Xyphandrothrips, Okajima & Masumoto, 2025

Xyphandrothrips gen. nov.

Generic definition. Macroptera (microptera not found so far). Head longer than wide, rarely almost as long as wide, with a pair of postocular setae; often anterior end of cheeks rather bulged and shortly overlapping with eyes. Eyes moderately developed; ocelli variable, often rather small; interocellar and postocellar setae minute. Antenna 8-segmented, rarely 7-segmented; segments VIII not constricted at base, widely and closely joined to VII, rarely completely fused with incomplete suture between these morphological segments; segments III with one (0+1), two (1+1) or three (1+2), segment IV with four (2+2 +1) major sense cones. Mouth cone rounded; maxillary stylets long, reaching eyes, close together at middle; maxillary bridge weak or distinct, usually situated far from base of head, usually narrower than one-fifth of head width in female. Prothoracic five pairs of major setae developed, but relatively short, rarely am reduced; notopleural suture complete. Prosternal basantra and ferna moderately developed; prospinasternum variable; mesopresternum reduced medially, narrowly boat-shaped or divided. Metathoracic sternopleural sutures absent. Fore tarsus with a slender lateral tooth, usually as long as width of tarsus. Fore wings weakly narrowed at middle, with duplicated cilia. Abdominal tergites II–VII each with two pairs of sigmoid wing-retaining setae. Tube relatively short, tapering and straight-sided. Terminal setae usually longer than tube. Males usually show allometric growth and with no pore plate on sternite VIII.

Type-species. Xyphandrothrips conjunctus sp. nov.

Comments. This genus is established for nine species: amamianus sp. nov., cinctus sp. nov., conjunctus sp. nov., formosae sp. nov., karaentae sp. nov., megacephalus sp. nov., pallens sp. nov., septemfidus sp. nov. and vietnamicus sp. nov. It may be closely related to Neandrothrips gen. nov. described above. However, Xyphandrothrips has the two terminal antennal segments widely and closely joined. This is similar to the condition in Hadrandrothrips and Leptandrothrips , with these segments rarely completely fused with an incomplete suture between them. In contrast, Neandrothrips species have these segments distinctly separated. Moreover, the long lateral tooth on the fore tarsus in this genus is peculiar in the ‘ Xylaplothrips -complex’. The sense cone formula is also variable in this genus ( Table 2).

Most species of this genus have been collected from dead plants, therefore they seem to be fungus-feeders.

Key to Xyphandrothrips species

1. Antennae 7-segmented ( Fig. 422 View FIGURES 415–422 ), morphological segments VII and VIII completely fused with incomplete suture between them; distance between metanotal median pair of setae narrower than distance between those setae and anterior margin of metanotum ( Fig. 417 View FIGURES 415–422 ).................................................................. septemfidus sp. nov.

-. Antennae 8-segmented (cf. Fig. 373 View FIGURES 366–373 ); distance between metanotal median pair of setae wider than distance between those setae and anterior margin of metanotum (cf. Fig. 361 View FIGURES 359–365 )............................................................. 2

2. Antennal segment III with two (1+1) sense cones............................................................ 3

-. Antennal segment III with three (1+2) sense cones........................................................... 7

3. Fore wing sub-basal setae S3 expanded.................................................................... 4

-. Fore wing sub-basal setae S3 pointed..................................................................... 5

4. Body bicolored brown and yellow ( Fig. 350 View FIGURES 349–358 ), head, thorax and tube brown, abdominal segments I–IX largely yellowish; hind femora yellow............................................................................ cinctus sp. nov.

-. Body uniformly brown ( Fig. 351 View FIGURES 349–358 ); hind femora pale brown..................................... conjunctus sp. nov.

5. Most of major body setae, including postoculars, five pairs of prothoracic setae and tergal S1 and S2 setae, pointed; eyes relatively small, about one-fifth of head length ( Figs 400–401 View FIGURES 400–407 ).................................. megacephalus sp. n

-. At least prothoracic aa, ml, pa and epim, and S1 setae on abdominal tergites II–VIII expanded; eyes larger.............. 6

6. Head almost as long as wide; postocular setae and pronotal am setae pointed; tube a little longer than 0.5 times as long as head................................................................................. amamianus sp. nov.

-. Head about 1.2 times as long as wide; postocular setae and pronotal am setae expanded; tube much shorter than 0.5 times as long as head............................................................................ formosae sp. nov.

7. Body uniformly brown ( Fig. 358 View FIGURES 349–358 )........................................................ vietnamicus sp. nov.

-. Body bicolored yellow and brown, or yellow and pale brown................................................... 8

8. Head and thorax yellowish brown, tube pale brown ( Fig. 356 View FIGURES 349–358 ); fore femora yellowish ( Fig. 412 View FIGURES 408–414 ), weakly shaded with brown; head about 1.3 times as long as wide in female ( Fig. 408 View FIGURES 408–414 ); maxillary stylets narrower than one-fifth of head width apart from each other at middle in female............................................................... pallens sp. nov.

-. Head, thorax and tube brown ( Fig. 353 View FIGURES 349–358 ); fore femora largely brown ( Fig. 397 View FIGURES 390–399 ); head about 1.2 times as long as wide in female ( Fig. 390 View FIGURES 390–399 ); maxillary stylets about one-fifth of head width apart from each other at middle in female..... karaentae sp. nov.