The budding tree limbs high above my neighborhood are still disfigured by the untidy brown remains of webworm nests. The pests had a great year in 2007, producing three generations of the hairy, inch-long worms that spun their webs bigger and bigger to encompass the leaves that are their dietary requirement.

The thick, dirty-gray webbing acts as a shield against predators and the weather. Once the webworms eat the leaves within the original web, they enlarge it to take more food supply under cover.

FILE 2007/Staff photo

North Texas trees suffered at least three generations of webworms and their unsightly nests last year.

Last year's drought-busting rains in spring and summer produced a lot of verdant, tender foliage that supported a vast increase in the webworm population. It stands to reason that at least the first generation of caterpillars this spring will be a bumper crop.

When homeowners began noticing the webs on the ends of tree branches last spring, it was too late to take preventive measures. Entomologists suggested we cut off the infested tips of branches and dispose of them. Or, break open the webs high up with a long pole so the birds, a natural predator, could get at them. For the webs high up in venerable pecans, well, webworm infestations don't usually kill a tree.

JOHN F. RHODES/DMN

The webworm does not sting, but its silky whiskers may be unpalatable to birds.

I tore open the webs I could reach and waited. I didn't see any birds gorging on caterpillars. Ever. By summer, webworms were falling on my head like raindrops. I picked up the delicate creatures covered with silky white filaments and offered them to my garden chickens. Each hen turned her head to one side to give the whiskery thing a close, one-eyed scrutiny, then walked off, fluffing her feathers in a harrumph.

My chickens love worms. They fight over mealworms, grubs and cabbageworms, stealing them from each other's beaks, even. They scratch for earthworms in the compost heap and risk getting their feet chopped off by a shovel blade, looking for worms I might unearth when digging a plant hole.

Not one showed interest in a webworm. I tossed a few to the goldfish. No deal there, either.

Dr. Wizzie Brown, an entomologist in Travis County with the Texas AgriLife Extension Service, wrote last year, for the Austin American-Statesman, that "birds are deterred by the furriness, so the only natural predators are parasitic wasps and flies."

Now that the trees are leafing out, the webworm moth will have a place to deposit her eggs. You can search the undersides of leaves for the minuscule eggs, laid in a dense group, and remove and bag the affected leaves. But how practical is that?

Dallas organic gardening expert Howard Garrett pins his hopes on the release of trichogramma wasps, a biological pest control. A small card that looks like a piece of black sandpaper is covered with 3,000 or more moth eggs parasitized with trichogramma wasp eggs. As the wasp larva develops, it kills the host egg and emerges to feed on and parasitize other eggs, ideally those of the webworm moth.

The cards can be purchased for about $5 each at local garden centers that carry organic products. If you have enough like-minded neighbors, online sites such as www.buglogical.com sell the cards in bulk for a little more than $1 apiece.

One card per week for three consecutive weeks should be enough to treat the average property, says Mr. Garrett. At www.dirtdoctor.com, he suggests applying the card at dusk, on the south side of the tree, preferably in a shaded spot where direct sunlight will not hit the cards. Attach the strip to a tree twig with a wire or pin to a tree trunk. The wasps normally hatch in 24 to 48 hours. Avoid making releases under extremely hot, cold, rainy or windy conditions.

The drawback is that the wasps parasitize only the eggs of the webworm moth, not the caterpillar, killing them before they hatch. That means timing is critical. If you're going to try it, do it now.

If the hatched wasps do not find webworm eggs in time, your landscape still could gain from the introduction of the beneficial insect. It parasitizes eggs of aphids, armyworm, cankerworm, cabbage looper, leaf rollers, gypsy moths, mealybugs, scale, whiteflies and various beetle larvae.

There have been no scientific studies evaluating the efficacy of trichogramma wasps as a control for webworms. Texas AgriLife Extension, therefore, does not recommend the practice as an effective tool against them.

Dr. Allen Knutson, a professor and extension entomologist in the Dallas office, explains in an e-mail that studies evaluating trichogramma releases to control other pests did not produce significant results.

Trichogramma mass-reared in labs, he says, lose the behavioral characteristics needed to be effective. Second, there are many species of trichogramma, and it is critical to release the species that is best adapted to the target pest, habitat and climate. Third, fire ants are common in pecan trees, he says, and they "quickly eat the trichogramma pupae glued to cards and placed in trees."

He also warns that the wasps "can attack eggs of many moths and butterflies, so there may be some risk to these nontarget species." Butterfly gardeners will be dismayed by that potential outcome.

It seems like a war that, so far, the worm is winning.