Lachnomyrmex victori 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 : 43-48

Lachnomyrmex victori Feitosa & Brandão , new species

Figures 17 , 20

Holotype worker. BRAZIL: Santa Catarina: São Bonifácio, P.E. da Serra do Tabuleiro, 27º49'06''S 48º54'41''W, 8–13.iii.2004, R.R. Silva, B.H. Dietz & N.L. Albuquerque cols, no. 27 [ MZSP].

Paratypes. same data as holotype, nos. 3/27 (3 workers and 1 gyne) [ MZSP]; same data, no. 27 (1 worker) [ CASC]; BRAZIL: Espírito Santo: Santa Teresa, E.B. Santa Lúcia, 19º58'09''S 40º32'15''W, 20– 24.i.2002, J.H. Schoereder & C.R. Ribas cols, no. 37 (2 workers) [ MZSP]; same data, no. 37 (1 worker) [ USNM]; Santa Catarina: Blumenau, P.E. das Nascentes, 27º06'15''S 49º09'14''W, 20–27.x.2000, R.R. Silva & F. Eberhardt cols, nos. 13/17/20/24 (4 workers) [ MZSP]; Paraná: Tunas, P. das Lauráceas, 24º51'16''S 48º43'00''W, 21–29.ii.2001, R.R. Silva & F. Eberhardt cols, nos. 7/ 9/11/13 /17/28/50 (6 workers e 1 gyne) [ MZSP]; same data, no. 7 (1 worker) [ AMNH]; same data, no. 7 (1 worker) [ BMNH]; same data, no. 7 (1 worker) [ ICNC]; same data, no. 7 (1 worker) [ IHVL]; same data, no. 9 (1 worker) [ INBC]; same data, no. 28 (1 worker) [ MIZA]; São Paulo: Salesópolis, E.B.B., 12–17.iv.1997, B.H. Dietz & C. I. Yamamoto cols, nos. 4/24 (2 workers and 1 gyne) [ MZSP]; same data, no. 7 (1 worker) [ WPMC]; same locality, 20–26.x.1997, C. Klingenberg & C.I. Yamamoto cols, no. 22 (1 worker) [ MZSP].

Worker diagnosis. Body irregularly covered by vermiculate, short, relatively sparse rugae; promesonotum moderately convex; metanotal groove shallowly impressed to obsolete; propodeal spines straight; teeth of propodeal lobes reduced and swollen basally; dorsum of postpetiole with more than 10 long hairs; first tergite of gaster devoid of long flexuous hairs.

Holotype measurements. HL 0.73; HW 0.72; ML 0.24; SL 0.47; EL 0.14; WL 0.85; PSL 0.17; PL 0.36; PPL 0.14; GL 0.98; TL 3.30; CI 98; SI 66; OI 20.

Worker measurements (n=33). HL 0.52–0.76; HW 0.54–0.76; ML 0.16–0.25; SL 0.30–0.51; EL 0.08– 0.16; WL 0.57–0.93; PSL 0.11–0.21; PL 0.22–0.39; PPL 0.12–0.19; TL 2.26–3.51; GL 0.68–1.02; CI 97–103; SI 51–66; OI 15–22.

Gyne measurements (n=9). HL 0.69–0.78; HW 0.69–0.79; ML 0.21–0.26; SL 0.44–0.49; EL 0.18–0.21; WL 0.85–1.06; PSL 0.16–0.22; PL 0.35–0.41; PPL 0.13–0.18; GL 0.94–1.17; TL 3.21–3.83; CI 99–101; SI 61–66; OI 24–279.

Worker description. Body reddish-brown to black, with gaster and appendages slightly lighter. Body irregularly covered by short, relatively sparse rugae, somewhat longer and longitudinal on head dorsum; mandibles with short longitudinal striae restricted to basal portion; petiole and postpetiole finely and irregularly rugose. Abundant pilosity on head and promesonotum dorsum; dorsum of petiolar node and postpetiole each with more than 10 long hairs; first gastral tergite entirely devoid of long flexuous hairs.

Head usually as long as broad, with vertexal margin moderately convex; frontal lobes laterally rounded; eyes with about seven facets on maximum diameter. Promesonotum moderately convex in profile, but distinctly higher than propodeum level; metanotal groove shallow to virtually obsolete; propodeal spines straight; teeth of propodeal lobes swollen and very reduced, with less than one-third of propodeal spines length. Petiolar node moderately elevated, dorsally rounded, and with the posterior face weakly sloped in lateral view; postpetiole weakly convex dorsally and without ventral processes.

Gyne. Differing from worker by the following combination of characters: body pilosity denser and shorter, with first tergite of gaster bearing around 10 long flexuous hairs at the anterior portion, near postpetiole insertion; eyes with around 13 facets at greatest diameter; petiolar node comparatively lower.

Etymology. The name of this species is an homage to Victor Vieira da Silva, son of the colleague myrmecologist Rogério Rosa da Silva.

Comments. While examining specimens of Lachnomyrmex plaumanni from the MZSP collection, one of us (RMF) noticed that there was a morphologically distinct subgroup of individuals, all collected in the same range of L. plaumanni . In the pin of one of these individuals there was a manuscript note made by Father Thomas Borgmeier in which he recognized a group of workers that differed from the typical L. plaumanni by the larger size and straight propodeal spines, rather than the curved ones of the latter. The study of recently collected Lachnomyrmex specimens deposited in the MZSP collection, led us to recognize these specimens and several others as a different and undescribed species sympatric with L. plaumanni .

Further than the characters pointed out by Borgmeier, workers of L. victori can be distinguished from L. plaumanni and the other congeners also by the promesonotum only moderately elevated, metanotal suture ill impressed, dorsum of postpetiole with more than 10 long hairs, and first gastral tergite devoid of long hairs.

As far as we know, L. victori occurs in the Atlantic Forest of southeastern Brazil, at 300–1050m elevation. As in L. plaumanni , there is a single record of a L. victori worker foraging in the vegetation. It was collected on the trunk of Croton floribundus (Euphorbiaceae) , in the state of São Paulo (M.S. Morini, pers. comm.).

Additional material examined. BRAZIL: Bahia: Ilhéus, iv.1996, J. Assis col. (1 gyne) [ CPDC]; same locality, x.1996, L.S. Ramos col., no. 5119 (2 workers) [ CPDC]; Maraú, 23.x.1998, J.R.M. Santos col. (1 worker) [ MZSP]; São José, Vitória Puaias, 15º03'N 39º20W, 22.v.2000, J.R.M. Santos col., no. A38 (1 worker) [ CPDC]; Paraná: Bocaiúva, v.1963, F. Plaumann col., no. 4000 (1 gyne) [ MZSP]; same locality, xi.1963, F. Plaumann col., no. 3870 (1 worker) [ MZSP]; Santa Catarina: Chapecó, vi.1960, F. Plaumann col. (1 gyne) [ MZSP]; Concórdia, ix.1959, F. Plaumann col., no. 8296a (1 worker) [ MZSP]; Ibicaré, vii.1959, F. Plaumann col., no. 3128 (4 workers) [ MZSP]; Nova Teutônia, ix.1954, F. Plaumann col., no. 8216 (4 workers and 2 gynes) [ MZSP]; same locality, xi.1957, F. Plaumann col. (1 worker) [ MZSP]; same locality, xii.1958, F. Plaumann col., no. 8307 (1 worker) [ MZSP]; same locality, vii.1959, F. Plaumann col. (1 worker) [ MZSP]; same locality, vi.1960, F. Plaumann col., no. 3960 (1 worker and 1 gyne) [ MZSP]; same locality, vi.1963, F. Plaumann col., no. 3710 (1 gyne) [ MZSP]; Seara, viii.1958, F. Plaumann col., no. 2708 (3 workers) [ MZSP]; same data (1 worker) [ MZSP]; São Paulo: Cunha, P.E. da Serra do Mar, Núcleo Indaiá, 23º15'03''S 45º00'26''W, 21–22.iv.2001, R.R. Silva & A.A. Tavares cols, no. 31 (3 workers) [ MZSP]; Mogi das Cruzes, P.N.M. da Serra do Itapeti, Trilha do Esquilo, 22.iv.1999, 23º29'22''S 46º11'55"W, A.S.M. Cassarotti col., no.

C2.2 (1 worker) [ CPMS]; Ribeirão Grande, P.E. Intervales, Barra Grande, 24º18'30''S 48º25'10''W, 5.ii.1999, A.A. Tavares col., no. T2–15 (1 gyne) [ MZSP].

Figures

FIGURE 17. Paratype worker of Lachnomyrmex victori from Santa Catarina, Brazil: A, head in full face view; B, lateral view; C, dorsal view. Image by Michele Esposito, specimen CASENT 0173877.

FIGURE 20. Distribution map for the Lachnomyrmex species (L. amazonicus, L. longinodus, and L. victori).