Genus Asianthrips Okajima

Asianthrips Okajima, 2006: 187 . Type species: A. orientalis Okajima, 2006, by monotypy.

Small sized species, wings fully developed or not. Head not elongate, postocular setae well developed, other cephalic setae usually minute; usually one or two (rarely three) minute setae arising within ocellar triangle. Eyes large in macroptera, small in microptera. Ocelli well developed in macroptera. Antennae eight-segmented, segment VIII broadly or narrowly fused to segment VII; segment III with two (1 + 1) or three (1 + 2), IV with four (2 + 2) sense cones; segment III asymmetrical; intermediate segments often with a series of 10–20 setae on ventral surface (cf. figs 58 & 65); campaniform sensilla on segment II situated near apex. Maxillary stylets variable, usually retracted into head capsule, rarely shorter, rather apart from each other; maxillary bridge often present, but very weak. Prothoracic notopleural sutures complete; usual five pairs of setae well developed. Basantra present, but weak; ferna and prospinasternum developed. Fore tarsal tooth usually not developed, rarely developed in males. Metathoracic sternopleural suture absent; mesopresternum fused medially to mesoeusternum, reduced or distinct sutures present between these plates at both sides. Fore wings, if fully developed, weakly constricted medially; duplicated cilia usually present; sub-basal setae usually developed and expanded. Pelta variable in shape. Abdominal terga II to VII each with two pairs of wing-retaining setae at least in macroptera; pore plates absent on male sternite VIII. Tube tapering, shorter than head, straight-sided. Anal setae shorter than tube.

Key to species

1. Antennal segments VII and VIII narrowly fused, segment VIII slender, distinctly constricted basally, rather lanceolate (cf. Fig. 30)................................................................................................ 2

-. Antennal segments VII and VIII widely fused, segment VIII broad, not constricted basally, rather artillery shell-shaped, or cone-shaped (cf. Fig. 37)............................................................................... 3

2. Antennal segment III with three sense cones; body largely yellowish (Fig. 1); antennal segments V and VI bicoloured, brown at distal 2/3, yellowish at basal 1/3............................................................. balianus sp n.

-. Antennal segment III with two sense cones; body pale brown to brown (Fig. 28); antennal segments V and VI uniformly brown................................................................................ vietnamensis sp. n.

3. Body bicolourous yellow and brown, or largely yellow; often largely brown, but abdominal segments bicoloured, segments VI–IX yellowish, segments II–V brownish................................................................. 4

-. Body pale brown to dark brown, abdominal segments unicolourous............................................ 11

4. Abdominal segments II–V brown, VI–IX yellowish................................................... orientalis

-. Abdominal segments largely yellowish.................................................................... 5

5. Head uniformly yellow, or largely yellow.................................................................. 6

-. Head brown to dark brown.............................................................................. 8

6. Maxillary stylets retracted to 1/2 of head or longer (Figs. 94 & 95); abdominal tergite II distinctly shaded with brown (Figs. 15, 16 & 98); mesopresternum and mesoeusternum narrowly fused, width of fusion less than 1/2 of mesopresternum width (Fig. 99)....................................................................................... nobilis sp. n.

-. Maxillary stylets retracted to 1/3 of head or shorter (Figs 109 & 131); abdominal tergite II entirely yellow or weakly shaded with brown antero-laterally; mesopresternum and mesoeusternum widely fused, width of fusion more than 3/5 of mesopresternum width............................................................................................... 7

7. Body largely yellow except for brown tube (Figs 109–111); antennal segments VI and VII each with 3–4 setae on dorsum (Fig. 112); tube about 0.5 times as long as head in female................................................ pallens sp. n.

-. Head largely yellow, but ocellar area and genal areas just behind eyes brownish; mesothorax, pleural regions of metathorax and antero-lateral portions of abdominal tergite II weakly shaded with brown; antennal segments VI and VII each with 5–6 setae on dorsum (Fig. 132); tube about 0.6 times as long as head in female................................... sufflavus sp. n.

8. Prothorax yellow..................................................................................... 9

-. Prothorax brown..................................................................................... 10

9. Mesopresternum and mesoeusternum narrowly fused, with distinct sutures between them at both sides (Fig. 128); antennal segments IV and V each with a series of 7–11 setae arranged in a longitudinal line on ventral surface (Fig. 125), at least in macropterous female......................................................................... setifer sp. n.

-. Mesopresternum and mesoeusternum widely fused, with vestigial short sutures between them at both sides (Fig. 44); antennal segments IV and V do not have such a series of setae (Fig. 43)....................................... bicolor sp. n.

10. Maxillary stylets retracted into middle of head capsule (Figs. 62 & 63); fore wing with duplicated cilia...... dentipes sp. n.

-. Maxillary stylets V-shaped and very short, reaching only to basal collar of head (Fig. 36); fore wing without duplicated cilia.................................................................................. bamboosielloides sp. n.

11. Antennal segment III with two sense cones................................................... borneoensis sp. n.

-. Antennal segment III with three sense cones............................................................... 12

12. Maxillary stylets V-shaped and very short, reaching only to basal collar (= occipital ridge) of head (Figs. 88 & 89)............................................................................................... malayanus sp. n.

-. Maxillary stylets longer............................................................................... 13

13. Abdominal tergites small, tergites III–V much narrower than sternite, narrower than pronotum (Fig. 121).. parvinotus sp. n.

-. Abdominal tergites III–V wider than pronotum............................................................. 14

14. Antennal segment III brown, almost as dark as segment IV, with base yellowish (Fig. 57); antennal segment IV with a series of 15–18 short and stout setae on ventral surface, segment V with 10–12 same setae (Fig. 58), at least in macropterous female........................................................................................ dasycornis sp. n.

-. Antennal segment III yellowish, paler than segment IV; a series of ventral short setae on antennal segments present or absent .................................................................................................. 15

15. Mesopresternum and mesoeusternum widely fused, with short sutures between them at both sides (Fig. 148); head a little wider than long, at least in macropterae (Fig. 145).................................................... taiwanus sp. n.

-. Mesopresternum and mesoeusternum narrowly fused, with long sutures between them at both sides; head almost as long as wide or longer....................................................................................... 16

16. Maxillary stylets long, retracted to eyes (Fig. 72); antennal segment IV with a series of 18–19 short and stout setae on ventral surface, segments V and VI each with 11–13 and 6–8 same setae, respectively (Fig. 74); reticles distinct between eyes............................................................................................... longior sp. n.

-. Maxillary stylets shorter, not reaching eyes; a series of ventral short setae on antennal segments absent; reticles very weak or almost smooth between eyes........................................................................... 17

17. Pelta hat-shaped, with distinct lateral wings (Fig. 142); head almost as long as wide, or a little longer (Fig. 137); antennal segment III entirely yellow; fore femora brown, with apical 1/3 yellow; ocellar region swollen weakly; S1 setae on abdominal tergite IX shorter than S2................................................................ sulawesiensis sp. n.

-. Pelta trapezoid, without distinct lateral wings (Fig. 86); head longer than wide (Figs. 80 & 81); antennal segment III yellow with distal 1/2 shaded with pale brown; fore femora brown, with extreme apices yellowish; ocellar region weakly projected to a cone; S1 setae on abdominal tergite IX longer than S2............................................ magnus sp. n.