Archive for Sunday, September 2, 2001

Outsiders feel the sting of nest pests

September 2, 2001


As hot summer days slowly give way to milder weather, many of us are starting to spend more time outdoors. Unfortunately, we find ourselves sharing the garden with some unwelcome visitors stinging insects common to Midwestern gardens.

Three particularly bad inhabitants are yellow jackets, hornets and cicada killer wasps. Here are some tips for handling a colony of these potentially deadly attackers.

Yellow jackets are small black and yellow wasps that usually build their nests underground, in rock walls or old hollow tree stumps anywhere protected from the elements.

These social creatures usually have one queen and up to several thousand workers in a single colony.

They are quite aggressive and can chase an invader several hundred yards before retreating home. They mainly feed on meat scraps, pollen and sugary substances such as nectar from flowers.

As the days get shorter and flowers are less plentiful, these scavengers start looking for a meal elsewhere mainly your picnic.

Be cautious about sealing trash cans and other potential food sources. Likewise, look twice before taking a sip from that soda pop can that has been sitting on the picnic table for a while. All of these are potential food sources for hungry yellow jackets.

Control of these creatures is not easy. The nest must be located and then destroyed.

Approach the nest at night with the light of a flashlight covered with red cellophane. Thoroughly saturate the area with a liquid insecticide and quickly cover the hole with a shovel of dirt. Repeat treatments may be needed.

Hornets are a slightly larger cousin of the yellow jacket. They prefer to construct nests above ground in trees and bushes, usually high enough not to be disturbed by us ground dwellers. But I have seen nests as low as 4 feet off the ground.

Hornets construct their nest of a papery-type material that they make using cellulose and saliva. Nests can be as small as a softball but gradually are built to be larger than a basketball.

With thousands of hornets per nest, they are quite aggressive and will defend the nest when provoked. Control of these creatures is less difficult.

If the nest is within 10 feet of the ground, use an aerosol spray labeled for use on wasps and other flying insects. Thoroughly saturate the hive in late evening or early morning hours.

If the nest is higher, little can be done and the nest should be left alone. If you do not disturb them, they will not attack you. The first hard frost will kill the hornets.

The final ominous pest is not really a pest but a nuisance. Cicada killer wasps are a rather large and threatening insect. Measuring up to 3 inches long, they seemingly are some beast from a sci-fi horror flick. But in the real world, they are quite harmless, although they dig quarter-size holes in the ground.

They are mostly black with a few yellow bands on their back end and reddish-orange wings. Cicada killer wasps get their name from the food they feed their young. The female digs the hole, then searches for a cicada. Once found, she carries it back to the hole and lays an egg on it. The emerging larvae will consume the cicada this fall.

Only the female wasps can sting. Male wasps do not have the equipment to do so. Even so, females are docile and it is difficult to get them to sting.

Control of these creatures is not usually needed. However, if you have them digging in flower beds or other exposed dirt areas, control is the same as for yellow jackets.

Bruce Chladny is horticulture agent at K-State Research and Extension-Douglas County. For more information, call him at 843-7058 from 8 a.m. to 5 p.m. weekdays.

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