Sericomyrmex bondari

Workers mostly forage alone but will sometimes form short, dense foraging columns in the immediate area of the nest entrance.

Identification
Jesovnik and Schultz (2017) - Large species; hairs thick and dark; posterior cephalic emargination deep, gradually impressed; posterior cephalic corner acute to rounded; mandible dorsally smooth, glossy; frontal lobe triangular, narrow; mesosomal tubercles distinct, sometimes relatively sharp; first gastral tergite with lateral carinae weakly to moderately developed, dorsal carinae absent.

It is difficult to mistake S. bondari for any other Sericomyrmex species because of its thick, dark hairs. When individuals with reduced hairs are encountered, the sympatric sister species, Sericomyrmex mayri, can be separated from bondari by its striate mandibles, wider head (CI mayri=108, CI bondari=104), narrower frontal lobes, and shallow posterior cephalic emargination. The morphologically similar Sericomyrmex radioheadi is smaller (medium-sized, while bondari is large); completely lacks dark hairs; and has a longer antennal scape (SI=77), reduced lateral pronotal tubercles, and unusually sharp, long lateral mesonotal tubercles. The thick, dark hairs and large size are also useful for separating S. bondari queens from those of mayri, as are the lateral pronotal tubercles, which are more pronounced in bondari than in queens of other Sericomyrmex species.

The specimens of S. bondari with slightly to very reduced hairs include five workers from Brazil (Melgaço, Pará), one from Ecuador (Cuyabeno), and three from Venezuela (Bolívar) out of a total of ~200 dry-mounted specimens we examined. Aside from reduced hairs they have the typical bondari morphology and measurements. Individuals with an intermediate state (hairs slightly reduced) exist in Brazil, some from Melgaço (Pará) and some from Espírito Santo. The existence of intermediate forms, the molecular phylogeny, and PCA analysis of the morphological measurement data all indicate that populations with reduced hairs are rare variants of bondari rather than separate species. Another variation within bondari, occurring in the Brazil (Carajás, Pará) specimens, is a slightly bicolored (rather than uniformly colored) integument, but this state occurs only in a minority of workers from the same nest, the rest of which are homogeneously colored.

Distribution
Brazil, Bolivia, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname.

Distribution based on Regional Taxon Lists
Neotropical Region: Bolivia, Brazil.

Biology
Castano-Meneses et al (2017) - The springtail species Cyphoderus agnotus Börner (Cyphoderidae: Cyphoderus) is known from nests of this ant.

Nomenclature

 *  bondari. Sericomyrmex bondari Borgmeier, 1937b: 248, figs. 37, 38 (w.) BRAZIL.
 * Ješovnik & Schultz, 2017a: 45 (q.l.).
 * Status as species: Kempf, 1972a: 229; Bolton, 1995b: 382; Ješovnik & Schultz, 2017a: 44 (redescription).
 * Senior synonym of beniensis: Ješovnik & Schultz, 2017a: 44.
 * beniensis. Sericomyrmex beniensis Weber, 1938b: 182 (w.) BOLIVIA.
 * Status as species: Kempf, 1972a: 229; Bolton, 1995b: 382.
 * Junior synonym of bondari: Ješovnik & Schultz, 2017a: 44.

Jesovnik and Schultz 2017:

Worker
(lectotype): HWe 0.96–1.40 (1.16) HW 0.98–1.40 (1.18) HW1 0.93–1.40 (1.2) HW2 1–1.56 (1.24) HW3 0.65–0.9 IFW1 0.65–1.00 (0.76) IFW2 0.22–0.38 (0.3) HL1 0.99–1.30 (1.01) HL2 0.87–1.12 (0.93) SL 0.68–0.96 (0.78) EL 0.14–0.20 (0.16) Om 8–12 (11) WL 1.25–1.76 (1.52) PL 0.24–0.4 (0.38) PPL 0.18–0.3 (0.19) GL 0.81–1.24 (0.96) HFL 1.12–1.52 (1.3) PW 0.66–1.02 (0.78) (0.8) CI 93–110 (107) FLI 61–72 (66) SI 63–78 (67) OI 12–17 (14) CEI 6–17 (13) [N=59]

Pilosity. Hairs thick, black, often curved, appressed to erect, mostly suberect, longer and denser on dorsal than on lateral surfaces, e.g., mesosoma laterally with barely any hairs, just pubescence.

Head. In full-face view slightly broader than long (CI=104 ± 3), posterior corner rounded to acute, posterior cephalic emargination distinct and deep (CEI=13 ± 2), gradually impressed. Vertexal impression often distinct and deep, sometimes extending anterad to include frons, frontal tumuli usually faint. Mandible with 7–9 teeth, dorsally smooth, glossy, finely transversely striate along masticatory margin, striation sometimes faint. Eyes medium-sized (OI =15 ± 1), mildly convex, lacking white layer, 8–12 ommatidia across largest diameter. Frontal lobe triangular, narrow (FLI=67 ± 2), posterior margin shorter than medial, and with long lateral margin, giving lobe appearance of being directed anterad. Frontal carina complete, reaching posterior cephalic corner, antennal scape relatively short (SI=71 ± 3), not reaching posterior cephalic corner. Antennal scape with thick black hairs, antennal flagellum lacking thick black hairs, but with pubescence and thin, long, light yellow hairs.

Mesosoma. Lateral pronotal and lateral mesonotal tubercles from moderately developed to large and sharp, variable within species and within colonies. Propodeal carinae low, serrate, each with posterodorsal denticle.

Metasoma. Petiole with two low denticles dorsally, postpetiole with two dorsal and two lateral carinae, lateral pair sometimes faint. First gastral tergite with lateral carinae distinct, dorsal carinae faint or absent. Decumbent to suberect hairs on gastral dorsum curved at base and sometimes hooked at tip, margins of gastral segments 2–5 (A5-A8) with curved suberect to erect hairs.

Queen
HWe 1.33–1.48 HW 1.35–1.48 HW1 1.40–1.46 HW2 1.15–1.58 HW3 0.93–1.09 IFW1 0.99–1.02 IFW2 0.34–0.40 HL1 1.32–1.44 HL2 1.12–1.24 SL 0.92–1.00 EL 0.27–0.29 Om 17–21 EW 0.08–0.08 WL 1.96–2.25 PL 0.40–0.45 PPL 0.24–0.28 GL 1.95–2.05 HFL 1.60–1.64 PW 1.15–1.28 FWg 6.71–6.71 HWg 4.66–4.66 CI 98–103 FLI 69–75 SI 68–71 OI 19–22 [N=3]

Head. Mandible with 7–8 teeth, dorsally smooth, glossy, finely transversely striate only along masticatory margin. Preocular carina fading posterior to eye, several short and thin supraocular carinae present, never reaching posterior cephalic corner. Eye large (OI=20 ± 1) and convex, 17–21 ommatidia across largest diameter. Frontal lobe wider than in worker (FLI=73 ± 3), antennal scape as in worker, not reaching posterior cephalic corner.

Mesosoma. Lateral pronotal tubercles distinct. Scutum in dorsal view with notauli faint, sometimes absent. Median mesoscutal line sometimes anteriorly developed into weak costa, posteriorly with shallow longitudinal impressions on each side. Parapsidal lines thin, slightly curved. Scutellum inflated, short in dorsal view, narrowing posteriorly, posterior margin with V-shaped, relatively deep, medial notch; notch sometimes continuing into median impression that divides scutellum in two lateral parts. Propodeal carinae short, low, each with posterodorsal denticle, sometimes carinae reduced and only denticles visible.

Metasoma. Petiole in frontodorsal view with two narrow, long dorsal denticles and two smaller, lateral denticles. Postpetiole with two short and low dorsal carinae and two low lateral denticles. First gastral tergite with lateral carinae strongly developed, dorsal carinae absent or faint, anteromedian groove distinct.

Larva
Two to four setae on dorsal and lateral body surfaces on each side. Supra-antennal setae present. Four genal setae on each side. Mandibular apical tooth undivided. Small number of labial denticles anterior to sericteries. First and second thoracic segments ventrally with multiple multidentate spinules, arranged in transverse rows. Numbers of ventral setae: six on T1 and T3, four on T2, around six on abdomen (not including anal setae). One pair of setae directly anterior to anal opening, another pair on abdominal segment 9 laterad of anal opening.

Type Material
Lectotype worker (here designated): BRAZIL, Bahia, Sul da Bahia, Áqua Preta, [-8.8333, -66.1667], 1 May 1936, G. Bondar (: 3w; USNMENT01126238, topmost specimen on the pin). Paralectotypes: same data as lectotype (MZSP: 2w; USNMENT01126238, lower two specimens on the pin).