Lepisiota bicolor Jarernkong et Jaitrong, 2023

Jarernkong, K., Kongmee, M., Pinkaew, N. & Jaitrong, W., 2023, Three new species of the ant genus Lepisiota Santschi, 1926 (Hymenoptera: Formicidae) from Thailand, Far Eastern Entomologist 468, pp. 1-15 : 3-6

Lepisiota bicolor Jarernkong et Jaitrong , sp. n.

https://zoobank.org/NomenclaturalActs/ DA17447B-BCB8-4ED6-840B-FA96B4CED337

Fig. 1

TYPE MATERIAL. Holotype – worker (THNHM-I-24825, THNHM), N Thailand: Chiang Rai Province, Muaeng District, Pong Nam Ron Village, 21.X 2018, W. Jaitrong leg., WJT211018-15. Paratypes: 13 workers (THNHM-I-24826 to THNHM-I-24838, THNHM), same data as holotype.

NON-TYPE MATERIAL EXAMINED. Seven workers (THNHM-I-24839, THNHM-I-26842 to THNHM-I-26847, THNHM), from W Thailand: Tak Province, Umphang District, 21.X 2018, W. Jaitrong leg., TH15-WJT-46.

DESCRIPTION. Worker ( Fig. 1 ).

Measurements and indices. Holotype: HL 0.56, HW 0.46, EL 0.13, SL 0.32, ML 0.69, FeL 0.66, PL 0.29, PH 0.23, CI 82, SI 135, EI 28, FeI 70.

Paratypes (n = 13): HL 0.52–0.56, HW 0.46–0.49, EL 0.13–0.16, SL 0.62–0.66, ML 0.66–0.75, FeL 0.66–0.69, PL 0.26–0.33, PH 0.19–0.23, CI 82–93, SI 126–142, EI 28–35, FeI 66–75.

Head: in full-face view, subrectangular, distinctly longer than broad, lateral and posterior margins weakly convex. Mandibles subtriangular; masticatory margin with five teeth, including largest apical tooth, followed by medium-sized preapical tooth, a small tooth, medium-sized prebasal tooth, and small basal tooth; basal margin without denticles. Clypeus broad and convex medially, shorter than broad, its anterior margin broadly convex, posterior clypeal margin straight medially. Eyes moderately large, oval, convex, with 14–15 ommatidia along the longest axis, located at mid-length of head laterally; outer margin of eyes reaching lateral margin of head. Ocelli present, lateral ocelli as large as median ocellus; distance between lateral ocelli clearly longer than distance between median ocellus and lateral ocellus. Antennal scapes slender, clavate, extending beyond posterolateral corners of head by about one-third of its length. Antennal segment II longer than broad and longer than segments III and IV; segments V –X each clearly longer than broad. Frontal lobe narrow and frontal carina reach to level of mid-length of eyes.

Mesosoma: in profile pronotum with weakly convex dorsal outline; mesonotum slightly sloping gradually to metanotal groove; in dorsal view, pronotum slightly broader than long and clearly broader than mesonotum but almost as broad as propodeum; metathoracic spiracle in profile raised but lower than the level of propodeal spines; promesonotal suture and metanotal groove distinct; mesopleuron clearly demarcated from metapleuron by deep groove; metapleuron not demarcated from lateral face of propodeum. Propodeum in profile with weakly convex dorsal outline; in profile, propodeal spines short, subtriangular, rather sharp apically, almost as long as broad at base; in dorsal view, tip of propodeal spine pointed backward and outward.

Petiole sessile; in profile petiolar node subtriangular, longer than high, its anterior margin weakly convex, posterior margin straight; dorsum of petiole with a pair of sharp spines, that are pointed above; in dorsal view petiolar node subrectangular, narrower posteriorly; subpetiolar process weakly developed.

Dorsum of head punctate but slightly shiny; area in front of eye laterally (lower gena) with longitudinal striation; ventral surface of head punctate, but punctation weaker than on the dorsum; pronotum entirely punctate; mesopleuron with longitudinal striation except for lower portion punctate; propodeum punctate; petiole and gaster smooth and shiny. Antennal scape punctate; coxae smooth and shiny; femora and tibiae punctate.

Dorsum of head with sparse standing hairs mixed with short appressed hairs; pronotum with sparse standing hairs; mesonotum with 5–6 standing hairs; propodeal dorsum with sparse standing hairs ≤ 10; gaster with dense standing hairs. Head, mesosoma, petiole, gastral segment I, and anterior half of gastral segment II yellow; remaining parts of gaster dark to dark brown; antennal scape and legs yellow; flagellar segments of antennae largely dark brown.

REMARKS. Lepisiota bicolor sp. n. is most similar to L. pulchella (Forel, 1892) from India in having dense punctures on head and mesosoma and yellow gastral segment I yellow (compared with L. pulchella syntype images, CASENT0909894) . However, L. bicolor can be easily separated from L. pulchella by 1) head longer than broad (almost as long as broad in L. pulchella ); 2) flagellar segment of antennae largely dark brown (entirely grey in L. pulchella ); 3) in full-face view, outer margin of eyes reaching lateral margin of head (not touch in L. pulchella ); 4) petiole smooth and shiny (punctate in L. pulchella ); 5) legs yellow (grey alternating with dark brown in L. pulchella ); 6) head and mesosoma distinctly yellow (yellowish brown in L. pulchella ); 7) gastral segment I entirely yellow (partly yellow in L. pulchella ); 8) anterior half of gastral segment II yellow (entire segment dark to dark brown). Lepisiota bicolor is also similar to L. thepthepae in having dense punctures on head and mesosoma. However, L. bicolor can be separated from L. thepthepae by 1) head, mesosoma, petiole, and gestral segment I yellow (head and gaster dark brown; mesosoma and petiole reddish brown in L. thepthepae ); 2) ventral surface of head punctate (smooth and shiny in L. thepthepae ); 3) posterior clypeal margin almost straight medially (feebly concave medially in L. thepthepae ); 4) mesonotal spiracle in profile lower than level of propodeal spines (higher than level of propodeal spines in L. thepthepae); gaster bicolor (dark brown in L. thepthepae ).

HABITAT. The type series was collected from soil in a paddy field at an elevation about 900 m above sea level. A colony from Tak Province, western Thailand (TH15-WJT-46) was collected in a dry dipterocarp forest, ca. 1,200 m above sea level. Thus, this species should be restricted to highland. Lepisiota bicolor is sympatric with L. siamensis in Chiang Rai Province, northern Thailand.

ETYMOLOGY. The specific name is a Latin, “ bicolor ” meaning having two colors.

DISTRIBUTION. Thailand: Chiang Rai and Tak Provinces ( Fig. 6 ).

Figures

Fig 1. Lepisiota bicolor Jarernkong et Jaitrong, sp. n., holotype worker (THNHM-I- 24825, THNHM). A – body in profile view; B – head in full-face view; C – body in dorsal view.

Fig 6. Distributions of the new species of Lepisiota in Thailand.