Panama, Costa Rica (to Mexico if versuta a junior synonym). Costa Rica: widespread in midmontane to lowland sites.
Kempf 1973 last revised Hylomyrma. Two very similar species were dentiloba, from Panama, and versuta, from Mexico and Belize. He had relatively little Central American material with which to examine character variation, and he suggested that further collecting might reveal continuous variation between the two forms. Several of the characters he used for species distinctions do vary considerably within Costa Rica, as follows.
Dorsal sculpture on mesosoma (Fig. 1, reduced, original). Material from the northern Atlantic lowlands, south to La Selva, and montane sites such as Penas Blancas, Braulio Carrillo National Park above La Selva, and San Vito, have transverse rugae on the anterior pronotum, and a fairly abrupt transition to more longitudinal rugae on the mesonotum. The rugae are variably distinct, with shiny crests emergent from the underlying striolate-punctate sculpture. Material from Rara Avis (a site just south and upslope of La Selva), Carara, and the Osa Peninsula have less organized sculpture, with short, lumpy rugulae overlain by the striolate-punctate sculpture. Material from Hitoy Cerere is intermediate. This is one of the main differentiating features for versuta (distinct rugae) and dentiloba (indistinct rugae). A transition seems to be occurring in Costa Rica, from more dentiloba-like traits in the south to more versuta-like traits in the north.
Sculpture on AT4. versuta and dentiloba varied in the length of the costulae radiating from the postpetiolar insertion. This trait seems highly variable in Costa Rica.
Relative narrowness of compound eye. This is highly variable in Costa Rica, and seems to span the differences used in couplet 10 of Kempf's key.
Sculpture of outer face of tibiae. Most Costa Rican dentiloba have faint traces of striation on tibiae. One specimen from Rara Avis has strongly striate tibiae.
I have chosen to use the name dentiloba for all the Costa Rican material in this group, since it is the older name.
Hylomyrma workers and queens occur in samples of sifted leaf litter from the forest floor. Little else is known about them.
Kempf, W. W. 1973. A revision of the Neotropical myrmicine ant genus Hylomyrma Forel (Hymenoptera: Formicidae). Studia Entomol. 16:225-260.
Found most commonly in these habitats: 488 times found in mature wet forest, 71 times found in lowland rainforest, 74 times found in mesophyll forest, 43 times found in montane wet forest, 31 times found in tropical moist forest, 28 times found in mesophil forest, 24 times found in ridgetop cloud forest, 20 times found in lowland wet forest, 19 times found in 2º lowland rainforest, 17 times found in tropical rainforest, ...
Collected most commonly using these methods or in the following microhabitats: 666 times MiniWinkler, 101 times Winkler, 73 times MaxiWinkler, 33 times Mini Winkler, 9 times Berlese, 4 times Pitfall, 4 times Baiting, 2 times Search & Berles, mushroom baited times PF, 1 times FIT, 1 times flight intercept trap, ...
Elevations: collected from 30 - 1340 meters, 347 meters average