By CSKT Tribal Forestry
Douglas-fir Tussock moth has been located in several locations throughout the reservation. The moth is a defoliator (eats and damages the needles) that feeds on Douglas-fir, true fir, and spruce trees. This pest is one of the easiest to identify. Adult male moths are a non-descript, gray-brown moth with feathery antennae and a wingspread of 1-1 1/4 inches. The female is flightless and notably different from the male in that it has rudimentary wings and a large abdomen, usually about 3/4 inch long. Young larvae possess fine hairs; older larvae have two tufts behind the head, one posterior tuft, and four dense tussocks located along the back. Larvae grow up to 1 1/4 inches.
The effect of these pests is the partial or complete defoliation of trees. Tree mortality is not guaranteed. In fact, the affected trees usually recover.
The timbered lands on the reservation last had large populations of tussock moth in approximately 2005 in the Jette area, Oliver point, near the Bison Range and large scale mortality was only witnessed in the Oliver point area. The reason for the mortality was that a secondary pest, Douglas-fir Bark Beetles, killed the weakened trees.
Currently, tussock moth has been located in Pistol Creek, near and on the Bison Range, Selow Creek, Ferry Basin, Garceau Gulch, Elmo, Big Arm, Irvine, and the Big Draw. If concerned citizens see other outbreaks, please contact Tribal Forestry at 676-3755 and leave information.
Affected defoliated trees may look dead but have a high probability of recovering. Fuelwood cutters should be careful not to cut trees that may still be green and not ready to be utilized as fuelwood.
Warning: Hairs on the tussock moth larvae can cause an allergic reaction in humans. The most common reaction is a skin irritation. Rashes, watery eyes, and sneezing are common symptoms. Avoid handling the larvae, and wash after exposure.