Hemlock Woolly Adelgid

The Hemlock Woolly Adelgid (HWA)

The Hemlock Woolly Adelgid (HWA) is an invasive, aphid-like insect which feeds on the hemlocks’ stored starches and is identified by the white, cottony wax the adelgid produces. HWA was discovered in the eastern states in the early 1950s and has been spreading ever since. Recently, HWA has been identified in Muskegon and Ottawa counties.

HWA feeds along the twigs of hemlocks by inserting its mouth part into the tree tissue and feeding on starch reserves. Over time, the tree will lose vigor and may eventually die. It is spread by migrating birds, mammals, humans, and infected nursery stock.

Once established on a hemlock, the HWA reproduces asexually and can quickly cause a mature hemlock to decline.

Once the HWA is identified, Integrity Tree Services can help control it by several means. Trunk sprays and soil drenches of insecticide have been shown to lower HWA populations. We treated hemlocks on several properties last year and we are looking forward to seeing the results.

Be on the lookout for the invasive HWA. Located under the branches, the insects will appear as white, cottony masses along the twigs at the base of the needles. Do not attempt to move the insect or try to take care of it yourself, because this can spread the pest