Myrmecina salmahae Satria et Eguchi, 2022

Satria, R. & Eguchi, K., 2022, A new species of the genus Myrmecina Curtis, 1829 (Formicidae: Myrmicinae) from Sumatra, Far Eastern Entomologist 463, pp. 1-7 : 3-6

Myrmecina salmahae Satria et Eguchi , sp. n.

https://zoobank.org/NomenclaturalActs/ 46504DB7-3EA8-4780-9598-AE20B48F217E

Figs 1 , 2

TYPE MATERIAL. Holotype: worker (individual code: SEMUT 22iv2022 B),

Indonesia: West Sumatra, 50 Kota District, Situjuah Limo Nagari, Situjuah

Gadang, Sago Moutain, 3°49'521" N, 97°31'198" E, ca. 2000 m alt., 13.I 2022, Nur

Aqsha leg. (MZB). Paratypes: workers (n=6, individual code: SEMUT 13i2022,

SEMUT 22iv2022 A, SEMUT 22iv2022 C, SEMUT 22iv2022 D, SEMUT 22iv2022 E,

SEMUT 22iv2022 F), same data as holotype (RSC) .

WORKER MEASUREMENTS AND INDICES. Holotype (n=1): HL 1.73 mm,

HW 1.94 mm, MDL 0.90 mm, EL 0.27 mm, SL 1.54 mm, WL 2.25 mm, PNW 1.35

mm, PSL 0.36 mm, PTH 0.54 mm, PTL 0.56 mm, CI 111, MDI 51, SI 79, PTHI 96.

Paratypes (n=6): HL 1.73−1.81 mm, HW 1.94−2.02 mm, MDL 0.89−0.97 mm,

EL 0.27−0.28 mm, SL 1.54−1.62 mm, WL 2.18−2.36 mm, PNW 1.35−1.38 mm,

PSL 0.34−0.36 mm, PTH 0.53−0.56 mm, PTL 0.56−0.58 mm, CI 111−115, MDI

WORKER DIAGNOSIS. Myrmecina salmahae sp. n. is easily separated from the other 16 Myrmecina species recorded from Sumatra by a combination of the following characters of the worker: relatively large species (HL 1.73−1.81 mm, HW

1.94−2.02 mm, WL 2.18−2.36 mm); posterior margin oh head slightly concave;

mesosoma in lateral view short and stout, as long as height, with dorsal outline convex; eumetanotal spine present and small; propodeal spines in lateral view elongate-triangular, as long as broad and pointed apically; propodeal declivity with posterodorsal angle less than 90°; subpetiolar process absent; head dorsally with coarse longitudinal rugae; mesosoma, petiole and postpetiole with coarse irregular longitudinal rugae.

code: SEMUT 14iv2022 B).

WORKER DESCRIPTION. Relatively large (HL 1.73−1.81 mm, HW 1.94−2.02

mm, WL 2.18−2.36 mm). Head in full-face view subrectangular, slightly shorter than wide, with posterior margin slightly concave ( Fig. 2A ); lateral sides of head shallowly convex; occipital corners rounded, not projected posteriorly. Clypeus consisting of flat dorsal disc and steep anterior face, laterally serrate; its anterior margin almost straight, with a small median tooth and a pair of lateral denticles.

Labrum with pair of apical processes. Compound eye relatively small (EL 2.18−2.36

mm), with 34−45 ommatidia. Mandible triangular; masticatory margin with large apical tooth, followed by small preapical tooth, large third tooth, 5 blunt denticles,

and a blunt basal tooth. Antenna 12-segmented, with 3-segmented club; apical seg-

ment slightly longer than 10th and 11th segments combined; scape relatively long,

distinctly surpassing posterolateral corner of head when laid backward. Mesosoma in lateral view short and stout, as long as height, with dorsal outline convex;

anterior ventrolateral portion of pronotum forming distinct process; mesonotum completely fused with pronotum; lower portion of mesopleuron broadly concave anteriorly; mesopleuron not differentiated from metapleuron; eumetanotal spine present but small; propodeal spines in lateral view elongate-triangular, as long as broad and pointed apically; propodeal declivity slightly concave, with lateral carinae not developed, with posterodorsal angle less than 90°; posteriormost portion of propodeum with very high lateral walls (propodeal lobes) ( Fig. 2B ). Petiole in dorsal view as broad as long, rectangular, in lateral view with anterior slope almost straight, dorsal outline almost straight to weakly concave, and ventral outline straight without any denticle. Postpetiole in dorsal view much broader than long,

broader than petiole; sternopostpetiolar process absent. Gaster in dorsal view slightly elongate circular; anterior margin of first gastral tergite slightly concave,

with anterolateral corner very weakly angled.

mesosoma in lateral view; C – mesosoma in dorsal view; D – antenna; E – petiole and postpetiole in dorsal view; F – petiole and postpetiole in lateral view.

Head dorsally with coarse longitudinal rugae; those on lateral part of head diver-

ging posteriad; flat dorsal disc of clypeus smoth and shiny, with irregular punctures around anterolateral corner; ventrolateral area (temple + gena) of head smooth and shiny. Mesosoma, petiole and postpetiole with coarse irregular longitudinal rugae;

declivity and posteriormost part of propodeun smooth and shiny. Gaster smooth and shiny.

Body covered with abundant long erect setae; clypeus with several long setae,

and a pair of long setae arising from the median tooth of its anterior margin; scape with many suberect to erect hairs that are longer than scape width; all legs with numerous suberect to erect hairs.

For color pattern see Figs 1 , 2 ; body black, with appendages dark reddish brown.

DISTRIBUTION. So far known only from the highland of Sumatra.

TAXONOMIC REMARKS. Myrmecina salmahae sp. n. can not be assigned to any species group which is proposed by Okido et al. (2020). New species is keyed out as M. aspera at the couplet 19 of the key provided by Okido et al. (2020), but is distinguished from the latter by a combination of the following characters:

masticatory margin of mandible bent at midlength (vs. straight in the latter); eye large with EL 0.27−0.28 mm and 34−45 ommatidia (vs. small with EL 0.14 mm and

7 ommatidia in the latter); mesosoma in lateral view short and stout, as long as height (vs. longer than height in the latter); mesosoma with coarse irregular longitudinal rugae (vs. coarse longitudinal rugae in the latter). It is also morphologically similar to M. boltoni , and M. padangensis , on the basis of the following characteristics: head and mesosoma with coarse longitudinal rugae;

antennal scape relatively short; eumetanotal spine present; propodeal spine relatively short; petiole longer than postpetiole in lateral view; petiole without subpetiolar process. However, it is distinguishable from the latter two by the following characteristics: posterior margin oh head slightly concave (vs. slightly concave in M. boltoni ; almost straight in M. padangensis ); mesosoma in lateral view short and stout, as long as height (vs. longer than height in the latter two); eye large with EL 0.27−0.28 mm and 34−45 ommatidia (vs. 0.11−0.16 mm and 5−10

ommatidia in M. boltoni ; 0.14 mm and 8 ommatidia in M. padangensis ); propodeal spine relatively small, as long as broad at base and pointing posteriad (vs. longer than broad in the latter two); mesosoma in dorsal view with coarse and irregular rugae (vs. longitudinal rugae in M. boltoni ; irregular rugae in M. padangensis );

forecoxa smooth and shiny (vs. sculptured in M. boltoni ; smooth and shiny in M.

padangensis).

BIONOMICS. New species was collected from leaf litter in the primary highland forests. Other information about the biology of this species is absent.

ETYMOLOGY. The species is named in honor of Dr. Siti Salmah, the emeritus professor of Andalas University, an authority on entomology and taxonomy in

Indonesia.

Figures

Fig. 1. Myrmecina salmahae sp. n., body in lateral view (holotype, worker, individual

Fig. 2. Myrmecina salmahae sp. n. (holotype, worker): A – head in full-face view; B –