Not too long ago (maybe a decade or more) one of the staples of the summer was seeing fireflies light up the night sky. In more recent years it seems they have all but disappeared.

Photo: Bart Drees, Extension Entomology, Texas A&M University Scientific name: (Coleoptera: Lampyridae) Facts: Fireflies are well known for their nighttime light displays. The light-producing organs of these soft-bodied beetles are located in the yellowish-green areas on the undersurface of the abdomen. The production of light (bioluminescence) is found in relatively few other insect families.

Fireflies are still around, but they are not nearly as numerous. Some San Antonians are still lucky enough to spot a few around dusk.

There are probably multiple reasons why the fireflies have gone away, but I believe one reason probably makes a greater impact: habitat destruction. Fireflies, which are actually beetles, live in pretty densely wooded areas. Around dusk they emerge from their hiding places to start their courtship dances. They use a chemical in their abdomens called cantharadin to fluoresce in order to attract mates. Both males and females do this. What we enjoy watching at night are their dating rituals. Fireflies emerge from wooded areas into clearings so that trees and other objects don't obstruct their view of the opposite sex.

"Lightning Bug" Larva Photo by Gerald Lenhard, www.forestryimages.org

Every year, more and more of those types of habitats are being used up to build neighborhoods, businesses, and strip centers. In addition, our homes have smaller yards and fewer trees-there are just no good places for fireflies to live anymore.

You can still find them wherever there are many trees and a generally clear area next to the trees--Think: fields next to woods, an easement, and areas cleared for telephone poles, new roads, railroads, or subdivisions.

I am sure there are multiple other reasons why fireflies seem more scarce, and my theory has not been studied or tested...just an idea!

IPM Program Specialist and Entomologist, Molly Keck
mekeck@ag.tamu.edu
3355 Cherry Ridge, Suite 212
San Antonio, Texas 78230
210/467-6575