Lachnomyrmex mackayi

The only two collections of this species were extracted from the leaf litter of wet montane forests of Panama.

Identification
Feitosa and Brandão (2008) - Body covered by continuous vermiculate rugae; in lateral view, petiolar node considerably elevated and subtriangular; dorsum of postpetiole with more than 10 long hairs; subpostpetiolar process moderately developed; first tergite of gaster with of long flexuous hairs restricted to the anterior third. The absence of a median prominence on the dorsum of postpetiole and the presence of long flexuous hairs on the first tergite of gaster separate this species from the related Lachnomyrmex haskinsi and Lachnomyrmex regularis. In addition, the cited species bear less than 10 long hairs on the postpetiole dorsum. Lachnomyrmex mackayi is also similar to Lachnomyrmex fernandezi; however, the latter has the petiolar node rounded dorsally and the long flexuous hairs covering the entire surface of the first gastral tergite.

Key to Lachnomyrmex

Distribution based on Regional Taxon Lists
Neotropical Region: Panama.

Castes
Known only from the worker caste.

Nomenclature

 *  mackayi. Lachnomyrmex mackayi Feitosa & Brandão, 2008: 27, figs. 10, 19 (w.) PANAMA.

Worker
Holotype HL 0.68; HW 0.65; ML 0.22; SL 0.44; EL 0.17; WL 0.79; PSL 0.18; PL 0.31; PPL 0.17; GL 0.88; TL 3.06; CI 95; SI 68; OI 26. Worker (n=1). HL 0.61; HW 0.60; ML 0.20; SL 0.39; EL 0.14; WL 0.72; PSL 0.16; PL 0.27; PPL 0.14; GL 0.74; TL 2.69; CI 97; SI 66; OI 24.

Color light reddish-brown, with yellowish appendages. Head and mesosoma finely covered by continuous, vermiculate rugae, transverse on anterior portion of pronotum, grading to longitudinal on rest of promesonotum, mesopleura and lateral surfaces of propodeum; mandibles with few and short longitudinal striae restricted to basal portion; petiole and postpetiole irregularly rugose. Abundant pilosity on head and dorsum of promesonotum; petiolar node with about six long hairs; dorsum of postpetiole with more than 10 long hairs; first tergite of gaster with long flexuous hairs restricted to the most anterior portion, near the insertion of postpetiole.

Head slightly longer than broad, with vertexal margin only moderately convex; frontal lobes weakly rounded laterally; eyes comparatively large, with approximately eight facets at greatest diameter. Promesonotum gently convex in profile; metanotal groove relatively narrow and deeply impressed; propodeal spines mostly straight, with apexes minimally directed upwards; teeth of propodeal lobes swollen basally, with about half-length of propodeal spines. Petiolar node elevated and subtriangular in dorsal view; dorsum of postpetiole strongly convex and with a discrete anteroventral projection, directed anteriorly.

Type Material
Holotype worker. PANAMA: Chiriqui: Bocas del Toro, Cont. Div., 9.vi.1995, R. Anderson col., no. 17840, specimen code CASENT0173883 [MCZC]. Paratypes. PANAMA: Chiriqui: 20.4km N. San Félix, 8.vi.1995, R. Anderson col., no. 17767 (1 worker) [WPMC].

Etymology
This species is named after Dr. William “Bill” Mackay, myrmecologist at the University of Texas, El Paso. Mackay sent us important material for this study, including the type series of this species.