Larvae of boisduval's blue are extremely small and rarely seen. The males' top wing grades from ice blue in the center to deep sky blue, exhibiting a dazzling iridescent fluctuation in range under direct, full sunlight. Black margins on the upper wing sport long, white, hair-like scales. A constellation of jet-black dots frames the extremities of the ventral surface, its pattern adroitly complementing the wing shape and throwing it into spectacular relief against the shimmering silvery pearlescent background. A fascinatingly muted hint of dark ice blue bleeds faintly up from the body, permeating the veins throughout for the palest, most delicate emphasis. The body shape, eyes, antennae, and appendages give it a uniquely exquisite poise. The males' bodies are dark-blue or brown. The females' upper wings are dark brown but otherwise mirror the males'.

Icaricia lupini, the lupine blue, is a butterfly of the family Lycaenidae. It is found from south-western Canada, south through much of mountainous and intermountain western United States and high plains to northern Mexico. The wingspan is 22–29 mm. Adults are on wing from June to August in one generation in the Sierra Nevada of eastern California. Elsewhere, there are several generations from March to July. The larvae feed on Eriogonum umbellatum and Eriogonum fasciculatum. Adults feed on flower nectar. The hairs of the caterpillars can cause skin irritation (urticaria).

Icaricia shasta, the Shasta blue, is a butterfly of the family Lycaenidae. It is found from the northwestern United States to southern Saskatchewan and Alberta. The wingspan is 20–22 mm. Adults are on wing from June to August. The larvae feed on Lupinus lyalli, Astragalus spatulatus, Astragalus calycosus, and Trifolium dasphyllum.

Icaricia saepiolus, the greenish blue, is a butterfly of the family Lycaenidae. It is found from the northwestern United States to southern Saskatchewan and Alberta. The wingspan is 21–28 mm. Adults are on wing from June to August. The larvae feed on Trifolium monathum, Trifolium longipes, and Trifolium wormskioldii.

The endangered Mission blue has a wingspan around 21–33 millimetres (0.83–1.3 in). Larvae are extremely small and rarely seen. The males' top wing grades from ice blue in the center to deep sky blue (misregistered as turquoise/cyan to violet by most photographic equipment, the wing color carries no hint of green or purple, strictly capturing an enthralling spectrum of purest, clearest, richest, brightest blue) exhibiting a dazzling iridescent fluctuation in range under direct, full sunlight. Black margins on the upper wing sport "long, white, hair-like scales". A constellation of jet-black dots (misregistered as dull gray by most photographic equipment) frames the extremities of the ventral surface, its pattern adroitly complimenting the wing shape thrown into spectacular relief against the shimmering silvery pearlescent background, with a fascinatingly muted hint of dark ice blue bleeding faintly up from the body and permeating the veins throughout for the palest, most delicate of emphases. Body shape, eyes, antennae, and appendages possess it of a uniquely exquisite poise. The males' bodies are dark-blue/brown. Females' upper wings are dark brown, but otherwise mirror males'. The larvae only feed on the leaves of the three host lupine plants (Lupinus albifrons, Lupinus formosus, and Lupinus variicolor) native to their habitat. The plants are necessary for survival for the Mission blue. Thus, the butterfly's fate is closely tied to that of the three species of lupines as the plants provide food and shelter for the butterfly in its larval stage. The adult Mission blue drinks the nectar of a variety of flowers, many in the sunflower family, using its long proboscis which extends from the underside of its head.

The Little Sunflower Bläuling (Aricia agestis) is a butterfly (butterfly) from the family Bläulinge (Lycaenidae).

Endemic to specific ecosystems, eumedonia eumedon exhibits a remarkable adaptation in its larvae, which engage in a mutualistic association with ant species. These larvae secret a sweet substance that attracts ants, which in return provide protection against predators. The adult form is known for its striking wing patterns that serve as a visual deterrent to potential threats and plays a role in intraspecific communication during the breeding season.

In specimens [ of astrarche ] from the Canaries the red macular band of the upperside is occasionally quite uncommonly broad and of even width, so that it forms a regular band, only transected by the black veins; this is ab. cramera Eschsch. (= canariensis Black.) (80 a). I also caught very extreme specimens of this form on the slopes of the Aures Mts. in Algeria, although only singly; on the other hand I met on the Canaries with specimens of astrarche which certainly did not belong to cramera, but rather to calida.