Vombisidris satunensis

This species, known only from Thailand, was found nesting in dead twigs hanging on shrub trees. Alate queens were found in two colonies (TH22-WJT-188 and TH22-WJT-214) collected in May 2022, thus mating season of the species might be in the dry season. Both colonies were found in lowland (ca. 100 m a.s.l.) at forest edge.

Identification
Vombisidris satunensis is most similar to Vombisidris harpeza in having yellow body and weakly convex mesosomal outline but it can be separated from V. harpeza by:
 * 1) hairs on head relatively long, simple, sharp at tip (short and blunt at tip in V. harpeza)
 * 2) frontal carina well-defined (indistinct in V. harpeza)
 * 3) in dorsal view, metanotal groove indistinct (broad and shallow groove in V. harpeza)
 * 4) propodeal spine short and straight (relatively long and downcurved in V. harpeza)
 * 5) ratio of petiolar length and height greater (1.94 in V. satunensis; 1.5 in V. harpeza)
 * 6) smaller species (TL 2.64–3.07, HW 0.56–0.63 in V. satunensis; TL 3.50, HW 0.75 in V. harpeza).

This species is quite similar to Vombisidris nahet and Vombisidris renateae in having the long petiole and the yellow body but the new species is distinguished from the latter by short and straight propodeal spine (long and distinctly downcurved in the latter two) and clearly smaller body in average (TL 2.64–3.07 mm, HW 0.56–0.63 mm in V. satunensis; TL 3.4–4.1 mm, HW 0.63–0.71 mm in the latter two).

Vombisidris satunensis is also similar to Vombisidris dryas in having slightly straight propodeal spines. However, V. satunensis is separated from V. dryas by the following characteristics:
 * 1) metanotal groove indistinct (broad and shallow groove in V. dryas)
 * 2) part of subocular groove touching anteroventral margin of eye (not touching in V. dryas)
 * 3) frontal carina long and well defined (short and indistinct in V. dryas).

It is also closely related to Vombisidris xylochos in having the yellow body and the straight propodeal spine. It can be easily separated from V. xylochos by:
 * 1) in profile, petiolar node dome-like or roughly triangular, dorsum roundly convex, without distinctly differentiated dorsal face (petiolar node roughly trapezoidal, with distinctly differentiated dorsal face in V. xylochos)
 * 2) propodeal spine relatively short, about 2 times as long as its width at base (long, 4 times as long as its width at base in V. xylochos)
 * 3) metanotal grove absent (present in V. xylochos)

Distribution based on Regional Taxon Lists
Indo-Australian Region: Thailand.

Nomenclature

 * . Vombisidris satunensis Jeenthong et al., 2023: 106, figs. 1, 2, 4C, 4E (w.q.) THAILAND.

Type Material

 * Holotype worker (THNHM-I-00000246, deposited in ), S Thailand, Satun Province, La-ngu District, Kamphaeng Subdistrict, Urai Thong Cave, 7°10'40"N, 99°49'25"E, 21 May 2022, W. Jaitrong leg., TH22-WJT-188.
 * Paratypes, 13 workers (THNHM-I-00000247 to THNHM-I-00000259, ), 1 dealate queen (THNHM-I-00000260), and 5 alate queens (THNHM-I-00000261 to THNHM-I-00000265), same data as holotype; 12 workers (THNHM-I-00000266 to THNHM-I-00000277, ) and 5 alate queens (TH-NHM-I-00000278 to THNHM-I-00000279, THNHM-I-00000295 to THNHM-I-00000297, ), S Thailand, Satun Province, La-ngu District, Khlong Huai Ba near Khao Kluai Mountain, 6°58'29"N, 99°46'22"E, 22 May 2022, W. Jaitrong leg., TH22-WJT-214.