I just glanced outside and seen that my 7 year old apple tree has these worm things on it, they have combwebs around them and are a pale yellow color, http://www.gardenstew.com/plantstew/gar ... r_id=19769
Looks like webworms. We burn them off when we get them. Just roll up some newspaper, light it and hold it under the web. Doesn`t take long to burn the web and the worm off. Make sure you are not in a drought area to do this. Don`t want to catch the world on fire,, or the rest of the tree. As long as the tree is well watered all you will lose is maybe a few leaves.
After you eliminate the current webworms, spray with a bug killer. And always have a water hose handy when burning the webworms off.
Hm. I'm thinking Gypsy Moths. Is "webworm" the common name for the gypsy moth larva? Bad memories of those little guys.
What does BT stand for? I was reading some comments on these green worms & we have pets so need to be careful what we use on plants as we found these green worms on the cats' catnip leaves!
Bacillus thuringiensis. It's a bacteria, strains of which kill various insects: silkworms, beetles and flies, for example. Organic farmers are big on it, since it's a non-synthetic insecticide. You can use it without fear of it harming domestic animals since its very specific in what it kills.
Here in Wisconsin we would call those crummy little crawlers "tent caterpillars". If left unchecked they can defoliate a small tree or shrub in just a few days. We take care of any of the webs or tents that we see with a hand held propane burner. The kind you can buy for hobby projects.
Fall Webworm is Hyphantria cunea Eastern Tent Caterpillar is Malacosoma americanum Western Tent Caterpillar is Malacosoma californicum Forest Tent Caterpillar and Sonoran Tent Caterpillar are both Malacosoma tigris And we have all of those those in different parts of Texas Gypsy Moth is Lymantria dispar If you don't want to use sprays of any kind or fire (down here way too dry to try to burn them safely) you can also take a stick or tree branch to break open the web so wasps can reach the caterpillars and feast on them.
Those are definitely tent caterpillars, also known as web worms. There are natural ways to get rid of them like neem oil or burning them off the tree.
BT is baccilus thurengsis, a bug killer used at the larval stage. Is is often mixed with water and applied with a spray bottle. it meets organic practice if you follow directions.