Bagworm on Arborvitae

At Fox we’re seeing a mini-outbreak of bagworms on arborvitae, spruces and even on some Japanese maples. Ugly brown spindle-shaped bags can be seen on the tips of foliage and twigs where the bagworm moth has laid eggs which have hatched, penetrated the foliar tissue and are now formed into pouches housing the bagworms (larvae). If not taken care of, these insects will cause woody ornamentals to become unsightly, thin out the foliage, and eventually kill the plant. Because bagworms are limited in their ability to travel, huge populations can develop on a single plant. Usually, the best control comes from treatment in early June to kill the insect in it’s early larval stage, but systemic treatments may be effective throughout the year. If the population is large, we recommend immediate treatment followed by a treatment the folowing June. An alternative when populations are smaller is to manually remove the bags in fall and winter and dispose of them. Call us today if you’ve seen this problem on any of your trees