-
- Articles
Index : Pests
-
-
- 4. Inspect Plants for Spring Insect Pests - Top
- In the spring when garden and landscape plants put forth their new growth is the time when plant-damaging insects are at their peak. Getting the jump on these pests is the most effective way to ward off any potential injury to plants.
The most common garden and landscape insect pests out at this time of year are mites, aphids and thrips. Mites are primarily pests of needled-evergreen plants such as Italian Cypress, Arbor Vitae, Juniper and Cedar. Besides needled-evergreens, Pyracantha are also commonly attacked by mites.
Because mites work from the ground up, the place to look for them is at the bottom of the plant. Dry, brown needles with a dusty appearance indicate the presence of mites. On Pyracantha leaves turn an unusual coppery color. To be sure mites are present, the easiest test is to hold a white sheet of paper under suspicious branches and tap them firmly against the paper. If small dust-like specks are seen crawling against the white background, mites are present.
The easiest way to control mites is to spray infested plant with a strong jet of water from a garden hose attachment. The spray will knock off a large percentage of these sucking pests and prevent further injury to the plant. Repeat water sprays on an as-needed basis.
Aphids are another common insect pest found on a variety of garden plants including all types of flowers and vegetables, roses, citrus, deciduous fruit trees. Most aphids are green or greenish yellow in color and can be seen without magnification. But some aphids, like the wooly aphid found on Arizona Ash are white or gray in color.
Regardless of the type, aphids feed almost exclusively on the soft, new growth of plants. Their sucking of plant fluids causes young leaves to twist and curl. In addition, aphids secrete a clear, sticky substance called honeydew. If walking through the garden, you see plant leaves coated with a clear varnish-like substance, that’s honeydew, and you’ve found a colony of aphids! To control them, as with mites, you can spray them off with water. One spray should do it, and don’t worry, once they’ve been knocked off the plant, they won’t crawl back.
Thrips are small, thread-like insects that damage a number of plants including citrus and roses. On citrus, thrip feeding causes leaves to be cupped and curled much like the damage caused by aphids. But in addition, the leaves of citrus appear to be streaked with silvery lines. On roses, damage from thrips appears on the flower petals. They too appear streaked and blemished. Although thrips don’t do any real damage to plants, many rose growers use systemic insecticides to prevent thrips from damaging rose petals.
Most damaging insects including aphids and thrips are attracted to the color yellow. So one of the best ways to monitor for these pests is to set out yellow sticky trap cards. If insects inter the area they will be attracted to and stick on the cards. Sticky cards can be purchased at many garden centers or you can make your own by coating yellow construction paper with corn syrup. By checking the traps daily, you can determine when insect pests make their first appearance in the garden and then use selected control measures.
Written by John Begeman, College of Agriculture and Life Sciences, the University of Arizona,
520-626-5161. - Updated: April 16, 2006
-
-
[e-Mail me
the Articles] - [Search
the Articles]
-
|
