This spring, I was an invited speaker at Epcot’s International Flower and Garden Festival in Orlando. My topic was “Good Bugs – Bad Bugs.” I provided 6 presentations to more than 300 attendees representing at least half the states in the United States and several other countries. All audiences could identify the adult lady beetle as a beneficial insect (good bug). Even children attending could quickly and correctly identify the ladybeetle from a picture. But few could correctly identify the larva stage for the ladybeetle. When shown a picture of an earwig, all audiences failed to identify this insect as beneficial. And only one audience member out of the several hundred participants correctly identified a beneficial stinkbug from a photo. This person was a Master Gardener from South Florida.
I started my presentations by asking the audiences the question, “What percent of insects in Florida are potential pests of our lawns, landscapes and gardens?” The answers varied from 30% to all “bugs” in Florida are bad, or 100%. The correct answer based on UF/IFAS Entomologists is less than 1% of all insect species in Florida are plant pests. That means that the vast majority of insects in Florida are either beneficial or are of no consequence to our plants.
We are blessed with a wealth of beneficial insects. You’d be wise to take time to learn how to recognize some of these beneficial insects. Let’s consider a few of our common beneficial insects.
It’s important to learn to recognize the adult and immature stages of these beneficial insects. For example, ladybeetles have larvae that look nothing like the adults. Some ladybeetle larvae look like small orange and black alligators. Others may resemble mealy bugs. Many gardeners that would never kill adult ladybeetles mistake ladybeetle larvae as pests and kill them with pesticides.
Earwigs are considered beneficial because they are predaceous upon many pest insects. A common earwig species in our area eats chinch bugs, immature mole crickets and sod webworms. A single earwig has consumed fifty chinch bugs during a single day in laboratory experiments. Chinch bugs are damaging to St. Augustinegrass.
Not all stinkbug species are harmful. Many are predaceous. A common predatory species is midnight blue and orange in color. Many pest stinkbugs that feed on plants have rounded “shoulders” or thoraxes, while beneficial species can be identified by individual spines projecting from their “shoulders.” They feed on many pests, especially caterpillars.
The following online publications will help you learn to recognize many of our beneficial insects: http://edis.ifas.ufl.edu/in002, http://edis.ifas.ufl.edu/in003, http://edis.ifas.ufl.edu/in012 and http://edis.ifas.ufl.edu/in013
Larry Williams, UF/IFAS Extension Agent, Okaloosa County