Lasius mexicanus

Distribution
Known from Hidalgo and Puebla, Mexico.

Distribution based on Regional Taxon Lists
Neotropical Region: Mexico.

Biology
Wing (1968) – Type collections were made within a radius of a couple of miles of an ore mill, which was situated on the eastern slope of the high mountain range east of Pachuca. This country was covered with woods, mostly oaks and pines. The area around the mill was dry at certain times of the year; the altitude was between 8500 and 9000 feet. The type series includes specimens from more than one nest; all were collected from under large stones, mostly in pine woods. No habitat data other than altitude are available for the other two collections. The single queen was collected at 7900 feet, the nest of workers at 8600 feet.

Alate dates - The type alates were taken sometime during May 1913, while the Carney queen was collected June 16. This species begins its flights relatively early in the season.

This species is likely to be a temporary parasite, but its host is.

Nomenclature

 *  mexicanus. Lasius (Acanthomyops) interjectus subsp. mexicanus Wheeler, W.M. 1914b: 55 (w.q.m.) MEXICO. Wheeler, G.C. & Wheeler, J. 1970: 648 (l.). Combination in Acanthomyops: Wing, 1968: 146; in Lasius: Ward, 2005: 13. Raised to species: Buren, 1950: 185.

Worker
Wing (1968) – Closely similar to Lasius occidentalis, but petiolar scale broader, its width across spiracles clearly greater than height from spiracle to crest. Dorsum of gaster with pubescence dilute to moderate and long, its surface shining. In profile, propodeum usually distinctly convex. Posterior border of head as seen in full-face view straight or nearly so. Crest of petiolar scale usually emarginate, sides often convex.

Color yellow.

Queen
Wing (1968) – Similar to occidentalis, but posterior border of head as seen in full-face view straight or nearly so. Scutellum completely covered with long, dilute pubescence. Width of petiolar scale across spiracles clearly greater than height from spiracle to crest. Crest and sides of scale with fewer standing hairs. Pubescence over dorsum of gaster dilute, thinner on posterior surface than anteriorly. An occasional specimen may have pubescence moderate to moderately dense and more irregularly distributed. In all cases the gaster is at least moderately shiny. CI 100 or more.

Color brown to yellowish brown.

Male
Wing (1968) – Similar to occidentalis, but much larger; AL 1.40 mm or more, SL 0.60 mm or more. Scutellum entirely covered with dilute long pubescence. Pilosity at posterior tip of gaster with longer hairs measuring 0.20 mm or more. Petiolar scale broad, crest emarginate.

Pubescence on gaster dilute, surface shining. Body color brown, head darker, appendages lighter.

Type Material
Wing (1968) – Type locality: Guerrero Mill, State of Hidalgo, Mexico. Location of types: Syntypes in the.