Gnamptogenys caelata, Kempf, W. W., 1967

Kempf, W. W., 1967, New ants from southeastern and central Brazil (Hymenoptera, Formicidae)., Studia Entomologica (N. S.) 9, pp. 121-128 : 121-122

Gnamptogenys caelata n. sp.

(Figs. 1-3)

Worker (holotype). - Total length 2.9 mm; head length 0.61 mm; head width 0.50; maximum diameter of eyes 0.13 mm; thorax length 0.83 mm; petiole length 0.29 mm; petiole width 0.39 mm; tergum I of gaster (postpetiole) length and width 0.56 mm; tergum II of gaster length 0.56 mm. Reddish brown; antennae, legs and apical segments of gaster medium brown. Abundant, yellowish and moderately long standing hairs on body; oblique or appressed hairs on scapes and legs, which also bear copious pubescence.

Mandibles triangular, chewing border finely denticulate; blades laterally coarsely rugose and punctate, mesially along chewing border smooth and shining. Head capsule (Fig. 1) elongate, sides slightly converging cephalad, occipital border vestigially impressed in the middle. Clypeus: anteriorly with a small denticle; traversed by a few longitudinal costae, the mesial one much stronger than the lateral ones. Frontal carinae widely separated from each other, the rounded lateral lobes almost attaining the lateral border, constricted and fading out above eyes. The latter very large, moderately convex, with about 8 facets across the greatest diameter. Dorsum of head coarsely longitudinally costate and sulcate, the costae somewhat vermiculate in front, straightening out toward the rear where they diverge slightly laterad and curve downward, the medial ones on occiput, the lateral ones on the sides in front of the occipital corner; about 20 costae between frontal carinae at the level of eyes. Sides of head longitudinally costate beneath eyes. Costae on gular face more vermiculate, curving mesad in front where they join up with the costae coming from the opposite side. Antennal scapes nearly attaining the occipital corner, reticulate-rugose. Funicular segments II1-VIII greatly transverse, I longer than broad, II, IX and X about as long as broad, XI twice as long as broad.

Thorax as shown in Fig. 2. Dorsum longitudinally costate, about 20 costae above on pronotum which bears in front about 4 slightly vermiculate transverse costae; approximately 14 costae above on basal face of epinotum. No dorsal sutures apparent. Sides of thorax coarsely and horizontally costate, costae quite regular. Epinotal teeth small. Declivous face baso-laterally longitudinally costate, costae curving mesad above and in the middle, fusing with those coming from the opposite side. Fore coxae sharply horizontally costate, middle and hind coxae somewhat reticulate-punctate and superficially to vestigially costate. Hind coxae with a minute but acute basidorsal tooth. Femora and tibiae smooth and shining.

Petiole as shown in Figs. 2 and 3. Node transversely vermiculate-costate in front and on sides, dorsum with transversely arched costae. Posterior face, above gastric insertion, smooth and shining, with a few arching transverse costae. Tergum I and II of gaster regularly and longitudinally costate, sternum I with costae that curve mesad behind, more irregular, interspersed with coarser punctures.

Specimen examined: 1 worker (holotype), collected in April 1965, at Iguacu, Parana State, souteastern Brazil, by F. Plaumann (WWK n. 4117).

Discussion. - The present species is very close to striolata (Borgmeier) , exhibiting the following differences: Size significantly smaller; compound eyes much larger; petiole and tergum I of gaster costate and not coarsely punctate; antennal scapes shorter, barely attaining the occipital corner; tergum II of gaster as long as tergum I; subpetiolar process weakly bidentate, excavate between anterior and posterior tooth; sternum II of gaster continuous from side to side, not completely reduced in the middle.

It is interesting to note that caelata is somewhat intermediate between striolata and the more orthodox species of Gnamptogenys .