Lachnomyrmex haskinsi Smith, 1944

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 : 17-19

Lachnomyrmex haskinsi Smith, 1944

Figures 5 , 19

Lachnomyrmex haskinsi Smith, 1944: 227 , figs. 1–2. Holotype worker, Panama: Canal Zone, Barro Colorado Island, iiiii.1994, J. Zetek col., no. 5121/56906 [USNM] (examined).

Worker diagnosis. Body covered by continuous vermiculate rugae; petiolar node considerably elevated and subtriangular; dorsum of postpetiole with about six long hairs, and with a raised prominence medially; subpostpetiolar process present and well developed; first tergite of gaster devoid of long hairs.

Holotype measurements. HL 0.60; HW 0.55; ML 0.22; SL 0.38; EL 0.09; WL 0.68; PSL 0.11; PL 0.24; PPL 0.13; GL 0.79; TL 2.65; CI 92; SI 68; OI 17.

Worker measurements (n=2). HL 0.61–0.65; HW 0.60–0.63; ML 0.21–0.24; SL 0.39; EL 0.11–0.13; WL 0.71–0.74; PSL 0.16–0.17; PL 0.25–0.30; PPL 0.13–0.14; GL 0.79–0.80; TL 2.70–2.94; CI 97–98; SI 62–66; OI 17–21.

Worker description. Color red ferruginous to brown, with lighter appendages. Head and mesosoma finely covered by continuous vermiculate rugae, transverse on anterior portion of pronotum, grading to longitudinal on the rest of promesonotum, mesopleura and lateral faces of propodeum; mandibles with few and short longitudinal striae restricted to basal portion; petiole and postpetiole finely and irregularly rugose. Abundant pilosity on head and dorsum of promesonotum; dorsum of petiolar node and postpetiole with about three and six long hairs, respectively; first tergite of gaster entirely devoid of long flexuous hairs.

Head longer than broad, with vertexal margin convex; frontal lobes slightly rounded laterally; eyes with six to seven facets at greatest diameter. Promesonotum evenly convex in profile; metanotal groove relatively narrow and deeply impressed; propodeal spines straight; teeth of propodeal lobes widen basally, with about half-length of propodeal spines length. Petiolar node strongly elevated and subtriangular in lateral view; dorsum of postpetiole with a raised prominence medially and a well developed anteroventral projection directed anteriorly.

Gyne (first description). Differing from worker by having about 12 facets at eyes maximum diameter; dorsum of petiolar node and postpetiole with about five and 10 long hairs, respectively; first tergite of gaster with around 10 long flexuous hairs on the anterior third, near postpetiolar insertion (see picture in the “Ants of Costa Rica ” website).

Etymology. Dr. Marion M. Smith (1944) named this species in honor of Dr. Caryl Parker Haskins (1908– 2001), in recognition for his contribution to the study of ant biology.

Comments. This species is most similar to Lachnomyrmex regularis , but can be easily distinguished from the latter by the smaller size, more irregular rugulation, and presence of fine short rugae on postpetiole dorsum. Workers of L. fernandezi and L. mackayi can also be confounded with L. haskinsi , but they present long flexuous hairs at least on the anterior third of the first gastral tergite.

Lachnomyrmex haskinsi has been recorded from Costa Rica and Panama, in 200–800m elevation wet forests. Workers are usually collected in samples of sifted leaf litter. Dr. John Longino observed a few workers, one with a larva, scattered throughout the debris of a Brachymyrmex nest he was collecting from beneath rotten wood on the forest floor ( Longino 2007).

Additional material examined. COSTA RICA: Alajuela: Río San Lorencito, 1990, P. Hammond col. (1 worker) [ BMNH]; Heredia: La Selva Biological Station, CCL, 10º43’N 84º01’W, 15.vii.1986, J. Longino col., no. INBIOCRI002280138 (1 worker) [ INBC]; same locality, 23.x.1991, J. Longino col., no. INBIOCRI001237374 (1 gyne, examined by images) [ INBC]; Limón: Cerro Cocori, Fca. de E. Rojas, 9– 30.xi.1992, E. Rojas col., no. INBIOCRI000900198 (1 worker) [ MZSP].

Figures

FIGURE 5. Worker of Lachnomyrmex haskinsi from Heredia, Costa Rica: A, head in full face view; B, lateral view. Image by John Longino, specimen INBIOCRI 001237374.

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