EPOW - Ecology Picture of the Week

The Silver-lined Jewel That Flies

Glorious Jewel Scarab (Chrysina gloriosa), Family Scarabaeidae
Oracle, Arizona USA

Explanation:  Wandering into our rustic ranch get-away in the mountains north of Tucson, Arizona, one summer morning was this spectacular scarab beetle ... aptly named the glorious jewel scarab, also called the silver-striped jewel scarab.

Glorious jewel scarabs are found in southwest and south-central U.S., south into Mexico.  They look like brilliant signals but actually blend into the vegetation.  Adults reportedly feed on juniper foliage, and larvae are found in decaying sycamore logs.   

The adults (shown here) are active during summer and may be attracted to lights at night, which could be how this specimen found our mountain hideaway.  

A recent study has found that jewel scarab beetles can find each other with polarized light that creates specific patterns on the elytra (the colorful 'body' that, in beetles, is actually two shells that hinge open to reveal the wings beneath).  The advantage of such a skill is to be able to hide from predators, who cannot see in polarized light, but still detect each other.   

Jewel beetles are so spectacular in appearance because of the iridescent, reflective nature of their exoskeleton.