E. isola life history
Reakirt's Blue (Echinargus isola) Life History

12-4-11, adult female ovipositing

12-4-11, egg among buds

12-6-11, egg more visible as buds grow

12/11/11, day-old caterpillar




12-25-11, now in last instar

12-27-11, mature caterpillar

12-31-11, pupa

1-16-12, almost ready to emerge

Fresh Reakirt's Blue ventral, 1-17-12

Fresh Reakirt's Blue dorsal, 1-17-12

I have typically found Reakirt's Blue caterpillars on Mesquite flowers. However, on this occasion I witnessed a female depositing an egg on Powderpuff flowers (Calliandra emarginata). The egg eclosed after 7 days. Typically, Blues caterpillars emerge more quickly, but this was during December and cooler weather is probably the reason for the longer incubation period.

The caterpillar took 18 days to mature. The first instar was a pale, off-white color. By the time it reached the final instar, it had absorbed the pigments of the Calliandra flowers and gained beautiful pink markings. In a similar fashion, the caterpillars I have found on mesquite blossoms usually have yellow markings that enable them to blend in with those flowers.

Inset: ants tend to a caterpillar
eating mesquite flowers.


The caterpillar of the study became prepupal on the 28th and the pupa was formed the following day. The adult emerged on January 17, 2012.

Reakirt's Blue Page