Plants and Bugs That Love Them
Presented by Clair Stuart

Most bugs have favorite hosts. Learning which plants attract what bugs helps in: bug identification and management; anticipating life cycles and potential damage; and deciding whether the plant is worth growing given the bugs likely to be attracted. Examples are azaleas which attract aphids and lace bugs, particularly if sited in full sun; hollies which attract scale, leaf miner and mealybugs; columbine and black locust which are favorites of the leaf miner; and eggplant, favorite of flea beetles.

Many bugs are good bugs because they help to control the bad bugs. Examples of the good bugs or beneficials include: Lady Bugs or Beetles, Soldier Beetles, Praying Mantis, Lacewings, Hover Flies, Parasitic Wasps and Predatory Mites. Other critters that help manage the bug problem are spiders, birds, frogs, snakes and toads. Some insects are neutral--the plants live with them. For example, most gall-forming insects and box elder bugs, that drive people crazy, but do little harm to trees.

In managing the bug population, frequent scouting is necessary to determine which side is winning the war -- the good bugs or the bad bugs. The challenge is to first correctly identify the bug ,then anticipate its life cycle and determine appropriate intervention, if any.

All bugs are either chewers or suckers. The chewers cause obvious damage by demolishing the plant. Frequently the bug will move on to the next developmental phase and the plant will recover. The suckers' damage is less obvious. Look for curled or discolored leaves or tiny brown spots that do not go all the way through the leaf. If there are random abnormalities in the way the plant looks, it may be the result of bugs which are sucking out the juices of the plant and inserting a toxin which is causing the damage. By the time the symptoms are recognizable, considerable damage may already be done or the insect may no longer be present.

In determining if the bug is good or bad, according to Claire Stuart, if it hops (including grasshoppers, planthoppers, leafhoppers, psyllids) chances are good that it is a bad bug, as are aphids, thrips, whiteflies, and mealybugs. Consider all caterpillars bad unless they are larvae of butterflies feeding on weeds or on things planted for them in butterfly gardens. The bad bugs are those which are capable of doing lasting damage if left unchecked. Look for evidence of their presence. If you see no insects, look on the undersides of the leaves and at night.

In managing their damage, catch them early and start with the least toxic, most targeted intervention such as removing the bug (such as bagworms); cutting back the plant (such as columbines) or using spot treatments. In treating, try soap solutions for soft sucking insects (aphids, thrips and mites) and horticultural oils on woody plants which are attracting insects with shell-like coatings, such as scale. There are also biological controls that rely on environmentally safe bacteria that attack the pest you are trying to control. An example is Bacillus thuringensis (Bt) which is used for caterpillars.

If these strategies are not working, consider the limited use of chemicals that are specifically designed for your plant and the insect infestation that you have identified. Use systemic or contact chemicals for suckers and stomach poisons for chewers. When selecting the product, pay particular attention to its likely impact on the water table, nearby ponds, pets, beneficials, birds and other wildlife. Apply the recommended dose at the frequency suggested and avoid repeated use since insects are capable of
mutating and developing immunity to repeated use while the beneficials are likely to be killed creating a bigger problem than you had in the first place. AVOID CONTACT POISONS DURING POLLINATION.

Since healthy plants are less likely to be attacked by bad bugs, use good gardening practices which encourage their vigor. Factors which are important are: soil which has the composition and nutrients needed, pH levels that are appropriate for the plant, adequate water and good air circulation.

Bug Identification Books--Claire Stuart's Favorites.

Butterflies of West Virginia and Their Caterpillars by Thomas Allen University of Pittsburgh Press.

Eastern Forest Insects by the U.S. Department of Agriculture
Peterson's First Guide to Caterpillars by Amy Bartlett Wright
Butterflies and Moths, A Golden Guide by Robert Mitchell & Herbert Zim.
Insects That Feed on Trees & Shrubs by Warren Johnson & Howard Lyon
Bugs and Beetles by Ken Preston-Mafham, Chartwell Books
 
 
 

© 2000-2006, Gardeners' Exchange Group P.O. Box 3415 Shepherdstown, WV 25443-3415 Comments or suggestions? Send them to Please review our Privacy Policy.

You are visitor number  2200  to this page since 6 April 2001.