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20 year old linden tree has a major problem: Help! #416732

Asked July 25, 2017, 1:14 PM EDT

My linden tree has a problem: eaten leaves, sticky substance falling on cars parked under it and on the sidewalk; lots of lady bugs and I did see some1" wormlike bugs with a reddish horizontal stripe. Didn't see the worms today. I planted toe tree and do not want to lose it. Help!!!

Hennepin County Minnesota

Expert Response

The sticky substance, the distorted leaf I see in one photo, and the lady beetles are all related. Your tree has aphids on it. The leaf distortion is caused by the feeding. The sticky substance is honeydew, the aphid excrement. The lady beetles eat the aphids.  Read here:
https://www.extension.umn.edu/garden/insects/find/aphids-on-deciduous-trees-and-shrubs/
Usually, no control is necessary for aphids.

The ragged holes I see could be hail damage but could also be Japanese beetle damage. Lindens are a favorite of Japanese beetles. The leaves you've shown don't look seriously affected. Japanese beetles can skeletonize the leaves of the tree. Read here:
http://www.extension.umn.edu/garden/insects/find/japanese-beetles/

The "worm" you saw could be a linden looper. This larva could also be the cause of the holes in the leaves. Usually the damage is minimal:
https://www.extension.umn.edu/garden/diagnose/plant/deciduous/linden/leavesholes.html

If you keep the tree healthy by providing water during dry spells and mulching around the base, your tree should survive these pests.




Dennis in St. Louis Park Replied July 25, 2017, 2:11 PM EDT

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