We have a large tree, over 50 ft. tall, in our yard. It has been very hot
and dry here for several weeks....100+ heat index. The trees leaves have
started turning brown, so I thought it might be needing water. Looking close
at the tree, I found that almost all of the tree branches, from the smallest
down to the trunk, are coverered with what looks like a very fine spider
web. Also, many of the leaves have a white granular substance on them. It is
killing the tree rapidly, but not by cutting off the sunlight, because the
web is so thin, surely it is still getting enough light. Anyway, I could not
see that it was encasing the leaves also. What is causing this? Sorry, I
don't know what kind of ttree it is, but it is not an evergreen, and never
has any fruit or blooms. No other trees in my area seem to have this,
either. There are three other trees on my lot, and they are all fine.
Tent caterpilliars usually only make tents in the crotches of trees and by this
time of the year they have already pupated, emerged, and are near laying eggs.
You may want to look up "Euonymus caterpilliar" which is a pest that is known
to cover an entire plant with thier large webs. This is the right season for
them as well. You may also have an incredible infestation of giant mutant
alien spider mites.
It sounds very much as if you have tent caterpillar -- check the
webs just after sunset and see if they have lots of little
caterpillars in them. A tree can generally survive one round of
defoliation if it is gently cared for following removal of the
infestation. In any case, treating a 50+' tree is not a DIY;
call a tree specialist.
Jim Caldwell wrote:
If the webs are only on the branches and not the leaves, it is
probably what I saw in Houston not long ago. I forget what the cause
was (some insect, obviously), but more than one source I looked at
said it is harmless and should not cause any alarm. Try looking
around on the Houston Chronicle web site for more definitive answers.
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