Gardening Tips: August 20, 2013

Wasps, Yellow Jackets and Hornets
Every year I write pretty much this exact same column in which I encourage everyone to be careful to inspect the lawn for the presence of ground nesting yellow jackets, before mowing. Every year I ignore this good advice myself and I get stung! This is the time of the year when the populations of stinging insects such as wasps, yellow jackets as well as other hornets are at their maximum. Only a few of these survive our winter but they begin building their numbers in May and June. By mid August their nests are very large and it seems that their dispositions are at their worst. It is almost as if they know that most will perish in a couple of months.
Technically, most wasps are considered beneficial since they kill and feed on other pest insects. Honeybees can also inflict a painful sting but they rarely sting unless seriously provoked, or if their hive is threatened. Nevertheless if you are fond of walking barefoot on your lawn, beware of stepping on flowering clover or wild thyme that honeybees may be working. Honeybees give their life when they sting since their stinger is actually attached to their internal organs and it kills them to inflict a single sting. Yellow jackets and hornets can sting repeatedly which makes them far more dangerous.
For most people the reaction to a sting is relatively minor, resulting in pain and some swelling that goes away in a few hours. For others the reaction can be life threatening. If you should happen to get stung and you develop an allergic reaction in an area other then where you were stung, you need to get medical attention in a hurry.
For example, if you develop itchy hives or shortness of breath or swelling around your throat you need to get to an emergency room as soon as possible. A localized swelling reaction, even if it seems severe is not as serious as a reaction elsewhere on your body. If you get stung on your hand or wrist you should immediately remove any rings, bracelets or watches since the swelling might cut off circulation. Your doctor can prescribe a “kit” that contains medicine to be used in an emergency situation if you are seriously allergic to these types of stings. I always carry some Benadryl capsules with me when I hike in the woods in the late summer or early fall.

Perform inspections
Before you mow the lawn again or work in an attic or shed, take some time to carefully observe the area you will be working in for the presence of hornets or their nests. Inspect the lawn for signs of yellow jackets flying to and from a small hole in the ground. Ground nesting yellow jackets are also common in forested areas. Black bears and skunks are seemingly immune to the venom and often they will dig up these nests to eat the larvae. Beware of freshly dug holes in the lawn or garden as there may still be some angry hornets guarding the entrance.
Also look for the off white or gray colored, paper like nests in sheds, under porches, decks etc. Mud wasps make their nest from mud and are often found in sheds and garages. Be very careful opening the doors of cars that have been sitting for awhile. Even your garden tractor may have a hidden nest of hornets in it somewhere. If you should happen to discover a nest in a dangerous place you should plan to kill the hornets after dark on a cool evening. If you have propane gas tanks in your yard, do your delivery person a favor by getting rid of the nests that are often found under the lids of the tanks.
Purchase an aerosol can of wasp and hornet killer or better yet, purchase two or three cans. Do not spray until after dark on a cool evening when all the insects are in the nest and they are sluggish. Spraying the nest during the day will not kill all the foraging insects and they will build a new nest quickly. Carefully locate the nest and make certain you can see it at night with a flashlight. Spray directly into the opening hole or soak the entire nest with the insecticide. Use at least half the can of spray to be sure you have thoroughly saturated the nest. If no insect activity is noticed the next day you can be pretty sure that you have killed them all.
Normally I do not recommend the indiscriminate killing of insects, even wasps and hornets, but in some situations, they represent a serious threat to human health and need to be eradicated.