Of all insect species, the honey bee is perhaps the most beneficial. There is, of course, honey: about 200 million pounds of it is produced commercially each year. But the honey bee makes its greatest contribution by pollinating plants. More than one half of all fruit and vegetable crops are pollinated by honey bees. Wasps contribute by preying on many pest insects harmful to crops. Without bees and wasps, our menu would be very limited.
Unfortunately, bees and wasps can be a threat to human health. Each year, 50 to 100 people die from bee and wasp stings. Most die from an allergic reaction to venom within one hour of the sting. About 1 percent of the population is allergic to bee and wasp venom. Those allergic to stings should carry emergency epinephrine injection kits as directed by their doctors.
Though related, bees and wasps differ in important ways. Most wasps have a narrow “waistline” where the front portion of the abdomen tapers to become a small tube as it attaches to the middle body section, the thorax. Bees do not have this narrowing of the abdomen. Another difference is that bees feed nectar and pollen to their young (larvae), while wasps feed their larvae insects and spiders. Yellowjackets and hornets also scavenge food including fruit, sweets, meats and carrion.
One thing bees and wasps have in common is that some species are solitary and others are social. A solitary bee or wasp lives alone, making its own nest and raising its own larvae. Individuals of social species live together in colonies consisting of many “workers” and one or more “queens.” The workers specialize in different tasks, and cooperate to raise the queen’s offspring. These species should be considered a greater threat to humans than solitary species. This is because social species, such as honey bees and yellowjackets, will defend an entire colony, and have more individuals available to do so. Solitary species, such as mud dauber wasps, defend their nest alone.
Honey Bee (Apis mellifera)
Bumble Bee (Bombus spp.)
Carpenter Bee (Xylocopa virginica)
Paper Wasps (Polistes spp.)
Yellowjackets (Vespula spp., Paravespula spp.)
Hornets (Dolichovespula maculata and Vespa crabro)
Mud Daubers (Sceliphron caementarium, Chalybion californicum, Tropoxylon spp.)
Cicada Killer (Sphecius speciosus)
MANAGING BEES and WASPS
The most important element of wasp and bee control is to destroy the nest. Aerosol “wasp and hornet” sprays can be used to knock down bees/wasps around the nest. Small amounts of pesticides (dust and wettable powder formulations work well) applied into the nests of carpenter bees and cicada killers provide good control. Nests of mud daubers also can be treated this way or by simply scraping them off structures. To prevent reinfestation, finishes (paint, etc.) can be applied to unfinished wood to discourage carpenter bees.
In some cases, attempting to destroy a nest becomes a greater health risk than simply tolerating and avoiding it. But nests, especially those of social species, should be destroyed if they are close enough to humans to pose a stinging threat. The nests of honey bees, bumble bees, yellowjackets and hornets should always be approached with caution, preferably at night when most of the workers are present but reluctant to fly. Try not to carry a light, as wasps and bees may fly toward it. Instead, set the light aside or cover it with red cellophane (insects cannot see red light). If there is direct access to the nest, a fast-acting dust or wettable powder formulation can be applied. If possible, inject the material into the nest. If you must approach these nests during daytime, a quick knockdown aerosol can be used to keep the bees/wasps at bay, while you treat the nest as above. Heavy clothing or a “bee suit” can be worn for added protection.
Sometimes, yellowjacket and honey bee nests occur in voids such as vents, attics, crawlspaces or hollow walls. Destroying nests in these locations can be difficult, often requiring the services of pest management professionals. Honey bee nests contain honey that must be removed after the bees are eliminated because it will rot and attract secondary pests. Also, be mindful that nests may be located several feet away from the point at which the bees/wasps are entering the structure. Simply applying pesticides into the entrance holes may not be sufficient. It may be necessary to drill into the structure to enable injection of pesticides directly into the nest. Entrance holes should never be plugged, even after treatment, because the bees/wasps will look for other ways to get out of the nest and have been known to chew their way into living quarters, endangering persons inside. Also, use extreme caution when performing bee/wasp control from a ladder.Another special case occurs when large numbers of yellowjackets forage in public areas such as parks, schools and zoos. Attracted to human food, especially meats and sweet liquids, wherever it is being prepared, eaten or discarded, yellowjackets pose an increased threat to humans. Control is often difficult. When located in wooded areas, the nests can be difficult if not impossible to find and treat. Yellowjacket baits and traps can kill large numbers, but there can be a lot more where they came from and the problem may continue. Other types of pesticide applications for control of yellowjackets in outdoor recreation areas are rarely effective. Consequently, management of yellowjackets should focus on prevention, such as keeping food enclosed. Tight-fitting lids should be kept on outdoor trash containers and they should be moved away from people. In the end, not eating in infested outdoor areas may be the only sure way to avoid being stung.
NOTE: When pesticides are used, it is the applicators legal responsibility to read and follow directions on the product label. Not following label directions, even if they conflict with information provided herein, is a violation of federal law.
For more information, contact the Illinois Department of Public Health, Division of Environmental Health, 525 W. Jefferson St., Springfield, IL 62761, 217-782-5830, TTY (hearing-impaired use only) 800-547-0466.
of Public Health
535 West Jefferson Street
Springfield, Illinois 62761
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