Excerpts from Jim Conrad's
from the March 30, 2009 Newsletter, issued from near Natchez, Mississippi:
ROVING TIGER BEETLES
On warm, sunny days down in the bayou you're likely to see a very distinctive, memorable beetle. About half an inch long, what's striking is its shining, metallic green color and the way it zooms out of nowhere, lands on an unvegetated sandbar, then rushes around on long legs looking for prey. Its movements are so fast and aggressive that it gives the impression of being a maniacal little hunting machine. One is shown above.
It seems that such a distinctive looking creature would be easy to identify but I'm only fairly certain that it's the Six-spotted Tiger Beetle, CICINDELA SEXGUTTATA. You can see that my individual has no spots, and that's why I'm uncertain, though I read that unspotted ones have been seen. Nearly 2,000 species of tiger beetles are recognized worldwide, with 120 in North America, so ours might be another species.
Whatever the species, beetles of the genus Cicindela are known as tiger beetles, and tiger beetles are famous for their hunting prowess. They eat other beetles, flies, caterpillars, ants, grasshoppers, spiders and other invertebrates, but they're also fed upon by spiders, robber flies, dragonflies, toads, lizards, birds, and more. In other words, they're fully engaged members of the community.
As a group, tiger beetle anatomy is distinguished by the slender area between the head and wings -- the "narrow pronotum."