on forested land in Latah and Benewah counties. The Tussock Moth is a forest
insect native to our area and outbreaks are a natural occurrence, usually appearing
every eight to ten years. Caterpillar larvae of the Tussock Moth feed on conifer
needles (mainly Grand fir and Douglas-fir) in June and July, causing defoliation. In
pockets of intense defoliation tree loses are severe. Over the remaining areas,
direct mortality is rare but defoliation weakens trees causing loss of growth,
deformity, and subsequent mortality from other agents such as bark beetles.
indicated the Tussock Moth
population to be high, and a
severe infestation occurred
in 2001. Working with the
Idaho Department of Lands,
Bennett Lumber sought to
address the problem. The
State Land Board authorized
funding of $2.6 million
dollars for a widespread
spray program using a
caterpiller specific insecticide.
Private landowners were
asked toparticipate in the
cost at the5% level.
