The last picnics of summer are often beset with pests. Traditionally, ants are the most talked about, but flies, mosquitoes and others become uninvited guests. Perhaps none are as feared as the bees and wasps. Although it makes little difference which is attacking if you are in fear of being stung, each kind has significant distinguishing characteristics. However, if they fly and buzz, they strike terror wherever they visit.
There are hundreds of different species of bees and wasps, and most perform valuable functions. Without them, we would have almost no fruits and few vegetables. Many of the seeds we use would not exist because they require insects to transfer pollen. In addition, they also feed on harmful insects. In spite of their valuable service, there are a few kinds that can cause problems.Wasps, hornets, mud daubers and yellow jackets are all common in our area. They all sting, and because their stingers are not barbed, they can inflict multiple stings. About four people per thousand are hypersensitive to the venom and should take special precautions to avoid being stung. Wasps and hornets all die in cold temperatures in the fall, although some enter homes to overwinter.
Paper wasps are about 1 inch long with narrow waists, long legs and abdomens with yellow markings. Their paperlike nests are attached to eaves, rafters, siding or other hiding places. Cells in the nests all have six sides. The larvae hatch inside these and develop into adults.
Bald-faced hornets are 3/4-inch long with black and white markings. They form large, pear-shaped gray nests of paperlike material. Their nests can be as large as a basketball or even larger and the insects enter from the bottom. The insides of the nests are arranged in layers where the hornets light for the night. As many as 3,000 insects may inhabit one nest, so use extreme caution to avoid these.
Mud daubers or pipe organ mud daubers form small mud tunnels that resemble organ pipes for nests. These are under roof overhangs, eaves and in other locations. The wasps are not aggressive and despite their formidable appearance rarely require control. They are shiny and black with slender, elongated bodies. Mud daubers are solitary, so queens care for nests and young. They prey on spiders, which they paralyze with their venom then drag into their nests. They implant eggs into a spider's body, which the larvae use for food after the eggs hatch.
Yellow jackets are a half-inch long with black and yellow bands covering their bodies. Unlike honey bees, they have no hair on their bodies. They have well-developed mouth parts for catching and chewing insects and sucking nectar. These are most likely of all to come into conflict with humans. They may nest in decaying trees, in shrubs, in cavities in the soil, in walls of homes or in and around wood piles. These colonies can go from a single queen to over 5,000 insects by fall.
In the spring all these insects have beneficial functions as they pollinate plants. They continue to be beneficial as they feed on corn ear worms, army worms and other pests. Hornets also feed on housefly and blowfly larvae and other harmful caterpillars.
Unfortunately, as summer goes on, they develop an increasing need for protein in their diet. Since they can't get enough from the insects they catch, they become meat eaters. They also feed on rotting fruit and on sweet liquids such as soda pop.
To avoid problems and stings, be careful cutting weeds, pruning trees or otherwise working in the garden. Do not wear perfume or sun tan oil or use perfumed soaps and shampoos. Avoid shiny jewelry and brightly colored flowered clothing or florescent colors. Wear long sleeves and cover as much of your skin as possible. Avoid confrontation with the insects and, if threatened, avoid sudden movements. Don't kill individual insects as they give off a pheromone that excites others in the area that may come and sting you. Cover garbage cans, pick up rotting fruit and keep areas free from debris.
Chemical control should be used only as a last resort. Nests can be destroyed using flying wasp and hornet sprays that literally paralyze the insect in flight. This helps protect you from being stung. Most garden sprays may take as long as 30 minutes to kill the pest, so avoid using them if the insects are threatening. If nests are a severe hazard destroy them at night. Use a red light to approach the nest, as they cannot see this color. Repeat treatments may be needed as the eggs continue to hatch. Baits containing Sevin mixed with tuna or fish-based cat food are also effective.
Common sense, avoidance, sanitation and traps should prevent most problems with these insects. These insects keep worms out of your corn, off your tomatoes and perform many other beneficial functions. Preserve them to help you in your quest for a pest-free garden.
- USU/UTAH BOTANICAL GARDENS OPEN HOUSE: Saturday, Sept. 2, at 1817 N. Main, Farmington, from 9 a.m. to 3 p.m. No admission charge.
Lectures and demonstrations:
9-3 p.m. "Solar Leaf Printing" workshop for children and adults, LeRoy Behling.
10:30-11:30 a.m. "Saving the Harvest, Food Preservation Tips," JoAnn Mathis Ross, USU Extension home economist.
12-1 p.m. "Basic Home Landscaping, Where Do I Begin?" Anne Spranger, MLA, Dave Anderson, MLA, Utah Botanical Gardens landscape architects.
1:30-2:30 p.m. "Creating Herbal Vinegars & Jellies," Evelyn Jensen, USU Extension master gardener.
Guided garden tours: Garden volunteers will conduct tours of the gardens every hour from 9:30-2:30 p.m.
Information and plant diagnostics: USU horticulturists and master gardeners will help solve plant problems. Garden fact sheets and food preservation bulletins will be available.
Share your garden produce: Bring your extra garden produce and canned goods, which will be shared with those in need.
Dried flower craft sale: Master gardeners have collected, dried and prepared flowers and herbs for sale in Garden Boutique.
Iris & Daylily sale: Bareroot iris and daylilies from the gardens will be for sale.
- THE AFRICAN VIOLET SOCIETY OF UTAH will meet on Sept. 7 and Oct. 4 at 7 p.m. at the Garden Clubs Center, 1602 E. 2100 South. Guests are welcome.