Q: Every year around this time, we have an enormous problem with crane flies. They land on the side of the house by the hundreds, and when we walk on the lawn, it seems to stir them up. At times, we have to swat a pathway for ourselves just to get from the garage to the car in the driveway.

I'm not sure if it's a problem with the neighbor's yard as well, but we've been dealing with this crane-fly infestation for the past four or five years. Is there anything we can do? I know that crane flies are harmless if they get inside. It's just an extreme nuisance when we're outdoors. Any ideas on what causes it and how we can get rid of it?

A: Even though thousands of species of crane flies cover the whole country, they have the same general life cycle. The adults look like huge mosquitoes but don't eat or do much harm; mainly, they're a nuisance when they swarm around lights and cover lawns or buildings. They lay eggs that may hatch in fall or spring, and during the spring and summer, the larval stage feeds on decaying organic matter or plant roots. They spend some of the summer in the pupa stage before hatching out as adults again.

The larvae look like worms or slugs and can grow to be as long as three inches. Their tough outer coating sometimes gives them the name leatherjackets. They may be abundant in compost piles, lawns, drainage ways that are wet or flooded some of the time and in streams or ponds. The truly aquatic species are not found in polluted waterways and are indicator species of higher quality water.

Even though they can be very common, the larvae generally feed unnoticed to humans and don't damage most lawns to a point requiring chemical controls. They are fed upon by many predators, from fish to moles to ground beetles to birds and bats.

Since yours aren't noticeable pests until they're adults, you can use a general vapor pesticide to spray them. You'll have to look at your landscape to decide where the larval stage is feeding in the spring to see if you can nip the problem in the bud. Since so many other animals feed on them and they do so little damage, you may decide to treat only the adults, if necessary, in some years.

In a healthy lawn, more than 30 larva may feed in an area the size of a sheet of paper before you reach a threshold of damage requiring chemical treatment. An already unhealthy lawn could tolerate only half that number.

Q: Our maple tree developed a vertical crack, and we recall that you said we should wrap it in the fall. Is that correct, and what do we wrap it with?

Answer: Maples, especially Norway maples, are very prone to this cracking, but I have seen oak, ash and other forest trees with the same problem.

What happens is that the thin bark allows the live tissues between the wood and the bark to warm up when the winter sunshine aims directly at the trunk, causing cells to start growing. During the winter, however, the cells are supposed to be dormant and full of carbohydrates that act as anti-freeze. Cells warmed by the sun use the anti-freeze sugars for cell activity, so when the sun sets and the temperature of the trunk drops, the cells don't have enough anti-freeze. As ice forms in the cells, they crack.

To protect the tree and to promote healing, wrap the tree with a silver or grey paper tree wrap every winter until the crack is sealed. Take off the paper every spring after the leaves are out so that insects and disease organisms can't find refuge under the wrap. Without additional cracking each winter, the healing tissue will eventually grow across the crack. Don't use any kind of paint. It just hides the disease and insect organisms and does not benefit the tree.

Email questions to Jeff Rugg at [email protected]. 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.