Portal de Periódicos da CAPES

A New Species of Probolomyrmex (Hymenoptera: Formicidae) from Guanacaste, Costa Rica

1997; BioOne; Volume: 105; Linguagem: Inglês

1937-2361

Sean T. O’Keefe, Donat Agosti,

Animal and Plant Science Education

-Probolomyrmex guanacastensis (n. sp.) from Guanacaste, Costa Rica is described from a queen and worker collected from sifted leaf debris in a riparian habitat. This is the fourth known species of Probolomyrmex in the New World extending the northern distribution limit from Barro Colorado Island, Panama to Guanacaste, Costa Rica. It is also the first record of an ergatoid queen in the Probolomyrmex. A revised key to the species is given. The genus Probolomyrmex was recently revised by Agosti (1994) for South Amer ica and Taylor (1965) for the world. Three species have been described from South America (P. boliviensis Mann from Barro Colorado Island, Panama, and Bolivia; P. brujitae Agosti from Argentina; and P. petiolatus Weber from Barro Colorado Island, Panama). This new species was found while conducting a survey of an ant fauna in riparian habitats near Bagaces, Costa Rica, and represents not only a northern ex tension of the range of members of the genus from southern Panama to northern Costa Rica, but is the first record of this genus for Costa Rica. No further Probol omyrmex spp. were collected in South America, despite extensive leaf litter and soil core samples around Manaus and in the Atlantic Forest in Brazil. The total of more than 2,000 samples so far, which led otherwise to the discovery of extremely rare new species of leptanilloidine ants (Brandao et al., 1998), and the presence of an ergatoid queen, makes it worthwhile to describe this new species. The format follows that of Agosti (1994) and indices were calculated according to Taylor (1965). REVISED KEY TO THE SPECIES OF NEOTROPICAL PROBOLOMYRMEX 1. Petiole in lateral view with a ventral, rectangular process .... ....... petiolatus Weber Petiole in lateral view with a ventral process directed towards the mesosoma .... .... 2 2. Larger body size (TL > 0.95 mm), longer scape (SI > 105). Sculpture with large pits with chagrination in between. First gastral segment ventro-anterior with a distinct collar which is bent ventrally. Head with a distinct carina along the posterior ventral face, which is darker than the adjacent surface. Ventral process of petiole in lateral view distinctly more darkly colored than the tergite boliviensis Mann Small body size (TL < 0.95 mm), short scape (SI < 105). Sculpture fine and densely set. First gastral segment ventrally without a collar. Head with a bulge along the pos terior ventral face, which, in lateral view is not darker than the adjacent surface. Ventral process of petiole in lateral view of the same color as the adjacent tergite .... ...... 3 3. Head smaller (HL 0.57-0.60 mm, HW 0.35-0.36 mm), scape shorter (SL 0.35 mm) brujitae Agosti This content downloaded from 157.55.39.104 on Sun, 19 Jun 2016 06:45:04 UTC All use subject to http://about.jstor.org/terms 1997 NEW PROBOLOMYRMEX FROM COSTA RICA 191