Lachnomyrmex longinoi 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 : 25-27

Lachnomyrmex longinoi Feitosa & Brandão , new species

Figures 9 , 18

Holotype worker. COSTA RICA: Guanacaste: Est. Pitilla, 9km S Sta. Cecília, LN 330200_380200, 16– 18.viii.1993, P. Ríos col., no. INBIOCRI0001657358 [ INBC].

Paratypes. same data as holotype, no INBIOCRI001657147 (1 worker) [ MZSP]; no INBIOCRI0001657202 (1 worker) [ INBC]; COSTA RICA: Alajuela: Río San Lorencito, 1990, P. Hammond col. (2 workers) [ BMNH]; same data (1 worker) [ MZSP]; Guanacaste: Pitilla Field Station, 2.v.1995, R. Anderson col., no. 17721 (1 worker) [ WPMC]; Heredia: La Selva, 15.iv.1985, J. Memmott col. (3 workers) [ BMNH]; Limón: Cerro Cocori, Fca. de E. Rojas, vi.1991, E. Rojas col., no. INBIOCRI000636130 (1 worker) [ INBC]; 30km N Cariari, i.1993, E. Rojas col., no. INBIOCRI000675271 (1 worker) [ INBC]; Puntarenas: Península Osa, Aenn. Fund. Neotrop., 23.vi.1997, R. Anderson col., no. 18686/18687 (5 workers and 1 gyne) [ WPMC]; same data (1 gyne) [ MZSP]; same data (1 worker) [ CASC]; same data (1 worker) [ CPDC]; same data (1 worker) [ USNM]; Cerro Helado, 15km NE Rincón, 24.vi.1997, R. Anderson col., no. 18689 (1 worker and 1 gyne) [ WPMC]; Península Osa, Cerro Helado, 21.vi.1997, R. Anderson col., no. 18685 (2 workers and 1 gyne) [ WPMC].

Worker diagnosis. Body densely and irregularly rugose; metanotal groove obsolete; teeth of propodeal lobes well developed and projected over petiolar peduncle; petiolar node high and subtriangular; pilosity on dorsum of postpetiole exceptionally dense; first tergite of gaster completely devoid of long flexuous hairs.

Holotype measurements. HL 0.72; HW 0.74; ML 0.24; SL 0.43; EL 0.16; WL 0.84; PSL 0.19; PL 0.35; PPL 0.18; GL 0.88; TL 3.21; CI 102; SI 58; OI 21.

Worker measurements (n=20). HL 0.66–0.72; HW 0.65–0.74; ML 0.22–0.25; SL 0.39–0.46; EL 0.13– 0.17; WL 0.76–0.87; PSL 0.16–0.19; PL 0.31–0.36; PPL 0.16–0.19; GL 0.85–0.94; TL 2.98–3.32; CI 98–102; SI 58–66; OI 20–24.

Gyne measurements (n=5). HL 0.65–0.79; HW 0.65–0.79; ML 0.21–0.24; SL 0.39–0.44; EL 0.17–0.20; WL 0.87–1.06; PSL 0.16–0.20; PL 0.36–0.43; PPL 0.17–0.24; GL 0.96–1.12; TL 3.24–3.86; CI 100–102; SI 56–61; OI 26–27.

Worker description. Color dark brown to black, with lighter appendages. Body densely covered by vermiculate short rugae, forming irregular areolae on head and promesonotum, and slightly sparser on mesopleura and lateral surfaces of propodeum; mandibles with short longitudinal striae restricted to basal portion; petiole and postpetiole irregularly rugose. Abundant pilosity on head and promesonotum dorsum; dorsum of petiolar node with about six long hairs; dorsum of postpetiole densely covered by long flexuous hairs; first gastral tergite entirely devoid of long hairs.

Head as long as broad, with vertexal margin weakly convex; frontal lobes subquadrate; eyes with about seven facets on maximum diameter. Promesonotum elevated well above the level of propodeum in profile; metanotal groove virtually obsolete; propodeal spines straight; teeth of propodeal lobes widen basally and slight longer than the half-length of propodeal spines. Petiolar node elevated and subtriangular in lateral view; postpetiole strongly convex dorsally and without ventral projections.

Gyne. Similar to worker. In addition, eyes with around 12 facets at maximum; wings with the basic pattern of venation for the genus; propodeal spines and teeth of propodeal lobes reduced; petiolar node comparatively lower; ventral face of postpetiole moderately projected; surface of first gastral tergite covered by long flexuous hairs, relatively dense anteriorly, becoming sparser posteriorly.

Etymology. This species is named in honor of Dr. John “Jack” Longino in recognition of his many years of devoted work on the ants of Costa Rica and for his valuable support during the elaboration of this work.

Comments. The well developed teeth of propodeal lobes allied to the dense pilosity on postpetiole dorsum separate this species from the related Lachnomyrmex amazonicus , L. nordestinus , L. plaumanni , and L. victori . Gynes of L. longinoi can be confounded with L. scrobiculatus by the subtriangular petiolar node and the presence of long hairs on first gastral tergite. However, gynes of L. scrobiculatus present an anteroventral projection in the postpetiole, which is absent in this species.

Apparently, L. longinoi is commonly encountered in leaf litter samples from wet forests (100–1200 m) of Costa Rica and Panama.

Additional material examined. COSTA RICA: Puntarenas: 3km N Ciudad Neily, 8º41'N 82º57'W, 210m, 31.viii.1985, P.S. Ward col., no. 7771–6 (1 worker, examined by images) [ UCDC]; Carara Biological Reserve, Estación Quebrada Bonita, 30m, 23.vii.1985, J. Longino col., no. INBIOCRI002280159 (1 gyne, examined by images) [ INBC]; Manuel Antonio Nat. Park, 20m, 27.vii.1985, J. Longino col., no. INBIOCRI002280165 (1 worker, examined by images) [ JTLC]. PANAMA: Canal Zone: Barro Colorado, vii-viii.1946, J. Zetek col., no. 5239 (1 worker) [ USNM]; 1976, S. Levings col. (1 worker) [ MIZA]; Chiquiri: Cerro Campana, 5.iv.1995, R. Anderson col., no. 17837 (4 workers) [ WPMC]; same data (1 worker) [ ICNC]; same data (1 worker) [ MZSP]; 20.4km North San Félix, 8.vi.1995, R. Anderson col., no. 17768 (2 workers) [ WPMC].

Figures

FIGURE 9. Worker of Lachnomyrmex longinoi from Puntarenas, Costa Rica: A, head in full face view; B, lateral view; C, dorsal view. Image by April Nobile, specimen PSW 7771 - 6.

FIGURE 18. Distribution maps for the Lachnomyrmex species (L. fernandezi, L. grandis, L. laticeps, L. lattkei, L. longinoi, L. pilosus, and L. platynodus).