Butterflies of Zihuatanejo

SUPERFAMILY PAPILIONOIDEA

-Typical Blues (Tribe Polyommatini)

-Subtribe Brephidiina

-Pygmy-Blues (Genus Brephidium)

-Western Pygmy-Blue (Brephidium exilis)

-Common Western Pygmy Blue (Brephidium exilis ssp. exilis)

Brephidium exilis, commonly known as the Western Pygmy Blue, is the smallest butterfly in North America and one of the smallest in the world. It belongs to the family Lycaenidae and has a wingspan of only about 12–20 mm. The upper side of the wings is typically brown with a subtle bluish sheen near the base, while the underside is more distinctive—pale gray or tan with rows of tiny black spots, often accompanied by a hint of coppery or bluish scaling near the body. Despite its size, it can be quite active, fluttering close to the ground. Adults are often seen low to the ground, visiting very small flowers or resting on vegetation.

Diet

Adults: Feed on flower nectar from small flowering plants.
Caterpillars: Feed primarily on salt-tolerant plants, especially saltbushes (Atriplex). The caterpillars consume leaves and other portions of the host plant.

Range

Brephidium exilis has an exceptionally broad range for such a tiny butterfly, extending from the western and southwestern United States through Mexico and Central America into northern South America, including Venezuela.
Around Zihua, Brephidium exilis would likely be considered rare to occasional, because suitable salt-tolerant or alkaline vegetation is relatively localized around the Zihuatanejo area.

Habitat

Strongly associated with alkaline, saline and otherwise sparsely vegetated habitats, including salt marshes, coastal flats, alkaline soils, wasteland and disturbed areas where its host plants grow.
Around Zihua, the best places to look would be coastal salt-influenced vegetation, saline flats, estuarine margins and disturbed patches containing Atriplex, Suaeda, Salicornia or related plants.
Its tiny size allows it to occupy very small patches of suitable habitat that might easily be overlooked.

Size