Anopheles (Anopheles) eiseni Coquillett

subspecies eiseni Coquillett, 1902a —original combination: Anopheles eiseni. Distribution: Belize, Bolivia, Brazil, Colombia, Costa Rica, Ecuador, El Salvador, French Guiana, Guatemala, Guyana, Honduras, Mexico, Nicaragua, Panama, Peru, Suriname, Trinidad and Tobago, Venezuela (Wilkerson et al. 2021).

subspecies geometricus Corrêa, 1944 —original combination: Anopheles (Anopheles) enseni [sic] subsp. geometricus (varietal status by Stone et al. 1959; original subspecific status re-confirmed by Harbach & Howard 2007). Distribution: Brazil (Corrêa 1944).

Coquillett (1902a) described An. eiseni from a female and two males from Aguna [sic], Guatemala. The female bears a type label and Coquillett’s determination label (Stone & Knight 1956b). Belkin et al. (1965) cited the type locality as Aguná (Escintila), elevation 2,000 ft. The most likely location is Finca Aguná. This estimation is based on the cited elevation that corresponds to one of a number of nearby places with the same name: Coordinates 14.38955 -91.07121 (uncertainty 3,250 m); Municipio de Santa Lucía Cotzumalguapa, Escuintla Province, Guatemala (Chapman & Wieczorek 2020; D. Pecor pers. comm.). Anopheles eiseni sensu lato females have easily recognized morphological characters throughout its reported range: Hindtibia with broad apical band; apex of hindfemur with a few pale scales; costa of wing dark-scaled except for a preapical pale spot on it and vein R 1; sector pale spot only on R 1; apical fringe spot present; scutum with broad pruinose silvery gray central area; proboscis dark; palpomere 5 pale with small dorsal dark spot, palpomere 4 dark laterally, palpomere 3 with narrow apical pale band. There is a wide variety of depictions of wing characters in eiseni sensu lato: Sector pale present on costa (Lane 1953); eiseni sensu stricto with fringe spots at apices of veins R 2, R 3 and R 4+5, but eiseni geometricus without the R 2 fringe spot (Sallum et al. 2020); with pale fringe at apices of all veins and in addition a basal pale fringe spot (Pelaez 1945). Recent observations and photographs of the wing of the holotype female (by D. Pecor) show only preapical pale and sector pale spots as described above, no pale fringe spots. These examples could indicate the presence of a species complex.

Subspecies geometricus was described for specimens from Guarujá, Ilha de Santo Amaro, São Paulo, Brazil. Corrêa (1944) based his description on previously illustrated observations (Corrêa 1942), which were made in comparison to specimens of An. eiseni from Mexico. He noted that the São Paulo “geographical race” was different from specimens from the Guatemala type locality and Mexico. The Guarujá population (eiseni geometricus) was abundant in larval habitats but absent from animal-bait captures and light traps, in contrast to Guatemala, where adults are very easy to find. The primary difference between the two was the morphology of the egg. The egg of geometricus from Guarujá exhibits lozenge-shaped (diamond) features on the outer chorion (thus the name geometricus), while in Mexico (see also Vargas 1942) the outer chorion is smooth with some granular formations at both ends. We assume that the Mexican and Guatemalan specimens are conspecific. Given the great geographical distance between the populations, apparent behavioral differences and distinctive egg features we conclude that geometricus should be afforded species status: Anopheles (Anopheles) geometricus Corrêa, 1944. Anopheles geometricus is currently listed as a species in the Encyclopedia of Life.

Anopheles eiseni has a single synonym, An. niveopalpis Ludlow, 1919 (type locality: Comacho Reservoir, Empire, Canal Zone, Panama). Until proven otherwise, niveopalpis should remain a synonym of An. eiseni.