Bembidion mexicanum, Dejean, 1831

Maddison, David & Swanson, Alexander, 2010, A preliminary characterization of Bembidion perspicuum LeConte, with a reclassification of related species (Coleoptera, Carabidae) north of México, ZooKeys 43 (43), pp. 15-31 : 28

B. mexicanum Dejean, 1831

Bembidium mexicanum Dejean, 1831:126 . Type locality México. Lectotype male, designated by Erwin (1982), in MNHN; external structure and aedeagus examined.

Bembidium stabile LeConte, 1879: 508 . Type locality La Veta, Colorado. Lectotype male, designated by Erwin (1984), in MCZ; external structure and aedeagus examined.

Bembidion lugubre vafrum Casey, 1918:60 . Type locality Arizona. Lectotype male, designated by Erwin (1984), in USNM; external structure and aedeagus examined.

Bembidion badiipenne Casey, 1918: 60 . Type locality between Fort Wingate and Jemez Springs, New Mexico. Lectotype female, designated by Erwin (1984), in USNM (type number 36913); external structure examined (spermatheca absent, as most of the abdomen is missing).

This species is known from South Dakota, Colorado, New Mexico, and Arizona, south at least to Guatemala. In the United States, specimens have unicolorous, dark elytra, a smoother pronotum, and tend to be larger than those of B. lugubre ; some specimens from México and Central America have pale elytral apices. The two species can only be reliably distinguished by characters of the male genitalia, female spermatheca, or DNA sequences. The two species are microsympatric, occurring together on the same creek or river shore at numerous localities in Arizona and New Mexico.