In Michigan, Christmas tree growers who ship trees out of the state must comply with federal and parallel state quarantines for gypsy moth and pine shoot beetle. Neither of these pests cause economic or even noticeable damage in managed Christmas tree fields. Their importance lies in the fact that they are exotic and not yet distributed throughout the country. A regulatory treatment is a mandatory pesticide application required by the USDA and MDARD to assure proper control of gypsy moth in what the USDA refers to as "hazardous sites". These are defined as sites where gypsy moth is present on the premises and/or in the surrounding area.
Christmas tree Inspection and Certification Michigan Department of Agriculture and Rural Development (MDARD)
Trees must be inspected by state regulatory officials (MDARD) just before harvest and certified free of gypsy moth before they can be shipped. MDARD will inspect trees only if growers apply an insecticide spray during the gypsy moth larval development period. Trees that do not pass the inspection process cannot be sold outside the area under the gypsy moth quarantine.
Pine shoot beetle
The Pine Shoot Beetle Compliance Program involves a field-tested, integrated management program that relies primarily on cultural controls such as trap logs and destruction of brood material. It does, however, mandate one insecticide application, even if pine shoot beetle populations are low or undetectable within the field.
- Balsam Twig Aphid
- Cooley spruce gall adelgid
- Douglas-fir needle midge
- Spruce gall midge
- Spruce spider mite