Hemlock aphids

Asked June 13, 2016, 10:00 AM EDT

Is there someone I might talk with about strategies concerning hemlock health? Thanks, David Newbury (East Thetford; 802-785-3136 or dnewbury@smith.edu)

Orange County Vermont

4 Responses

Hello,
Here is a link to a USDA publication on managing hemlock woolly adelgid (aphids) - http://fpr.vermont.gov/sites/fpr/files/Forest_and_Forestry/Forest_Health/Library/ManagingHemlockNort...

Additional information can also be found here.
http://fpr.vermont.gov/forest/forest_health /insects_diseases#Invasive%20Forest%20Pests

You may contact me if you need additional information.

Mary Sisock
802-656-1721
msisock@uvm.edu






Thanks, Mary. I appreciate your quick response. Looking through the materials you linked me to, I think I may be dealing with "spittlebug," for these were large moist accumulations of "sudsy" material, each with one or several "slug-like" bugs within. They could be noticeable, often of 1/4 inch (and sometimes up to 1/2 inch) long, and had the appearance of a maggot: very fatty. Is this something I need to worry about? Til now, I've tried to pick them off individually, by hand, crushing the bugs in each "spittle-cloud." Am I spreading them by so doing? And will they kill the tree? Thanks, David Newbury.

Hi David,
If you are seeing white frothy masses, particularly at the base of new shoots, it is likely that what you are dealing with is pine spittlebug. Spittlebugs are not considered a major pest and do not require treatment most years. Spittlebug nymphs and adults feed of the sap in tender new growth. Damage inflicted by this insect is minor on healthy trees. If the infested trees are part of your landscaping, you can continue to control this insect by crushing the larvae as you have been doing. If you are noticing twigs with spittle masses dying, you can wait until the adults emerge in early July (if most of the spittle masses are empty the adults are out) and treat once with an insecticide.
Mary

Many thanks, Mary. That was very helpful. (And a relief that these spittlebugs are not serious; I'll continue to try to address this manually, and hope that this hemlock (which seems in vigorous health) can muster its own strength to prevail. Thanks again. David Newbury