A Greener View by Jeff Rugg

Q: My evergreen arborvitae is turning a grayish green. I am wondering what could be wrong with it.

A: Since most insect and disease symptoms turn a leaf yellow or some other color than gray, I have a suspicion that the problem is spider mites. They are smaller than a grain of ground pepper and very hard to see. The damage caused by mites is also very small. They feed by using a piercing mouth sort of like a mosquito; they suck out the green juices of the plant causing very small off-color dots.

Under a magnifying glass, you will see the green plant is full of gray or brown dots. It may take a magnifying glass to see the mites, but they can be seen on a piece of paper if you slap the branch on it.

Mites are common on many indoor and outdoor plants. The population builds up in just a couple of weeks if there is no rain and warm weather. Washing the plant with the hose outside or using the shower inside will reduce the population to manageable levels.

Most insecticides are not miticides, so spraying them with the common insecticides will probably not work. Find a miticide that lists arborvitae (or other plant you want to use it on) on the label, if you decide to go that route.

Q: My pantry shelves have become infested with a small brown moth. I think they came in with the bag of birdseed. After I clean my pantry, how do I get them out of the birdseed?

A: The moths are probably one of two types. Both Indian and Mediterranean meal moths are found in grain products. They are brown to gray and about one-half inch long. They fly in a very haphazard manner that makes them hard to hit, but once hit, they are easily killed. They are not attracted to light, but they are more active at night. The meal moths are not attracted to clothing.

The eggs, larvae and adults can be found inside of whole grain seeds, such as those found in wild birdseed, pet birdseed and small rodent pet food (gerbils, etc.). They also eat a lot of other foods found in the pantry. Who doesn't have an open box of some of these foods in the pantry right now: nuts, grains (rice, wheat, etc.), flour, breakfast cereal, dried soup, crackers, dried fruit, powdered milk, red peppers, candy, chocolate, tobacco or a bag of cat or dog food?

The problem isn't so much with the adult moths — they may be ugly, but they don't eat much.

They can lay over 300 eggs that hatch into half-inch long caterpillars, which can eat a lot. As they walk around, they leave a silk thread like a spider's web that sticks the food together in clumps and sticks it to the box. When they go into the pupa stage, they weave a cocoon in tight spots, such as under the box flaps, along the junction of a wall and the ceiling of the pantry.

Since many of the insects found in foods are tiny and can be inside the seeds, it is not easy to treat the seeds in such a way that either won't harm the animal the food is intended for or lower the nutritional value of the seed.

There are several ways to deal with these pests in the house. First, seal up all suspected sources of infestation or discard those you can't keep. Put them in the garbage outside, not under the sink, so they can't get away and get back to the pantry. Clean the cupboards and use an insect bomb if you must.

Prevention is the best method of control. For instance, Cole's Wild Bird Products Co. sells its birdseed in airtight packaging that is filled with nitrogen gas. The sealed package doesn't have any oxygen, so no insects can survive in the package of seeds. Keep all vulnerable foods stored in containers that seal tightly and keep them sealed when stored. Inspect packages when you buy them for small holes or signs of insects under the flaps.

Pheromone traps work very well when trying to get rid of moths. These sticky glue traps contain bait that releases a sex scent that only the pests can smell. When full, the trap is easy to throw away.

Once the pests are in a food product, you can try killing them by freezing them, but some stages of the life cycle can survive this treatment. Try at least a week or a repeating schedule of one week in and one week out of the freezer to kill them. This may work on small bags of food like for a gerbil, but doesn't work well on 50-pound sacks of sunflower seeds. Another method is to bake the food at 150 degrees for about a half-hour. Overcooking ruins the nutritional value and it doesn't work too well on chocolate.

Don't worry about a few bugs in the wild bird food; the birds will eat them quicker than the seeds. In fact, seeds in the feeder attract insects for the birds to eat. Sometimes people notice that birds stop using a feeder that still has food visible in it. The insect larvae could have used their silk webs to stick the food together and the birds have eaten all they can reach. So, check to see that the food still flows properly.

E-mail questions to Jeff Rugg, University of Illinois Extension at jrugg@illinois.edu. To find out more about Jeff Rugg and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

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