Lepisiota chutimae Jaitrong, Waengsothorn et Buddhakala, 2022

Jaitrong, W., Waengsothorn, S. & Buddhakala, N., 2022, A new species of the ant genus Lepisiota Santschi, 1926 (Hymenoptera: Formicidae) from Thailand, Far Eastern Entomologist 456, pp. 1-8 : 3-8

Lepisiota chutimae Jaitrong, Waengsothorn et Buddhakala , sp. n.

http://zoobank.org/NomenclaturalActs/ 7D688A72-114F-485D-AB72-DEDA7483679B

Figs 1–3

TYPE MATERIAL. Holotype – worker (THNHM-I-24840, THNHM), NE

Thailand: Nakhon Ratchasima Province, Wang Nam Khiao District, Sakaerat

Environmental Research Station, DEF (dry evergreen forest) 22.III 2021, W.

Jaitrong leg., TH21-WJT-002. Paratypes: 50 workers (THNHM-I-24841 to

THNHM-I-24889, THNHM) and a queen (THNHM-I-24890, THNHM), same data as holotype.

NON-TYPE MATERIAL EXAMINED. Two workers (THNHM-I-24891,

THNHM), NE Thailand: Nakhon Ratchasima Province, Wang Nam Khiao

District, Huai Nam Khem, plantation, 22. VI 2018, W. Jaitrong leg.; 2 worker

(THNHM-I-24892, THNHM), E Thailand: Chachoengsao Province, Tha Takiap

District, 28.XII 2002, W. Jaitrong leg.; 6 workers (THNHM-I-24893, THNHM) ,

same locality and collector, 22.VIII 2003, WJT03-TH-252.

DESCRIPTION. Worker ( Fig. 1 ).

Measurements and indices. Holotype: HL 0.56, HW 0.46, EL 0.17, SL 0.66, ML

0.76, FeL 0.63, PL 0.30, PH 0.33, CI 82, SI 143, EI 36, FeI 71.

Paratypes (n = 10): HL 0.53–0.56, HW 0.46, EL 0.13–0.17, SL 0.63–0.66, ML

0.76, PL 0.30, PH 0.33–0.35, FeL 0.63–0.66, CI 82–88, SI 136–143, EI 29–36, FeI

71–75.

Head: In full-face view, slightly longer than broad, lateral and posterior margins convex. Mandible subtriangular; masticatory margin with five teeth, including largest apical tooth followed by 2 small teeth, medium-sized prebasal tooth, and small basal tooth; basal margin without denticles. Clypeus broad and convex medially, subrectangular, shorter than broad, its anterior margin roundly convex. Eye relatively large,

convex, with 17–18 ommatidia along the longest axis, located at mid-length of head laterally; lateral margin of eye reaching lateral margin of head. Ocelli present; lateral ocelli relatively larger than median ocellus; distance between lateral ocelli equal to distance between median ocellus to lateral ocellus. Antennal scape slender, clavate,

1/3 of its length, extending beyond posterior margin of head; antennal segment II longer than broad and longer than each of segments III and IV; segments V –X each thin and longer than broad; apical segment ( XI) forming a club. Frontal lobe narrow and frontal carina short barely attaining level of anterior margin of eye.

profile view; B – head in full-face view; C – body in dorsal view.

Mesosoma: Stout, in profile pronotum with almost straight dorsal outline, while mesonotum sloping gradually to metanotal groove; mesothorax reduced and slender,

mesonotal spiracles raised slightly higher than mesonotal dorsal outline; promesonotal suture and metanotal groove distinct; mesopleuron clearly demarcated from metapleuron by deep groove; metapleuron not demarcated from lateral face of propodeum;

in dorsal view pronotum clearly broader than mesonotum but slightly broader than propodeum; propodeum about 2/3 length of mesonotum in dorsal view. Propodeum in dorsal view with almost straight dorsal outline, sloping gradually to tip of propodeal spine; propodeal spine large pointed up- and backward; declivity of propodeum more or less flat.

Petiole in profile subtriangular and sessile, elevated anteriorly, longer than high,

its anterior face vertical, dorsal and posterior faces long and weakly concave; dorsum of petiole with a pair of sharp spines; in dorsal view petiolar node subrectangular,

slightly broader than long (DPI 100–105), narrower posteriorly; subpetiolar process almost absent. Gaster elongate, in dorsal view, first gastral segment slightly narrower than II. Acidopore present.

Entire body (head, mandible, antennal scape, mesosoma, legs, petiole, and gaster) smooth and shiny, except mesopleuron wrinkled. Pilosity comparatively sparse; dorsa of head, mesosoma, and metasoma with sparse standing hairs mixed with sparse shorter hairs; tip of metasoma with dense standing hairs; tibiae with dense decumbent hairs. Head, mesosoma, and petiole yellowish brown; gaster dark brown.

Queen ( Fig. 2 )

Measurements and indices. Paratype: HL 0.73, HW 0.83, EL 0.30, SL 0.76, ML

1.49, PL 0.36, PH 0.33, FeL 0.89, CI 114, SI 92, EI 36, FeI 108.

Head: In full-face view, slightly shorter than broad, lateral margins convex and posterior margin (between lateral ocelli) roundly concave. Mandible and clypeus with the same condition as in worker. Eye relatively large, convex, with over 25

ommatidia along the longest axis, located at mid-length of head laterally; outer margin of eye breaking lateral margin of head. Ocelli present, large; distance between lateral ocelli longer than that between lateral ocellus to median ocellus.

Antennal scapes slender, clavate, 1/3 of its length extending beyond posterior margin of head; antennal segment II longer than broad and as long as segments III and IV combined; segments V –X each thin and longer than broad; apical segment

( XI) forming a club. Mandible, clypeus, frontal lobe, and frontal carina the same condition as in worker.

Mesosoma enlarged and high; pronotum in profile distinctly lower than mesoscutum, in dorsal view narrow and subrectangular; promesonotal suture distinct;

anterior half of mesoscutum in profile convex but straight in posterior half; mesonotum in dorsal view large, almost 3 times as long as mesoscutellum; mesoscutellum clearly shorter than broad and demarcated from mesoscutum by deep groove; mesopleuron broad, anepisternum clearly demarcated from katepisternum by oblique mesopleural suture; metanotum very narrow. Propodeum low with convex dorsal outline; declivity of propodeum more or less flat.

Petiole in profile sessile, longer than high, elevated anteriorly and covered with gastral tergite I. Gaster enlarged and elongate, in dorsal view, gastral segment I broader and longer than segments II– V.

Entire body (head, mandible, antennal scape, mesosoma, legs, petiole, and gaster)

smooth. Body covered with dense short pubescence with sparse setae; setae on gastral segments I–IV located along posterior edges. Antennae and legs without setae. Head, mesosoma and petiole reddish brown; gaster dark brown.

DIAGNOSIS. Lepisiota chutimae sp. n. is most similar to L. emmelii ( Kutter,

1932) from Indonesia (Java) and L. chapmani ( Wheeler, 1935) from the Philippines

(Negros Oriental) in having a slightly smooth, shiny, and yellowish body. However,

view; B – head in full-face view; C – body in dorsal view.

L. chutimae sp. n. can be separated from L. chapmani by gaster dark brown

(yellowish brown in L. chapmani ); mesopleuron weakly sculptured (sharply longitudinally rugulose in L. chapmani ); posterior peduncle of petiole smooth and shiny (finely punctate in L. chapmani ); head and pronotum clearly smooth and shiny (very finely and superficially reticulate or shagreened with smooth and shining interspaces in L. chapmani ). Lepisiota chutimae sp. n. can be distinguished from L. emmelii by tip of petiolar spine directed sideward (upward in L. emmelii ,

see figure on page 209 in Kutter, 1932 for comparison); gaster dark brown

(yellowish brown in L. emmelii ); anterior face of petiolar node feebly concave

(weakly convex in L. emmelii ); found in lowland (highland in L. emmelii ).

HABITAT. The new species is arboreal welling on shrub trees in lowlands of dry evergreen forests. The type series nested under a leaf of Memecylon ovatum

Sm. at about 3 meters above the forest floor (arrow on Fig. 3A ). The nest was covered with a dead leaf and no silk was seen. A spider was found in the nest of the type series.

covered with a dead leaf; C – nest structure.

DISTRIBUTION. Thailand (Nakhon Ratchasima and Chachoengsao Provin-

ces).

ETYMOLOGY. The specific name is dedicated to Professor Dr. Chutima Eam-

chotchawalit, the governor of Thailand Institute of the Scientific and Technological

Research ( TISTR), who is in charge of the Sakaerat Environmental Research Station,

the type locality of the species and strongly supported conducting biodiversity research including our research project.

We would like to express our heartfelt gratitude to Prof. Seiki Yamane (Kago-

shima University Museum, Japan) for his valuable comments on and corrections to an earlier version of the draft. This study was partly supported by the Office of

Thailand Science Research and Innovation.

Figures

Fig 1. Lepisiota chutimae sp. n., holotype worker (THNHM-I-24840). A – body in

Fig 2. Lepisiota chutimae sp. n., paratype queen (THNHM-I-24890). A – body in profile

Fig 3. Nesting site and nest structure of Lepisiota chutimae sp. n. A – nesting habitat on Memecylon ovatum Sm., a shrub tree (arrow points to nesting site); B – nest under a leaf and