Douglas Fir Tussock Moth Spray Project

[Tom Trail <ttrail@moscow.com>]

Visionaires:

Last year there was a great deal of damage caused by tussock moths in the
Latah-Benewah
County areas.   The State of Idaho provided $3 million in deficiency
warrants to cost share
with private owners to spray the moths.

Larry Ross, Palouse Ranger District, provides us with this update.
"Tussock moths are native
insects.  Outbreaks occur in this area on eight to 12 yr. cycles.  The
Forest Service in partnership with the State has an early warning system
set up to dtect the beginning of these outbreaks.  In 2000, at the onset of
this outbreak, the FS prepared a Biological Evaluation.  Based on this
study, I elected
not to spray for a variety of reasons.  IDL, using their own information,
elected to spray a large area of State and private holdings in Latah and
parts of Benewah County.  During 2000 and into early 2001, the FS continued
monitoring the popoulation and prepared another Biological Evaluaiton.
This BE clearly indicated that the population was poised to begin a rapid
decline.  Further monitoring
througout the winter and spring of 2002 added data that supported this
conclusion.  In early summer 2002, the State aerially sprayed about 30,000
acres for tussock moth.  However, there was no
significant hatch of tussock moth.

The forest Service has established long term monitoring plots in the areas
most heavily defolliated in 2001.  We will track the condiitons of
individual trees on these plots for five years to obtain information on
survivability.  Nearly all trees affected will refoliate.  Howver, past
research indicates that some trees that refoliate following a tussock moth
oubreak and look healthy die within 3-5 years.  These long term plots will
give us valuable information to make decisions during future outbreaks.
The FS is alos helping fund the U of I to do long term research on areas
affected by the tussock moth on the u of I's experimental forest to answer
other management questions.  In addition, we established a large number of
short term plots last year throughout the forest in the areas most heavily
affected by tussock moth that we are just completing reading.  The formal
results are not written up yet, but the crews are reporting that there are
very few tussock moths to be found and that most trees have refoliated and
appear to be healthy.

It should be noted that for 2001, the data indicated extremely heavy
infestations on private lands in the Moscow Mtn. area in Latah, County
while the same data set showed very low to non existent populations on USFS
lands.  In other words, for 2001, private lands were, for some unknown
reason, much more heavily infested with tussock moth larvae than USFS
lands.  As a result, the USFS had more management options available to
address the Tussock Moth problem than some private landowners did and IDL."

My brother and I have some land on Moscow Mt. and we worked with the state
spraying program
last year.   The program was very effective and it appears that trees
suffered little damage.  This
year we only spotted on tussock moth larve so apparently the cycle in on
the downward slope.

Rep.Tom Trail/Dist. 5

Dr. Tom Trail
International Trails
1375 Mt. View Rd.
Moscow, Id. 83843
Tel:  (208) 882-6077
Fax:  (208) 882-0896
e mail ttrail@moscow.com