Key to genera of Scirtothrips genus-group

1. Antennae 6-segmented...................................................................... Drepanothrips

-. Antennae 7 or 8-segmented.............................................................................. 2

2. Antennae 7-segmented................................................................................. 3

-. Antennae 8-segmented................................................................................. 5

3. Antennae widely separated, interantennal projection wider than length of antennal segment I; first ocellar setae long, about 3 times as long as distance between posterior ocelli; pronotum with a pair of long anteromarginal setae........ Kenyattathrips

-. Antennae not widely separated, interantennal projection not wider than length of antennal segment I; first ocellar setae not elongate; pronotum with no long anteromarginal setae........................................................ 4

4. Mesonotal median and submedian setae arising almost in a transverse line; abdominal tergites with many rows of closely spaced microtrichia on lateral thirds; tergal median setae S1 longer than distance between their bases....... Anascirtothrip s

-. Mesonotal submedian setae arising near posterior margin, posterolateral to median setae; abdominal tergites lateral thirds with few microtrichia on sculpture lines; tergal median setae S1 shorter than the distance between their bases..... Parascirtothrips

5. Abdominal tergites IV–VII without rows of microtrichia on lines of sculpture laterally (Fig. 4); fore wing second vein with complete row of about 16 setae................................................................ Scirtidothrips

-. Tergal lateral thirds with closely spaced rows of microtrichia on sculpture lines; fore wing second vein with less than 12 setae................................................................................................... 6

6. Tergal setae S1 and S2 arise laterally closer together than their length; head with ocellar setae pair I absent, no setal pair in front of first ocellus............................................................................ Biltothrips

-. Tergal setae S1 usually close together medially, distant from setae S2; ocellar setae pair I present, sometimes wide apart (absent in some specimens of Scirtothrips malayensis)....................................................... 7

7. Abdominal sternites IV–VI with median two pairs of posteromarginal setae arising in front of posterior margin (Fig. 2)................................................................................................ Cercyothrips

-. Abdominal sternites IV–VI with posteromarginal setae arising at margin......................................... 8

8. Tergite IX with pair of campaniform sensilla present medially........................................... Ajothrips

-. Tergite IX without any campaniform sensilla............................................................... 9

9. Fore wing second vein without setae; pronotum trapezoidal, as long as wide (Fig. 10); sternites with complete posteromarginal comb of microtrichia; [where known, male apterous]................................................ Siamothrips

-. Fore wing second vein with some setae; pronotum transverse, wider than long; sternites rarely with complete posteromarginal comb of microtrichia; [where known, male macropterous]................................................... 10

10. Major setae on pronotum and fore wing tapering and sharply pointed.................................... Scirtothrips

-. Major setae on pronotum and fore wing thickened, parallel-sided and bluntly pointed (Fig. 5).............. Ephedrothrips