- Asian Longhorned Beetle
- Anoplophora glabripennis
- Elm Zigzag Sawfly
- Aproceros leucopoda
- Emerald Ash Borer
- Agrilus planipennis
- Fall Cankerworm
- Alsophila pometaria
- Forest Tent Caterpillar
- Malacosoma disstria
- Hemlock Woolly Adelgid
- Adelges tsugae
- Ips Bark Beetles
- Ips spp.
- Sirex Woodwasp
- Sirex noctilio
- Southern Pine Beetle
- Dendroctonus frontalis
- Spongy Moth
- Lymantria dispar
- Spotted Lanternfly
- Lycorma delicatula
Environmental Risks to Arthropods from Imidacloprid Applications for Hemlock Conservation
Managing hemlock woolly adelgid (HWA) (Adelges tsugae) can involve use of insecticides. The negative environmental consequences of hemlock mortality must be weighed against the known consequences of insecticide use to preserve hemlocks.
The hemlock woolly adelgid, originally from Asia, was first discovered in the eastern U.S. in the 1950’s. It has since spread throughout the range of hemlock in the East, and caused extensive mortality of mature hemlock – especially in the Appalachian Mountains. This small, aphid-like insect produces a white tuft of cotton-like substance, making them easy to see on the dark green background of hemlock needles. Immatures, or crawlers, are only mobile for a short time during which they disperse by crawling or by wind. Once they find a suitable spot, they insert their mouthparts into the tree and remain there the rest of their life. Control is difficult, but high-value trees can be protected with soil-drench or stem-injectable insecticides. Natural enemies provide some management, but many efforts now are toward developing resistant hemlock selections with which to replant areas devastated by the insect.