Wasps and trees (Linden?)

Asked August 13, 2016, 1:35 PM EDT

We are new owners in a new development just west of downtown Littleton. One of the HOA trees, next to our property, has wasps eating the leaves. I was told a water solution with mild dish soap sprayed on the leaves will keep the wasp away. If this is true, what would be an appropriate ratio? Thank you!

Arapahoe County Colorado

1 Response

Not true. Soapy water sprayed onto soft-bodied insects (like aphids) may kill them. Insects knocked off of leaves into a bucket of soapy water may drown because they cannot exit water with lowered surface tension due to the soap/detergent.

Wasps don't eat leaves. My guess is that you have other insects, possibly Japanese Beetles, eating the linden leaves, photo below.

Yellowjacket wasps are attracted to sticky-sugary "honeydew" excreted by aphids on the linden leaves. Aphids are very common on linden tree leaves. Look to see if any linden leaves look shiny wet and sticky; these have had aphid honeydew dripped onto them by aphids on leaves above.

CSU Extension information on insecticidal soaps, Japanese Beetles and aphids in shade trees:

http://extension.colostate.edu/topic-areas/insects/insect-control-soaps-and-detergents-5-547/

http://extension.colostate.edu/topic-areas/insects/japanese-beetle-5-601/

http://extension.colostate.edu/topic-areas/insects/aphids-on-shade-trees-and-ornamentals-5-511/