Indian River County Extension Service
1028 20th Pl, Suite D
Vero Beach, FL 32960
23 January 2002
FOR RELEASE : January 27, 2002
Daniel F. Culbert, County Extension Director
BIG EYED BUG CAN BATTLE BAD BUGS
Some area residents are starting to be concerned about the loss of many of the chemical pesticides that have been traditionally used to "control" landscape insect pests. Property owners who have infestations of chinch bugs may want to consider the use of a beneficial insect known as the Big-eyed Bug. These good bugs may help manage insect pests, and can be used along with proper landscape management to produce Florida Friendly Yards.
On a recent visit to Gainesville, I had the chance to visit a "bug factory" that rears beneficial insects that are sold to commercial nurserymen. These bugs are also available to homeowners. Today’s column will tell you how they might be used in our Florida Yards. Information for today’s column comes from a University of Florida "Featured Creatures" Extension bulletin and from other entomologists from Texas and Arizona.
What is Biological Control?
Biological pest control can use natural enemies of insects to keep pest populations below levels where economic damage will occur. It is not used to eliminate pests, so some pest damage may be seen on protected plants. This is why some nursery growers don’t use biological control - their market demands perfection.
The purchase and release of beneficial insects may be used to augment existing beneficials, or can inundate an area depending upon the desired effect. There are three kinds of strategies used with beneficial insects:
Manipulative biological control makes use of beneficial organisms that are already present. Efforts are made to make conditions as favorable as possible for the good guys, and especially to avoid spraying pesticides that will harm them.
Augmentative biological control relies on releasing low numbers of natural enemies, especially when pest populations also are low, to achieve pest control within a few generations of the natural enemy’s life cycle.
Inundative biological control is when large numbers of natural enemies are released to quickly knock down a high pest population. Inundation strategies can be expensive and may upset natural balances that are found in a local environment.
Life of the Big-eyed Bug
Big-eyed Bugs are small insects that occur in many parts of the world. They are generally regarded as beneficial because they prey upon numerous kinds of insect and mite pests of turf, ornamental and agricultural crops. These predators are in the group of insects known as "true bugs", known as Hemiptera. They show gradual metamorphosis, and as adults have half-wings that form an X-like pattern across their back
The big-eyed bug adults and nymphs have oval bodies and broad heads. Their most distinguishing characteristic is their large, bulging eyes. They have relatively short antennae that are slightly enlarged at the tip. Big-eyed Bugs walk with a distinctive "waggle" and omit a fowl odor when handled. Adults are about 3/16th inch long and silver/gray in appearance. The nymphs look like small adults, but lack fully developed wings. "Hot dog" shaped eggs, white to tan with a distinctive red spot, are laid singly on leaves and stems of many crops. Immature stages (nymphs) resemble adults but do not have fully developed wings. Both the adults and nymphs feed by sucking juices from their prey through a "needle-like" beak.
Big-eyed Bugs are among those insects being researched for their value as predators. Reported among their prey are aphids, spider mites, whiteflies, small caterpillars, thrips and chinch bugs. On the negative side, however, they occasionally prey on other beneficial species. Entomologists have found nineteen species in the US, but Geocoris punctipes is the species common throughout Florida; its range spreads south and west from New Jersey to southern Indiana, Colorado, south to Texas, Arizona, California, and Mexico.
Because chinch bugs are sometimes confused with Big-eyed Bugs, it is important to have turf specialists to distinguish between these insects. Misidentification could result in a chinch bug spray directed against the beneficial bug, resulting in needless loss of money and beneficial insects. Our office has several detailed descriptions and photographs that should be consulted.
The Big-eyed Bug’s average development time from egg to adult is 30 days at 80E F. Adults overwinter and lay eggs singly on leaves or stems and will hatch in approximately one week. Nymphs develop through 5 stages before becoming winged adults. Nymphs are very hungry: one scientist found that nymphs consumed an average of 47 mites, and adults an average of 83 "red spider" mites on cotton plants per day. The Big-eyed Bugs will live and reproduce for three to six months - a female can lay up to 300 eggs during her adult life span.
Using Big-eyed Bugs
Organic farmers and some nursery growers have embraced the use of beneficial insects as a way to manage their pests. The release of beneficials may also be a solution for some pest problems facing home gardeners. The Environmental Protection Agency has recently taken action to remove several products from the home market. As a result, the widely used organophosphate pesticides Dursban™ and Diazinon™ will be unavailable to consumers after 2004. Beneficials may be part of the solution for filling the huge gap that will be created by this loss.
Supplying beneficials in immature, wingless form is aimed at keeping the beneficials in the release area for a longer time. The number of beneficial insects needed depends on the type of pest, the pest population, and the environment. Greenhouse experiments have shown that one hundred Big-eyed Bug nymphs can consume over 1,800 aphids in seven days. Due to the small size and secretive nature of this beneficial, it is difficult to quantify the number of prey needed to manage pest populations in the field. As a basic recommendation, one supplier suggests one beneficial insect per square foot of nursery plant growing area can be used. In a landscape setting, larger populations will probably be needed to make a greater impact. When using these predatory It would be helpful to do periodic soap-tests on turfgrass to find out how many pests and predators are present.
Beneficials will move to the area with pests because the pests are food. After the pests are consumed in an area, the predators will continue to search for more pests to eat, and may move from the release site. Big-eyed Bugs are very fast moving insects, and if alarmed, they will hide from movement. After releasing beneficial insects, it may take 7-10 days to see a decline in a pest population. It takes time for the beneficial insects to catch up with the pests. During cold weather, beneficial insects hibernate in leaf litter as adults. If a warm day occurs, the insects will come out to forage for food, and can return to the hibernation state at any time.
Where to get Big-eyed bugs
Information available to our office indicates there are currently two vendors that are raising and selling this predatory insect. Biofac Crop Care, Inc. in Mathis, Texas is listed in a national directory of biological pest control vendors. The other source is the "bug factory" in Gainesville that was on our recent tour; Entomos, that currently sells a "unit" of 100 big-eyed bug nymphs for just under $15.00. Contact us if you want addresses, phone numbers or e-mail for these suppliers.
Gardenfest at Riverside Park
I’ve been asked by the Garden Club of Indian River County to assist in getting their new community event off the ground. Gardenfest comes to Vero Beach’s Riverside Park next weekend, from 10 am to 5 pm on Saturday and 10 am to 4 pm on Sunday. Besides numerous invited vendors and educational exhibits, there will be several presentations made throughout the weekend. I’m scheduled to talk about the Florida Nurserymen & Growers Association Plants of the Year 2002 on Sunday morning. Our Master Gardeners will be there in full force. I’ve also arranged for Entomos to supply us with some Big-eyed Bugs which we hope to release at Gardenfest. I hope to see you there.
If you need additional information on the big-eyed bugs, visit our Master Gardeners, or call or stop by our office. For those with other questions about Florida Yards, our office holds Master Gardener Clinic hours at the Extension office (1028 20th Place, Suite D, Vero Beach) every weekday morning and most afternoons, Wednesday morning at Sebastian City Hall, and the first Saturday of the month at the Environmental Learning Center. Our phone number is 770-5030, and you can e-mail us at Indian@mail.ifas.ufl.edu .