 November 2003 (3); three females, 31 October to 10 November 2003 (4) (total: 15 males, 48 females; sex ratio: 1:3.2).

Male

Body length 3.1–3.3 mm; wing length 2.9–3.0 mm.

Head. Black in ground-colour. Occiput finely greyish pollinose, subshining, clothed with pale hairs, with two short black verticals (rather closely set). Ocellar tubercle with two short fine bristles. Frons greyish pollinose, narrow, about 1.5 times as wide as anterior ocellus, almost parallel-sided, somewhat widened before ocellar tubercle. Face somewhat narrower and paler pollinose than frons. Antenna ( Figure 22 ) with scape and pedicel brown, postpedicel yellow, arista brown. Postpedicel small, nearly 1.5 times as long as wide and four times shorter than arista. Palpus ( Figure 23 ) small, yellow, ovate, pubescent, with moderately long, yellowish, subapical bristle.

Thorax. Wholly yellow, largely subshining, finely greyish pollinose, sternopleuron shining. Humerus well prominent, with one minute bristle. Mesonotum with black bristles, including two notopleurals (anterior one shorter and thinner), one postalar (shorter than posterior notopleural), and four scutellars (inner ones much longer and stronger); some scattered setulae present behind humerus, in notopleural depression and on supraalar space. Acrostichals very short, arranged in two close, more or less regular rows, distinct throughout. Dorsocentrals subequal in length to acrostichals (except for one pair of longer prescutellars), arranged in two irregular rows. Anterior and posterior spiracles yellow.

Legs. Almost wholly yellow; tarsomere 5 of fore leg wholly black, mid and hind leg with tarsomeres 3–5 becoming gradually darker (from 3rd to 5th). Fore femur incrassate, with moderately long yellow to brownish yellow antero- and posteroventral hair-like setae. Fore tibia spindle-like, with short brownish dorsal bristles and yellow hair-like ventral setae extending on basal tarsomeres. Mid femur incrassate, somewhat thicker, than fore femur, with a row of brownish posteroventral bristles beyond rows of black spinules. Mid tibia with long pointed apical spur. Hind femur with rows of short, yellowish antero- and posteroventral bristles. Hind tibia with some more prominent bristly hairs in apical part.

Wing. Hyaline, with one long black basicostal bristle. Vein M1+2 somewhat bowed in apical part but parallel to R4+5 near wing-apex. Crossveins m-cu and r-m separated. Vein CuA2 straight, at right angle to A1. Squama yellow, pale fringed. Halter pale yellow.

Abdomen. Concolorous with thorax, mostly with scattered yellowish setae, pregenital segments with long yellowish bristles.

Terminalia. Rather small, rounded, brown, rotated 90 °. Left epandrial lamella ( Figure 25 ) subtriangular, with moderately long bristles. Right epandrial lamella ( Figure 26 ) rather subrounded, with several long bristles on upper margin. Right surstylus small, with rounded apex, bearing several short bristles on inner side subapically. Cerci ( Figure 24 ) rather subrectangular, moderately long, pubescent, with scattered long bristles; left cercus somewhat broadened in apical part. Hypoproct ( Figure 24 ) small, plate-like, not extending beyond apices of cerci.

Female

Body length 3.3–3.7 mm; wing length 3.1–3.3 mm.

Abdominal tergites 2–5 with brownish rectangular spots separated by yellow median space. Otherwise as in male except for sexual differences. Cerci brown.

Distribution

Thailand.

Remarks

P. seeluang sp. nov. is most similar to P. dolichopeza Frey described from the Philippines ( Frey 1943). However, the new species can be readily distinguished from it by its wholly yellow thorax and many other characters.

Key to Platypalpus species from Thailand

1. Yellow species; thorax at least partly yellow in ground-colour...... 2

– Black species; thorax wholly black in ground-colour........ 10

2. Two pairs of vertical bristles. Head wholly yellow. Proboscis long, almost as long as head is high. Mesonotum with brownish median vitta. Acrostichal and dorsocentral bristles multiserial, hardly separated. Tarsomeres 3 and 4 of fore leg flattened................ P. hualuang sp. nov.

– One pair of vertical bristles. Head usually wholly black. Proboscis rather short, at most half as long as head is high. Mesonotum wholly yellow or with brownish spots. Acrostichal (if present) and dorsocentral bristles two-serial. Fore leg with slender tarsomeres................... 3

3. Humerus well prominent. Frons above antennae nearly 1.5 times as wide as anterior ocellus. Postpedicel short, 1.5 times longer than wide. Arista black. Hind tibia with long pointed spur. Tarsomere 5 of fore leg wholly black, mid and hind leg with tarsomeres 3–5 becoming gradually darker, otherwise legs yellow................. P. seeluang sp. nov.

– Humerus small, hardly prominent. Frons very narrow, above antennae narrower than anterior ocellus. Postpedicel elongate. Arista white. Mid tibia with hardly prominent flattened apical spur. Legs yellowish to brownish yellow, lacking distinct pattern.................... 4

4. Mesonotum wholly yellow................ 5

– Mesonotum with two more or less distinct brownish spots near postalar calli.. 6

5. Thoracic pleura wholly yellow. Occiput with small yellowish spot near mouthopening laterally, including jowls. Abdominal sternites 5 and 6 with ordinary setae................. P. gaemluang sp. nov.

– Thorax with sternopleuron and hypopleuron largely brown to dark brown (yellow in upper posterior corner and in upper third, respectively). Occiput wholly black. Abdominal sternite 5 with two, sternite 6 with four very long closely set bristles................ P. phomyaaw sp. nov.

6. Mesonotum with two ovate brownish spots extending from base of scutellum to level of posterior notopleural bristle. Abdominal sternite 4 with median brown tubercle bearing tuft of short brown setae........ P. fai sp. nov.

– Mesonotum with smaller spots extending nearly one-third of distance between base of scutellum and posterior notopleural bristle. Abdominal sternite 4 unmodified, with ordinary setation.............. 7

7. Mid femur stout, nearly 2.0 times broader than fore femur....... 8

– Mid femur narrower, nearly 1.5 times broader than fore femur...... 9

8. Postpedicel long, 5.0 times longer than broad. Sternopleuron yellow in upper posterior corner............. P. nuadkhao sp. nov.

– Postpedicel shorter, 4.0 times longer than broad. Sternopleuron wholly brown............... P. isaanensis sp. nov.

9. Anterior spiracle brown. Fore tibia and tarsus darkened. Male: terminalia with hypoproct not extending beyond apices of cerci, with two spine-like extensions............... P. siamensis sp. nov.

– Anterior spiracle yellow. Fore tibia and tarsus yellow. Male: terminalia with hypoproct extending far beyond apices of cerci and overlapping apical part of right epandrial lamella, broadened and rounded at apex, lacking spine-like extensions................ P. thaicus sp. nov.

10. One pair of vertical bristles. Humerus small, hardly prominent. Frons very narrow, above antennae narrower than anterior ocellus. Arista white. Mid tibia with hardly prominent flattened apical spur ( P. albiseta -group). Antenna wholly brownish, postpedicel 5.0 times longer than wide, arista nearly 2.5 times longer than postpedicel. Legs almost entirely brownish yellow, tibiae rather brownish. Fore femur with two longest brownish bristles in posteroventral row. Mesopleuron largely pollinose, only sternopleuron shining...... P. seedam sp. nov.

– Different combination of characters....... other Platypalpus species

Figures

Figures 22–26. Platypalpus seeluang sp. nov., male. (22) Antenna. (23) Palpus. (24) Epandrium with cerci and hypoproct. (25) Left epandrial lamella (lateral view). (26) Right epandrial lamella (lateral view). Scale bar: 0.1 mm.