The genus Chilades includes one of the smallest known butterfly species on Earth. Chilades lajus is a very widespread and common species, found from India and entire South East Asia. This is a common species present in NEERI campus. Lime blue is mainly associated with dry forest but can also be seen in Citrus orchards and Acacia scrubs in cities. It is very active but flies close to the ground and settles quite often. It has fluttering flight usually around food plants. Lime blue is more common in drier, open habitats. Can be seen around flowers, bird droppings and damp patches. It is on wing throughout the year.

Wing span of lime blue is 26-30 mm. Male shows a seasonal variation and in the dry season form having a darker brown on the underside of the hind wing. It is violet blue on the upper side marked with tornal spot. Female is light blue at the basal area of the wings and has broad bands with a series of tornal spots. The underside is heavily speckled and has black spots on the hind wing. Caterpillar of lime blue is considered a minor pest of Citrus in tropical Asia. Control is usually not required.