Lachnomyrmex mackayi Feitosa & Brandão, 2008

Feitosa, Rodrigo M. & Brandão, Carlos Roberto F., 2008, A taxonomic revision of the Neotropical myrmicine ant genus Lachnomyrmex Wheeler (Hymenoptera: Formicidae), Zootaxa 1890, pp. 1-49 : 27

Lachnomyrmex mackayi Feitosa & Brandão , new species

Figures 10 , 19

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].

Worker diagnosis. 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.

Holotype measurements. 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 measurements (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.

Worker description. 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.

Gyne. Unknown.

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.

Comments. 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 L. regularis . In addition, the cited species bear less than 10 long hairs on the postpetiole dorsum. Lachnomyrmex mackayi is also similar to L. fernandezi ; however, the latter has the petiolar node rounded dorsally and the long flexuous hairs covering the entire surface of the first gastral tergite.

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

Figures

FIGURE 10. Holotype worker of Lachnomyrmex mackayi from Chiriqui, Panama: A, head in full face view; B, lateral view; C, dorsal view. Image by Michele Esposito, specimen CASENT 0173883.

FIGURE 19. Distribution maps for the Lachnomyrmex species (L. haskinsi, L. mackayi, L. nordestinus, L. plaumanni, L. regularis, and L. scrobiculatus).