Monday, August 24, 2009

Creature Feature

Mite You Have A Problem?

Many pests in our garden are easy to observe and attract most of our ire and disgust but there are numberless tiny invaders that we can't see quietly wreaking havoc on our beloved landscape plants. One such pest is barely visible to the eye but can be a major problem during hot and dry seasons and is called the spider mite.

Spider mites are members of the family Tetranychidae and are a diverse set of pests. Probably the most common pest in landscapes is the Two-Spotted Spider Mite (Tetranychus urticae). These little beasts thrive in hot, dry conditions and are especially active from July to August when landscape plants are already stressed. Small members of the arachnid clan, these baddies overwinter as eggs or adults quietly biding their time until the weather warms when they begin their attack by sucking out your plant's valuable juices.

Diagnosis of spider mites is fairly easy. In large numbers they will produce fine webbing. More noticeable signs are the flecking or stippling of leaves which will give foliage a dusty-gray or bronzed look. For more certain signs that you are dealing with spider mites, shake a branch above a white piece of paper. Look closely for small specks moving around on the paper. Also, a quick brush of a hand along the paper will leave red streaks if there are indeed spider mites.

Now that you know what you have, the real problem is control. Avoid using insecticides or miticides as this will kill the spider mite's natural predators, some of which are other mites. Many times after pesticides have been used, the spider mite population explodes due to lack of natural predators which require longer periods of time for them to move back in to an area. It may be necessary to tolerate some level of spider mite damage and just know that when colder, wetter weather hits they will be gone. If control is necessary, try spraying the affected plant with jets of water from a hose. This will create a cooler, wetter environment and will knock them off the plant. Also, keeping your plants well watered and healthy during the summer will help to reduce numbers of this pest.