Extension news
By Roger Larson | 13th September 2008
Our Peoria County Master Gardeners, through the Helpline, have been inundated with questions concerning ladybugs. David Robson, Extension Horticulture Educator, provides some thoughts concerning that “mixed blessing.”
“Ladybugs are important predators of aphids and other insects. If you buy these insects to put out in your yard or garden, they must be handled properly so that you receive the full benefit from them.
Ladybugs, or more properly lady beetles, are roundish insects that are usually less than 1/4 inch long. Most of us are familiar with the convergent lady beetle, colored orangish-red with several black spots. Lady beetles may also be brown, yellow, red, pink, orange or tan with or without black spots, or they may be black with or without red spots.
Lady beetle larvae hatch from yellowish-orange eggs laid in a cluster. The larvae are usually elongated, are black and orange, and have large jaws.
Garden seed companies and nurserymen frequently sell convergent lady beetles after they are collected from large masses that overwinter together. They primarily feed on aphids, but will feed on any soft-bodied slow moving, tiny animal such as scale crawlers and mites.
Since lady beetles are already present in most areas, you can increase the effectiveness of lady beetles in your own yard if the insects have mulched areas in which to overwinter and insecticides are used sparingly. These practices will probably result in more lady beetles in your yard than if you purchased them.
If you do purchase lady beetles, make sure that there is suitable prey—such as aphids—on your plants when you receive them. If they arrive too early in the spring, store them in the refrigerator for a few weeks until they have something outside to eat.
Release the lady beetles about sundown at the base of aphid-infested plants. During the night, they will crawl around on your plants and perhaps find enough aphids to stay. Releasing them during the day frequently results in their flying away.
Place the beetles on damp ground that has mulch or fallen leaves on it. If the soil is dry, water it before releasing the insects. The damp mulch provides a humid hiding place for them.
Handle the lady beetles carefully. The more they are disturbed, the more likely they are to fly away to your neighbor’s yard.”
If you have other questions, call the Peoria County Extension Office. The number is 309-685-3140 or:
www.extension.uiuc.edu/peoria.