Hylomyrma blandiens

Ulyssea & Brandao (2021) report that Hylomyrma blandiens specimens are usually collected in samples of sifted leaf-litter in tropical rainforest. One Hylomyrma blandiens nest with 24 specimens (3Q 21W) was collected by M.A. Ulysséa in a fallen twig on the ground in the Peruvian Amazon (Madre de Dios, Estación Biológica Villa Carmen). Apart from the specimens, plant remains and parts of a Curculionidae imago were also found inside the nest, but there were no larvae or pupae.

Identification
Ulyssea & Brandao (2021): Head dorsum with regular and longitudinal striae, mesial striation in part directed to posterior margin and in part anteriorly divergent and posteriorly convergent, interspaces distinguishable; mesosoma covered with regular to irregular striae of variable thickness, interspaces indistinguishable; dorsal margin of petiole discontinuous, dorsum with same striation of mesosoma lateral; subtriangular projection on mesoventral surface of petiole; subpostpetiolar process weak, subtriangular; transverse striae on profemur posterior surface; protibia extensor surface striate; long striae on tergum of first gastral segment.

Hylomyrma blandiens, Hylomyrma dentiloba, and Hylomyrma jeronimae have similar morphology. Hylomyrma blandiens was described based on two specimens (worker and queen), and H. dentiloba based on one worker. Hylomyrma blandiens has a broad distribution in northwestern South America, from Bolivia to French Guiana (Fig. 84), whereas H. dentiloba and H. jeronimae are restricted to Central America (Figs. 84, 86).

Hylomyrma blandiens can be distinguished from H. dentiloba (characteristic in parentheses) in the distinguishable interspaces on head dorsum striation (vs. indistinguishable interspaces), the convex dorsal margin of mesonotum (vs. straight), the propodeal spine slightly longer than the dorsal tooth of propodeal lobe (vs. shorter), and the striae length on the first gastral segment similar to the postpetiole length (vs. shorter than the postpetiole length). Hylomyrma blandiens can be distinguished from H. jeronimae in the regular striae on the mesial region of head dorsum in part directed to posterior margin and in part anteriorly divergent and posteriorly convergent (vs. regular to irregular striae and divergent), the drop-shaped eye (vs. reniform), the longitudinal striation on the mesosomal dorsum (vs. striae assuming multiple directions), the discontinuous dorsal margin of petiole (vs. continuous), and the striae on the tergum of the first gastral segment extending up to its first third (vs. restricted to its basal region). Also, H. blandiens resembles H. macielae in the regular divergent-convergent striae on the mesial region of head dorsum, and the indistinguishable interspaces on the mesosomal striation. Hylomyrma blandiens can be distinguished from H. macielae in the longitudinal striae on the mesosomal dorsum (striae assuming multiple directions in H. macielae). The western limit of the distribution of H. blandiens, the east side of The Andes in Ecuador and Colombia (Fig. 84), overlaps in part with the distribution of H. macielae (Fig. 86).

There is morphological variation across the range of H. blandiens. Specimens from Ecuador have longer propodeal spines than elsewhere in the range. Specimens from Ecuador and Tachira, Venezuela, have a more pronounced mesoventral projection on the petiole. Striae on the mesial area of the head dorsum vary from being longitudinal to somewhat angled, divergent anteriorly and convergent posteriorly.

Distribution based on Regional Taxon Lists
Neotropical Region: Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Panama, Peru, Suriname, Trinidad and Tobago, Venezuela.

Nomenclature

 * . Hylomyrma blandiens Kempf, 1961b: 500, fig. 8 (w.q.) SURINAME.
 * Type-material: holotype worker, 1 paratype queen.
 * Type-locality: holotype Suriname: Dirkshoop, v.1959, soil sample, primary forest (J.v.d. Drift); paratype Suriname: La Poulle, viii.1959, soil sample, shrub on sand (J.v.d. Drift).
 * Type-depository: MZSP.
 * Ulysséa & Brandão, 2021: 31 (m.).
 * Status as species: Kempf, 1964e: 55 (in key); Kempf, 1972a: 118; Kempf, 1973b: 231 (redescription); Kempf, 1975c: 346; Kutter, 1977a: 88; Brandão, 1991: 347; Bolton, 1995b: 213; Bezděčková, et al. 2015: 117; Pierce, M.P., Branstetter, et al. 2017: 137; Fernández & Serna, 2019: 797; Ulysséa & Brandão, 2021: 28 (redescription).
 * Distribution: Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Panama, Peru, Suriname, Trinidad, Vemezuela.

Type Material

 * Holotype: SURINAM[E: Saramacca]: Dirkshoop, v.1959, I.v.d. Drift col., [soil sample from primary forest], 27-iiicd-10 (1W) (ANTWEB-1008990 MZSP67313) [MZSP] [examined by Ulyssea & Brandao (2021)].
 * Paratype: SURINAM[E: Saramacca]: La Poulle, viii.1959, I.v.d. Drift col., [soil sample from shrub on sand], 31-xivb-8 (1Q) (MZSP67314) [MZSP] [examined by Ulyssea & Brandao (2021)].

References based on Global Ant Biodiversity Informatics

 * Brandao, C.R.F. 1991. Adendos ao catalogo abreviado das formigas da regiao neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412.
 * Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
 * Franco W., N. Ladino, J. H. C. Delabie, A. Dejean, J. Orivel, M. Fichaux, S. Groc, M. Leponce, and R. M. Feitosa. 2019. First checklist of the ants (Hymenoptera: Formicidae) of French Guiana. Zootaxa 4674(5): 509-543.
 * Kempf W. W. 1961. A survey of the ants of the soil fauna in Surinam (Hymenoptera: Formicidae). Studia Entomologica 4: 481-524.
 * Kempf W. W. 1973. A revision of the Neotropical myrmicine ant genus Hylomyrma Forel (Hymenoptera: Formicidae). Studia Entomologica 16: 225-260.
 * Kempf W. W. 1975. Miscellaneous studies on neotropical ants. VI. (Hymenoptera, Formicidae). Studia Entomologica 18: 341-380.
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Pierce M. P., M. G. Branstetter, and J. T. Longino. 2017 . Integrative taxonomy reveals multiple cryptic species within Central American Hylomyrma FOREL, 1912 (Hymenoptera: Formicidae). Myrmecological News 25: 131-143.