worms eating red leaf sugar maples

rfwms · June 01, 2005, 10:07:44 PM

My son-in-law has several red leaf maples that are being stripped of their leaves by a worm about 2 - 2 1/2 inches long. It is green with black stripes on its' back and has a red head and a hint of red on its' body. What kind of worm is this? It resembles a catawpa worm!

populus · June 01, 2005, 10:31:45 PM

Depends on where you are, but it could be the green striped mapleworm. Look at this picture. It generally does little damage as the trees have time to grow new leaves.

beenthere · June 01, 2005, 11:19:38 PM

I have just discovered yesterday that the N. red oak leaves on about 1500 of my 6-year old oaks have been eaten, or at least partially 'gone'. Leaves at the tops of the trees, some 12' tall, are just about completely gone. Sent a note and picture to the District Forester to try to get a lead on what is causing it. Could not find a single critter (caterpillar or otherwise) that would be munching the leaves, as that appears to be what is happening. Can't believe it would be frost, although the lower leaves on the trees don't seem to be affected. The oaks are intermixed with white spruce and white pine on about 5 acres.

I had some SEVIN and sprayed each tree yesterday to try to get ahead of whatever it was or is. Seems quite early to have new leaves eaten that way. There are new leaves budding out, and some the size of 'squirrels ears', so the tree is trying to recover.

populus · June 02, 2005, 06:22:20 AM

My general recommendation when your trees are defoliated in the spring is DON'T PANIC. Trees maintain enormous stores of starch and protein and can quickly make new leaves. A healthy white oak contains enough stored food to make about 8 new crowns, so a single defoliation usually is not a major problem.

There are exceptions. Late season defoliations are more risky, since the tree might refoliate and the tender new leaves could get hit by frost. Trees weakened by drought or disease could be unable to refoliate or succumb to secondary agents of mortality like chestnut borers or Armillaria root rot. Hemlock trees, unique among trees, are unable to grow new leaves after being defoliated and will die. Very young trees (1-3 years old) may have reduced growth or be unable to recover.

Otherwise, a spring or early summer defoliation is probably the equivalent of a head cold - uncomfortable but not fatal. Most spring defoliators disappear pretty quickly, which may be why you aren't seeing anything. Effects on tree growth are usually minimal.

I definitely DO NOT recommend spraying insecticides for spring defoliators, especially if you can't see the insect. Spraying is usually a waste of money, doesn't benefit the tree and causes harm to beneficial insects.

beenthere · June 02, 2005, 09:12:06 PM

populus
A ""Regional Gypsy Moth Suppression Coordinator "" contacted me today, and confirmed that the damage to my red oaks was likely due to frost. We had a very warm month of April, the new leaves were out, and then some frost hit in early May. A lot of damage to the alfalfa fields as well. It fits the pattern of the tops affected, but not the bottoms, hit all the oaks across the entire 'field', took out some stems as well as leaves, couldn't find any critters, and new growth is replacing the damaged crown.

I shouldn't have reacted (paniced) so fast with the SEVIN, but I had it, had the time, and didn't want to lose any more oak leaves. :

They sure appeared to be eaten, just like a caterpillar does its work.

But the frost was the culprit, we're pretty sure.