[AG] Palo Verde Web Worms

Linda A. Guy laguy2@primenet.com
Thu, 11 May 2000 07:19:25 -0700

We just learned about these yesterday morning from Ag Agent Terry Mikel at the Monthly Update for Master Gardeners. We're not sure why there are more of these this year than most, but this cousin of the tent caterpillar has been noted valley-wide and in particular Terry is receiving worried calls from nurseries who anticipate trouble selling impacted trees in the short term. [It's hard
for them to tell a customer 'trust me'.] These web worms target the palos [breas and verdes] and old/new world acacias [excl. Australian]. If you have these, check them out, too.

HOWEVER, this is strictly cosmetic damage, and Terry assures us that the branches will eventually leaf out, so do not prune them away. Web worms will focus on the tender new ends at the terminals, so unless the tree is very young and you fear that the infestation will have a dramatic impact, you have several options. Leave the tree alone. Spray well with water to hose them off. Use Bt
[bacillus thuringiensis] which is the traditional organic approach to any caterpillar. Or use Sevin. Terry notes that the best time to spray is after sundown, since these are nocturnal critters.

Avoid the temptation to overwater these native trees. You'll just produce more luxuriant and voluminous vegetation to have to prune.

Take heart in knowing it is nothing that you did, that you are not alone!

Linda Guy
Master Gardener

Kamerakaye@aol.com wrote:

> arid_gardener
> My young palo verde trees are suffering from some kind of parasite...the ends of the branches are covered with a sinewy, spider-web-like substance which is encasing what leaves are there.  One of the trees has no leaves at all.  They all receive regular irrigation...one is a Sonoran palo verde and two are blue palo verdes.  What can I do to treat the trees before more damage is done?
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