Erromyrma latinodis (Mayr, 1872)

Ramamonjisoa, Manoa M., Rasoamanana, Nicole & Fisher, Brian L., 2023, Description of the male of Erromyrma Bolton & Fisher, 2016 (Hymenoptera, Formicidae), ZooKeys 1163, pp. 61-77 : 61

Erromyrma latinodis (Mayr, 1872)

Monomorium latinode Mayr, 1872: 152 (w.). Lectotype worker (designated by Heterick 2006: 108): Malaysia ( “Borneo”), Sarawak, 1865-66 (J. Doria & O. Beccari), unique specimen identifier: CASENT0010941, examined [BMNH]. Paralectotype with same data as lectotype, unique specimen identifier: CASENT0905756, examined [MSNG]. [Combination in Erromyrma : Fisher and Bolton 2016: 276].

Monomorium latinode var. bruneum Emery, 1893: 243 (w.). Lectotype worker (designated by Heterick 2006: 108): Sri Lanka ( “Ceylon”), Kandy, i.-ii.1892 (E. Simon), unique specimen identifier: CASENT0008632, examined [MSNG]. [Junior synonym of Monomorium latinode : Heterick 2006: 108].

Monomorium latinode var. voeltzkowi Forel, 1907: 78 (w.). Lectotype worker (designated by Heterick 2006: 108): Tanzania ( “Ostafrika”), Pemba I., Chake-Chake (A. Voeltzkow) [MCZC]. Paralectotype with same data as lectotype, unique specimen identifier: CASENT0101928, examined [MHNG]. [Junior synonym of Monomorium latinodis : Bolton 1987: 429].

Monomorium latinodoides Wheeler, 1928: 17 (w.). Syntype worker: China: Hong Kong, Kowloon (F. Silvestri) unique specimen identifier: MCZ-ENT00727982, examined [MCZC]. comb nov., syn. n.

Note.

The type series at MCZ was examined. The syntypes series are labeled “Kowloon” (F. Silvestri): one pin with 3 workers (MCZ-ENT00020883) and 2 workers and one dealate queen on a second pin (MCZ-ENT00727982). The workers match the description and diagnosis (see below) of worker of E. latinodis . We formally combine the species in Erromyrma and synonymize the species with E. latinodis . However, we exclude the queen (on MCZ-ENT00727982) from the syntype series; it belongs to the genus Carebara (Westwood, 1840).

Diagnosis.

Erromyrma workers [modified from Heterick (2006) and Fisher and Bolton (2016)]:

Worker caste polymorphic

Palp formula 3,3

Mandible triangular, smooth, and shiny

Five mandibular teeth

Antenna with 12 segments, with 3-segmented apical club

Scape short, failing to reach occipital margin

Compound eyes present and conspicuous

Clypeus with a distinct unpaired seta at the midpoint of the anterior margin

Frontal carinae short and parallel

Antennal scrobe absent

Head without raised nuchal (= occipital) carina

Tibial spurs absent from meso- and metatibia

Promesonotal suture not distinct in dorsal view

Metanotal groove present

Propodeum unarmed

Propodeal dorsum with strong transverse striolae

Petiole pedunculated

Subpetiolar process absent

Sting developed

Erromyrma latinodis males:

The following combination of characters diagnose males of Erromyrma latinodis .

Palp formula 5,3

Mandible triangular with distinct basal and masticatory margins (Fig. 2B )

Four mandibular teeth (Fig. 2B )

Antenna short and filiform, with 13 segments; pedicel subglobular (Fig. 2B )

Scape short (SI <33, Fig. 2B )

Compound eyes large (EL/HW1 0.58, Fig. 1A )

Ocelli present and similar in size (Fig. 1A )

Clypeus with anterior margin convex. (Fig. 2B )

Frontal carinae absent (Fig. 2B )

Antennal scrobe absent (Fig. 2B )

Head without raised nuchal (= occipital) carina (Fig. 2C )

Notauli absent (Fig. 2C )

Single spur present on meso- and metatibia (Fig. 2A )

Pterostigma present on the forewing (Fig. 3 )

First median-cubital cross-vein (1m-cu) present on the forewing (Fig. 3 )

Cubital vein of the forewing fused with the median vein (M+Cu) and forms an angle higher than 45° with M (Fig. 3 )

Forewing cross-vein 2rs-m absent (Fig. 3 )

Petiole pedunculate (Fig. 2A )

Postpetiole elongated anteriorly, subglobose in lateral view (Fig. 2A )

Abdominal segment IV elongate and not shouldered (Fig. 2A )

Pygostyles present (Fig. 2A )

Male measurements (N = 2). HL 0.60-0.62, HW1 0.48-0.5, HW2 0.62-0.65, EL 0.28-0.29, EW 0.21-0.23, IOD 0.20-0.21, LOD 0.06-0.07, OOD 0.16-0.18, SL 0.12-0.14, F1 0.09-0.10, PL 0.51-0.54, PW 0.20-0.21, PPW 0.33-0.34, CI 81-82, SI 28, EI 0.58.

Description.

Erromyrma latinodis males:

Structure. In full-face view, the head including compound eyes slightly wider than long. Posterior head margin relatively rounded; head with three large, rounded ocelli of the same size, situated on the frontal face of the head, lateral ocelli directed 45° toward lateral sides. Compound eye large, strongly bulging. Anterior margin of clypeus convex. Mandible well developed and elongate triangular; masticatory margin with four teeth, the basal and masticatory margins are distinct.

Antennae 13-segmented short and filiform, pedicel subglobular. The mesoscutum is strongly convex and bulging, in the dorsal view much broader than the head at the level of the forewing insertion. In dorsal view, pronotum short in the median portion; notauli absent on the mesoscutum; mesoscutellum broader than long and smaller than mesoscutum. Metapleural gland bulla present with metapleural lobe closed. In profile, propodeal angle rounded, without spines or teeth. Hind femora longer than tibia.

In lateral view, petiole distinctly pedunculated; subpetiolar process absent (Fig. 2A ). In dorsal view, abdominal segment III (postpetiole) elongated anteriorly; abdominal segment IV not shoulder and broader than the remaining tergites.

Sculpture. Clypeus, dorsum, lateral face, and venter of head weakly smooth and shiny. Pro- and mesothorax extensively smooth or very superficially sculptured and shiny, with posterolateral area of mesoscutum and posterior zone of mesopleuron unsculptured with shiny area. Metanotum and metapleuron unsculptured and matte. Apical area of anterior slope of petiole, coxae, femora, and tibiae of all legs smooth to superficially sculptured and shiny; tarsi entirely microsculptured. Gaster (abdominal segments IV to the apex) entirely smooth to superficially sculptured and shiny.

Color. Body and mandible largely brownish yellow except the ocellar region and the abdominal segments IV to the apex, brown.

Pilosity. Anterior margin of clypeus with a pair of stout setae and without a distinct unpaired seta at its midpoint. Mandible covered with standing hairs. Antennal scape and pedicel with short and decumbent whitish hairs; the flagellomeres densely hairy. Hairs on head and body moderately abundant, erect, short, and stout. Pronotum, mesoscutum, and mesoscutellum with many obliquely standing hairs; hairs on mesopleuron much sparser; metanotum and propodeum with erect hair. Femora and tibiae with appressed hairs; tarsi covered with short appressed hairs. Posterior margins of each abdominal tergite and sternite with long and suberect hairs. Parameres covered with stout hair.

Wings. (Fig. 3 ) Forewing with four closed cells. Costal vein (C) absent. Pterostigma pigmented, visible on the leading edge of the forewing. Radial vein (R) fused proximally to constitute Sc+R+Rs before reaching the pterostigma.

Radial sector (Rs). Past the separation from Sc+R+Rs, Rs usually short free abscissa down curved and never reaching to the costal margin, the radial sector connects to the pterostigma via the second radial-radial sector cross-vein (2r-rs). Then merging with median vein (M) and continuing fused (Rs+M).

Median vein (M). Further away from the leading wing margin is the median vein, proximally fused with cubital vein (M+Cu), following separation continuing as a free abscissa M before joining with radial sector to form Rs+M. Median vein (M) is fused with radial sector and present in past the junction of the radial sector.

Cubital vein (Cu). Proximally the cubital vein is fused with median vein (M+Cu), the cubital vein (Cu) divided by median-cubital cross-vein (1m-cu) the cubital vein does not connect to the distal wing margin.

Anal vein (A). A longitudinal vein running near the posterior wing margin. Consists of a free abscissa fused to cubital-anal cross-vein (cu-a), and continuing past cu-a.

Comments.

The tribe Solenopsidini is separated from other Malagasy myrmicine tribes by the following combination of characters: with the head in full-face view, mandibles with masticatory margin less than five teeth; antennal scrobe reduced to absent; pedicel not more elongated than the remaining segments; ocelli present and same size situated on the frontal face of the head, lateral ocelli directed toward oblique front sides; occipital carina not visible in full-face view; head (including compound eyes) slightly wider than long with occipital margin of head rounded. In lateral view, the anterodorsal margin of mesopleuron lower than the highest point of the wing process, pronotum and mesonotum from a smooth convexity, pronotal furrow less marked; forewing venation: cross-vein 2rs-m absent, costal vein absent, radial sector down curved and never reaching to the costal margin; propodeal spines absent; pygostyle present; abdominal segment III attached anteriorly to abdominal segment IV; peduncle of abdominal segment III is distinctly longer than that of the petiole; single tibial spur present on the front leg. In dorsal view, notauli absent.

Erromyrma can be distinguished from three other genera, Adelomyrmex (Emery, 1897), Monomorium (Mayr, 1855) and Syllophopsis (Santschi, 1915), by its subglobular pedicels. It can be separated from the genus Solenopsis (Westwood, 1840) by the number of its antennal segment.

Figures

Figure 1. Illustration of measurements of Erromyrma latinodis (CASENT 0788835) A head in full-face view B segment abdominal in dorsal view C segment abdominal in lateral view.

Figure 2. Erromyrma latinodis (CASENT 0788835) A body in lateral view B head in full-face view C body in dorsal view.

Figure 3. Male forewing veins of Erromyrma latinodis (CASENT 0788835). Abbreviations: Pt pterostigma; Sc subcosta; R, r radius; Rs, rs radial sector; M, m media; Cu cubitus; A, a, anal.