-
- Articles
Index : Pests
-
-
- 24. Pest Problems Begin Early - Top
- Our early warm weather has brought with it an abundance of pesky insects. Fortunately, most cause little damage to garden and landscape plants. A few, however, do require some control measures.
Probably the most common insects out and about the garden these days are aphids. They are small, soft bodied bugs that can be found on the new growth of most plants. They come in a range of colors including; brown, purple, yellow, black, but most often green. Although small, they can be seen without magnification. Their favorites are roses, hibiscus, and most herbaceous garden plants.
Because aphids are sucking insects they secrete a sticky substance called ‘honeydew'. This substance coats nearby leaves and stems making them appear shiny as if lacquered. If you see the honeydew, look closely for aphids.
Aphids seldom cause harm to plants. They are more of an unsightly nuisance. However, on young garden plants they can be very harmful. The honeydew secretions can cause a mess on cars, walks, and patios located under infested trees.
Aphids can usually be controlled by spraying with a strong jet of water from the garden hose to knock them off leaves and stems. Make sure to spray all around, both over and under the leaves. Aphids knocked off plants will not crawl back. Soap sprays can also be used for hard to control aphid populations, such as those on oak. Make your own soap spray by mixing 1 tablespoon of liquid dish washing detergent in one gallon of water. Soap sprays are relatively harmless to beneficial insects.
With warm, dry weather comes another common landscape pest; the spider mite. Spider mites are small, almost microscopic, insect-like pests. They are not true insects but rather aracnids related to true spiders and scorpions. Like aphids, they suck out plant fluids. Unlike aphids, spider mites are found more commonly on older growth and nearer the ground. As they continue to feed, they work their way up farther into the plant. Evergreens, such as juniper and Italian cypress are favorite spider mite meals as are roses, pyracantha, oleander, and flowers both annual and perennial.
Plants infested with spider mites will display a characteristic brown cast to needles or leaves. Close examination will reveal tiny stippled spots of yellow or brown. To find the mites themselves, simply shake the foliage in question over a white sheet of paper. If you find small dust-like specks crawling about, your plant has mites. Like aphids, they can be sprayed off with a strong jet of water or a mixture of soap and water to wash them off. Repeat the water spray every 10 days until mites have been brought under control.
Beneficial insects are also out-and-about in the spring garden. Lady bugs, parasitic wasps, assassin bugs, lacewings and others are out and about, so protect them. Only spray with garden insecticides when pests are causing significant damage to plants and other non-chemical controls have failed. Water and soap sprays will not harm beneficial insects. They will, however, control most common garden and landscape pests. Remember, even organic insecticides derived from plant extracts, such as pyrethrin and rotenone, can kill our beneficial garden insects.
The topic for this weeks garden demonstration will be Choosing and Planting Desert Trees. It will be presented on Wednesday at 9:00 a.m. at the Pima County Extension Center, at 1:00 p.m. at the Wilmot Library, and on Thursday at 2:00 p.m. at Marana Planning Services on the Northeast corner of Orange Grove and Thornydale. Answers to gardening questions may be obtained by phoning 626-5161 in Tucson or 648-0808 in Green Valley.
Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with U.S. Department of Agriculture, James A. Christenson, Director, Cooperative Extension, College of Agriculture and Life Sciences, the University of Arizona.
The University of Arizona college of Agriculture and Life Sciences is an Equal Opportunity employer authorized to provide research, educational information and other services only to individuals and institutions that function without regard to sex, race, religion, color, national origin, age, Vietnam Era Veteran's status, or disability.
- Updated: April 20, 2001
-
-
[e-Mail me
the Articles] - [Search
the Articles]
-
|
