Organic isn't only winning over the eco-chic set. It turns out that ladybugs (a.k.a. coccinellids) also have an affinity for the sustainable. 

Researchers from the University of Granada in Spain have discovered that friendly pest-chomping ladybugs prefer pesticide-free olive orchards to conventional ones, paving the way for them to be used as markers of organic crops. The scientists report in the journal Ecological Indicators that there were consistently more ladybugs in an organically cultivated orchard than in those that had been sprayed with insecticides. The finding suggests that ladybugs, which gobble petite pests such as crop-devouring aphids, may serve as an indicator species, which are animals or plants that give a quick measure of an ecosystem's health—like the proverbial canary in the mineshaft. "Ladybirds (ladybugs in North America) fulfill all the requirements for a useful bioindicator," the study authors write.

Deborah Letourneau, an environmental studies professor at the University of California at Santa Cruz says the study is both "timely and useful" because it used—and highlighted the value of—such a common insect.

She  says that ladybugs—a beetle family, of which there are actually thousands of  different species—could be a handy gauge of orchard health because they're so easy to spot (she spent nine years identifying wasp species for a similar study). That means, "they are much more practical as a tool for farmers and gardeners," she told ScientificAmerican.com. She cautions, however, that more research is needed to confirm the results.

Maybe ladybugs are a sign of more than good luck.

Image courtesy of Dan Zen via Flickr