Strumigenys mariae

Sosa-Calvo et al. (2010) - The four specimens known of S. mariae were collected in a leaf-litter sample extracted with a mini-Winkler. The sample was collected in a primary lower montane forest (1300 m). Other species in the gundlachi-group have been recorded from wet forest habitats and from lowland rainforest to cloud forest and some in agroecosystems. Strumigenys denticulata, the species perhaps most closely related to S. mariae, has been collected in lowland (< 1000 m) forests in Panama (Sosa-Calvo et al. 2006) to subtropical forests in the wet Chaco region of Argentina (Theunis et al. 2005). Nothing is known about the biology of S. mariae other than the collection data.

Identification
Sosa-Calvo et al. (2010) - Mandibles linear, elongate, and narrow; inner margin of mandibles with two clearly defined teeth, which are larger than the rest; labral lobes short with long trigger hairs at their apices; metapleuron smooth and shining; ventral portions of petiole and postpetiole lacking spongiform tissue.

Strumigenys mariae is clearly a member of the gundlachi-group (refer to Bolton [2000: 176–179 p.] for further information). Within the gundlachi-group, Bolton (2000) identified two complexes, Strumigenys crassicornis and Strumigenys gundlachi. Strumigenys mariae belongs to the gundlachi-complex and resembles Strumigenys denticulata, Strumigenys enopla, and Strumigenys vartana. Strumigenys mariae shares with S. vartana the smooth and shining mesopleuron and metapleuron, but S. mariae can be distinguished from S. vartana by the form of the apicoscrobal and pronotal humeral hairs, both short and stiff (mariae) rather than long and filiform (vartana), and the disc of the postpetiole is reticulate (mariae) rather than smooth and shining (vartana).

Strumigenys mariae is of similar size and color as S. enopla. However, S. mariae differs from S. enopla in that the apicoscrobal, humeral, and mesonotal hairs are short, erect, and stiff (mariae) rather than long and filiform (enopla); the metapleuron is smooth and shining (mariae) rather than reticulate (enopla); the dorsum of the petiole bears a single pair of hairs (mariae) rather than two pairs of hairs (enopla); and the dorsum of the postpetiole lacks an anterior pair of hairs (mariae), present in enopla.

Strumigenys mariae can easily be confused with Strumigenys denticulata with which it shares the most character states. However, the species can be separated by: (i) mandibular dentition: S. denticulata has 5–10 preapical denticles of similar size, whereas S. mariae has 3–4 preapical denticles, two of which are larger than the rest. In Strumigenys mariae, at least in the four specimens examined, there are 4 teeth on the left mandible and 3 teeth on the right mandible; (ii) mesosomal sculpture: the metapleuron in S. denticulata is reticulate, whereas in S. mariae it is smooth and shining; (iii) petiole proportions: the petiolar peduncle in S. denticulata is relatively shorter (PI 38–42) than in S. mariae (PI 43–49).

Distribution based on Regional Taxon Lists
Neotropical Region: Guyana.

Castes
Known only from the worker caste.

Nomenclature

 *  mariae. Pyramica mariae Sosa-Calso, Schultz & LaPolla, 2010: 18, figs. 6, 8, 10 (w.) GUYANA. Combination in Strumigenys: unpublished.

Worker
Holotype (and paratype): GL = 0.59 (0.48), HL = 0.52 (0.48–0.50), HW = 0.42 (0.38–0.46), ML = 0.36 (0.36–0.38), PL = 0.28 (0.24–0.27), PPL = 0.12, PW = 0.27 (0.23–0.24), SL = 0.30 (0.30– 0.31), TL = 2.47 (2.24–2.28), WL = 0.58 (0.55–0.56). Indexes: CI = 81 (78–92), MI = 73 (72–75), PI = 48 (43–49), SI = 71 (65–82). (n = 4)

Possessing characters of the gundlachi-group and gundlachi-complex (Bolton 2000). Head: in full-face view nearly as broad as long; inner margin of elongate mandibles slightly concave to more or less straight, with 4 teeth on left mandible and 3 on right mandible, of which a pair of teeth are larger on each mandible (same in paratypes); with 2 minute intercalary denticles between apicodorsal and apicoventral fork teeth; labral lobes short, almost invisible in full-face view; trigger hairs long; eyes with 3 ommatidia in longest row, with 6–7 ommatidia in total. Cephalic dorsum with two pairs of erect hairs: one pair located close to occipital margin and another pair located close to highest point of vertex; each upper scrobal margin with a short apicoscrobal hair that projects laterally. Mesosoma: pronotum with a pair of short humeral hairs that project laterally; mesonotum with a pair of short, erect, stiff hairs; mesopleuron and metapleuron mostly smooth and shining; dorsum of promesonotum, propodeum, and propodeal declivity strongly reticulate. Metasoma: peduncle of petiole long, length of petiole 3–3.5 times longer than its disc; petiolar disc reticulate-punctate, with a pair of erect hairs on posterior portion of disc; ventral portion of petiole lacking spongiform tissue; disc of postpetiole reticulate, ventral portion of postpetiole lacking spongiform tissue; posterior portion of postpetiole disc with a row of 4 erect hairs; first gastral tergite almost entirely reticulate except for a small portion at posterior portion of tergite. Individuals light brown to brown.

Type Material
Holotype: worker, labeled ‘‘GUYANA: Mt. Ayanganna montane forest; 1300 m; 59u 57.9699 W 5u 22.4839 N; 13.x.2002; T. R. Schultz, J. LaPolla, C. Marshall, R. Williams; litter sample.’’ USNM ENT No. 00413858. . Paratypes: 3 workers, same locality as in holotype. USNM ENT No. 00413859, 00442882, 00442883. .

Etymology
Named in honor of the first author’s mother, Maria del Carmen Calvo, in gratitude for her encouragement and support.

References based on Global Ant Biodiversity Informatics

 * Sosa-Calvo J., T. R. Schultz, and J. S. LaPolla. 2010. A review of the dacetine ants of Guyana (Formicidae: Myrmicinae). Journal of Hymenoptera Research 19: 12-43.