Hemlock Woolly Adelgid (HWA) Ovisacs - Adelges tsugae

The white fluffy things at the bases of these hemlock needles are HWA ovisacs. They make the woolly covering to protect themselves and their eggs.

HWAs are invasive insects that feed on hemlock trees, which causes the needles to desiccate and prevents the growth of buds. This prevents new growth and causes tree death within 5-10 years.

Hemlocks are a keystone species. They provide shade, shelter for animals, they cool the streams that they grow over, help prevent erosion, and they are a source of food. They are a vital part of the New England forest system. The HWA is a major threat to the health of the trees.

Habitat: Eastern hemlock (Tsuga canadensis); mixed forest

comments (2)

Ferdy Christant

Lion

Education but saddening post, thanks for writing it! Is there any counter measure against them? Posted 3 years ago
1. Christine Young
  
  Lion
  
  Good question! There are many things that can be *attempted* to control Adelges tsugae. Chemical control (pesticides) is one way, but not always safe or feasible if the infestation extends over a large area. Biological control (releasing insects that are natural enemies of Adelges tsugae) is another method that can be helpful. Conserving/developing a host resistant strain (finding a strain of hemlock that is resistant to the pest, saving the seeds, and then repopulating with those resistant seeds) is another control measure. Ideally, the best way to control adelgids is probably IPM (Integrated Pest Management), which uses a combination of control measures to ensure success. Posted 3 years ago, modified 3 years ago

The Hemlock Woolly Adelgid

The hemlock woolly adelgid, or HWA, is an insect of the order Hemiptera native to East Asia. It feeds by sucking sap from hemlock and spruce trees. In its native range, HWA is not a serious pest because populations are managed by natural predators and parasitoids and by host resistance. In eastern North America it is a destructive pest that threatens the eastern hemlock and the Carolina hemlock.

Info 5 0

Similar species: True Bugs

Species identified by Christine Young