Square-spotted blue

''Euphilotes battoides'', the square-spotted blue or buckwheat blue, is a species of butterfly of the family Lycaenidae. It is found in western North America from Washington south to Baja California Norte and then west to southern Colorado and New Mexico.

The wingspan is 16–17 mm. The upperside of the females is brown often with an orange band on the outer edge of the hindwings. Males are blue with dark borders and sometimes an orange band on the outer edge of the hindwings. The underside is off white to grey with black spots. Adults are on wing from mid April to August in one generation per year. They feed on the flower nectar of various plants, but mostly ''Eriogonum'' species.

The larvae feed on the flowers and fruits of ''Eriogonum'' species. Subspecies ''battoides'' has been recorded on ''Eriogonum lobbii'' var. ''lobbii'', ''Eriogonum incanum'' and ''Eriogonum polypodum'', while subspecies ''glaucon'' feeds on ''Eriogonum umbellatum'', ''Eriogonum ovalifolium'' var. ''nivale'', ''Eriogonum heracleoides'', ''Eriogonum sphaerocephalum'' var. ''halimioides'' and ''Eriogonum flavum'' var. ''piperi'' and subspecies ''comstocki'' feeds on ''Eriogonum umbellatum''. Subspecies ''allyni'' has been recorded feeding on ''Eriogonum parvifolium'' var. ''parvifolium'', records of ''Eriogonum cinereum'' and ''Eriogonum fasciculatum'' var. ''fasciculatum'' are in error, allyni is restricted to E. Parvifolium. The larvae are tended by ants. The species overwinters, in chrysalis, in sand or leaf litter.