Leptandrothrips, Okajima & Masumoto, 2025

Leptandrothrips gen. nov.

Generic definition. Macroptera or microptera. Head longer than wide (cf. Fig. 25 View FIGURES 25–32 ), with a pair of postocular setae. Eyes moderately developed; ocelli rather small, often absent in micropterae; interocellar and postocellar setae minute. Antenna 8-segmented; segment VIII not constricted at base, widely and closely joined to segment VII, these two segments forming a single segment (cf. Fig. 32 View FIGURES 25–32 ); segment III with two (1+1) or three (1+2), segment IV with two (1+1), three (1+2) or four (2+2) sense cones. Mouth cone short and rounded; maxillary stylets rather close together, sub-parallel at middle, reaching postocular setae; maxillary bridge distinct, but often weak, narrower than half of head width. Prothoracic five pairs of major setae developed; notopleural suture complete. Prosternal basantra and ferna moderately developed (cf. Fig. 27 View FIGURES 25–32 ); prospinasternum well developed; mesopresternum transverse, reduced medially, often divided. Metathoracic sternopleural sutures absent. Fore tarsus unarmed (cf. Figs 45 & 46 View FIGURES 41–48 ), often with a very small apical tooth. Fore wings, if present, scarcely narrowed medially, with duplicated cilia. Abdominal tergite II–VII each with two pairs of sigmoid wing-retaining setae at least in macroptera. Tergite IX S1 and S2 setae finely pointed, much longer than tube. Tube usually longer than 0.5 times as long as head, tapering and straight-sided (cf. Fig. 30 View FIGURES 25–32 ). Terminal setae longer than 1.5 times as long as tube. Males without allometric growth and abdominal sternite VIII without pore plate.

Type-species. Leptandrothrips semiflavus (Okajima) comb. nov.

Comments. This genus may be related to the genus Karnyothrips . The species usually have no fore tarsal tooth (cf. Figs 29 View FIGURES 25–32 & 37 View FIGURES 33–40 ), but often have a very small apical tooth instead of lateral tooth. It can be distinguished by having antennal segments VII and VIII closely joined as a single segment outline (cf. Figs 32 View FIGURES 25–32 & 40 View FIGURES 33–40 ), and the prothoracic anteromarginal setae well developed (cf. Fig. 25 View FIGURES 25–32 ). Similar antennal segments are also found in Habrandrothrips gen. nov. and Xyphandrothrips gen. nov., but these two genera have the fore tarsus armed with a distinct lateral tooth. The sense cone formula is variable in this genus, antennal segment III with two or three, and segment IV with two, three or four sense cones ( Table 2). Unfortunately, the feeding habitats of the species are uncertain, but most of the specimens were taken from dead plants and are possibly fungivorous.

Okajima (2006) described three species from both the temperate and subtropical regions of Japan under the genus Apterygothrips . However, they are not closely related to the genus Haplothrips , though Apterygothrips may be more closely related to Haplothrips rather than to both Mesandrothrips and Xylaplothrips . Moreover, the two terminal antennal segments are closely joined as a single segment, and in this character state they can clearly be distinguished from Mesandrothrips and Xylaplothrips . According to the original description ( Ananthakrishnan & Jagadish 1967) and to Pitkin (1976), Apterygothrips fungosus , which was originally described under the genus Xylaplothrips from India, is more similar to this genus rather than Apterygothrips , but further study is needed.

Key to Leptandrothrips species

1. Antennal segment IV with two (1+1) sense cones............................................................ 2

- Antennal segment IV with three (1+2) or (2+2) sense cones.................................................... 5

2. Antennal segment III brown, a little paler than segment IV.................................................... 3

- Antennal segment III yellow to brownish yellow, much paler than segment IV..................................... 4

3. Maxillary bridge much narrower than one-third of head width; ocelli absent in micropterae; tube about 0.65 times as long as head in female........................................................................ zelkobae comb. nov.

- Maxillary bridge about one-third of head width; ocelli present in micropterae, but small; tube about 0.6 times as long as head in female............................................................................. nigrescens sp. nov.

4. All femora largely brown, almost as dark as head or a little paler, tibiae brownish yellow; mesopresternum divided into lateral small triangles........................................................................ robustus comb. nov.

- All femora largely yellow, much paler than head, tibiae yellow; mesopresternum transverse, not divided, narrowly boat-shaped............................................................................. semiflavus comb. nov.

5. Antennal segments III and IV with two (1+1) and three (1+2) sense cones respectively................ indosinae sp. nov.

- Antennal segments III and IV with three (1+2) and four (2+2) sense cones respectively............... inexpectus sp. nov.