Q&A.

Q. I've just found little sticky, cottony things on the leaves of six of my 12 African violets. A friend says they are mealybugs. Where could they have come from? How can I get rid of them?

Pests get into homes by hitching a ride. They could have been on a guest's clothing, for example, or they could have attached themselves to your clothing as you walked through a florist shop, a friend's home, or any store that has plants. They could even come in on shopping bags or items that were near the plant department.

It takes only a single egg or one of the other stages in the bug's life cycle. The mealybug has a crawler stage which is very mobile.

Isolate the plants that appear to be affected. If they have only a few insects, touch each cottony mass with a cotton swab that has been dipped in rubbing alcohol. This will destroy the pinkish insect underneath.

For more serious infestation, you can fill a deep pan with the following solution: 1 tablespoon each of liquid detergent and hot pepper sauce, plus 1 pint of rubbing alcohol, to a gallon of water. Then, by inverting the pot (and holding on to the soil ball), you can immerse the plant in the solution.

Swish back and forth and up and down. Repeat at weekly intervals until the insects are gone. Wash all areas where the plants set as well.

Q. Recently we were looking at the moon through the leaves of our tall maple trees. Thinking they looked rather skimpy, the next day we used field glasses for closer inspection. It looks as if something had eaten large sections out of each leaf in the taller portions of the tree. We recall seeing small greenish worms suspended on silk threads after the leaves were fully out, but paid little attention to them because we've seen these worms each year (perhaps not so many). Could they have done this damage? What can we do to prevent it next year?

Your trees were likely damaged by either spring or fall cankerworms, a very serious problem in many areas this spring. The larvae of both are active in the spring. Spring cankerworm moths lay eggs in early spring, the other in late fall.

Female moths of both are wingless and crawl up tree trunks to lay eggs in the crevices of the bark. Common in many regions of the United States, they feed on both fruit trees as well as shade trees.

The worms may vary from brown to greenish with stripes. In most years their numbers are not great enough to do much damage, but every few years the population growth can become serious.

Be prepared next year to spray the trees with Bacillus thuringiensis, which works only on the larvae of moths and butterflies, but is harmless to insect predators, wildlife, humans, and pets. You may find it in garden centers as BT, Dipel, Thuricide, or other names, but it always has the scientific name on the label.

Q. Last year, after the beautiful autumn foliage had already fallen, I read about a solution in which tree leaves and other plant foliage can be dipped so that it could be preserved indefinitely. I like to make dried flower bouquets from nature's bounty and the foliage would add so much to them. Can you give the correct information?

The solution to use is 1 part glycerine and 2 parts water. Hard-surfaced leaves and glossy ones do best, but you can try others. A few are lily-of-the-valley, pachysandra, ivy, peony, and iris. Most tree and shrub leaves come out well.

Small leaves and short sprigs can be laid down in the solution. Large ones can be stood in a container if the solution reaches 4 inches up the stems. If the stems are woody, pound the lower couple of inches with a hammer to crush the bark.

All foliage darkens somewhat and the process takes about a week. The solution can be used over and over until it's all gone.

Q. We have been finding large ants in our home and believe they come in on the firewood. Is it safe to spray the wood (which is now in the basement) with a pesticide?

Never spray firewood with insecticides as it could give off toxic fumes when burned. It is best to inspect the wood as it is brought into the house. Solid pieces with no holes should not bring pests inside. Decayed wood may bring in powder post beetles, carpenter ants, termites, and other insects.

You can spray around the area where the walls meet the floor with a roach-ant spray, avoiding the wood. Take care not to breathe the fumes and have as much air circulation as possible.

If you have a question about your garden, inside or out, send it to the Garden Page, The Christian Science Monitor, One Norway Street, Boston, Mass. 02115.