|Mountain Pine Beetle
Solar Treatment Kills Mountain Pine Beetles in Pine Logs
The mountain pine beetle is increasing in ponderosa and lodgepole
pine forests throughout much of the West. Decades of fire control
have led to overly-dense forests, and now drought has made trees
even more susceptible to insect outbreaks. With pesticides in disfavor,
solar treatments are an effective alternative to minimize beetle
survival and spread in high-value areas such as recreation sites
and around homes. Researchers at the Rocky Mountain Research Station
found that beetle survival was drastically reduced when attacked
trees were felled, cut into 4-foot logs, and exposed to full sun.
Rotating the logs once a week so that all surfaces are exposed to
the sun, or covering the logs with clear plastic sheeting, increased
treatment effectiveness. High temperatures under the bark are key
to killing developing beetles before they can emerge and attack
healthy trees nearby. Beetle-killed trees should thus be felled
in fall or early spring and exposed to hot summer sun to prevent
emergence in August. Uncovered logs should not be stacked; even
plastic-covered logs should not be stacked more than two high.
Negron, JF, Shepperd, WD, Mata, SA, Popp, JB, Asherin, LA, Schoettle
AW. 2001. Solar treatments for reducing survival of mountain pine
beetle in infested ponderosa and lodge pole pine logs. Research
Mata S.A., Schmid J.M., Leatherman D.A.. Sept. 2002. Diesel Fuel
Oil for increasing Mountain Pine Beetle Mortality in Felled Logs.
Rocky Mountain Research Station. USDA Forest Service Research Note
Pine Beetle Brood
(click on images to
mountain pine beetle, Dendroctonus ponderosae Hopkins. Black
cylindrical, rather stout, beetle about 5mm in length.
pine beetle brood lying adjacent to a vertical egg gallery. Larvae
construct their feeding galleries at right angles to the egg
gallery. Larvae, Pupae, and Young adult are seen in their chambers
(slide credited to Jose Negron).
pine beetle egg gallery. Females lay eggs and wedge them on each
side of the gallery with packed frass (slide credited to Jose
remains of a basal rotted ponderosa pine stump. Decay can be
attributed to fungus and insect damage.
Pine Beetle (Dendroctonus ponderosae Hopk.)
Year Life Cycle
The mountain pine beetle has a one year life cycle.
Adult emergence begins about the second week in July and continues
on through September, peak emergence occurring mid August.
The brood will over-winter as eggs and young larvae and continue
their development in early spring. Development
to adults is completed in mid to late July.
||Emergence curves were reconstructed from published Research Notes #32
and #211 authored by W.F. McCambridge, 1964 and J.M. Schmid 1972. Extracted data from Schmid's report were overlayed for easier viewing.
Actual reports are referenced below. (click on graphs to enlarge).
W.F.McCambridge. 1964. Emergence Period of Black Hills Beetles from
Ponderosa Pine in the Central Rocky Mountains. Research Note RM-32,
Schmid,J.M. 1972. Emergence, attack densities and seasonal trends of
Dendroctonus ponderosae in the Black Hills. USDA For. Serv. Res. Note
Identifying Beetle Attacks
of Beetle attacks
(click on images to enlarge)
foliage in late Spring is a sign that ponderosa and lodgepole pine
trees have been killed by the mountain pine beetle. These trees
are called 'faders' and/or 'flag trees' (slide credited to Jose
pitchtubes (resin mixed with frass), on the tree trunk and reddish
boring dust at the base and also in the bark crevices of the tree,
are good indicators of a successful beetle attack (slide credited
to Jose Negron).
beetle attacks are identified by large white pitch tubes on the
tree trunk. These resin tubes may have an embedded adult beetle.
Coarse frass can be found at the base of the tree. No blue-stain
is present and the foliage is green.
damage on beetle infested trees is very noticeable. They make
individual holes in the bark as they search for and feed on beetle
larvae. Woodpeckers will pick out the best brood producing tree
and therefore are good indicators of beetle attacks (slide
credited to Jose Negron).
sapwood of an infested tree will be discolored by a blue staining
fungi; the heartwood will not be stained.
and entrance holes are evident on the bark. Entrance holes will be
visible during the attack period and exit holes will appear the
following emergence period (slide credited to Jose Negron).
F. McCambridge. 1974. Identifying Ponderosa Pines Infested with
Mountain Pine Beetles. Research Note RM-273,pg.1-2.
F. McCambridge. 1967.Nature
of Induced Attacks by the Black Hills Beetle, Dendroctonus ponderosae,
(Coleoptera:Scolytidae). Ann. of Entomol. Soc. of Am. 60:920-928.
(click on images to enlarge)
radiation treatment is an environmentally safe way to kill
Mountain pine beetles. Beetle infested trees should be felled
in June and bucked into four foot length for easy handling
and laid on the ground in an open area where the sun can
heat up the bark. Rotate the logs 1/3 of turn, once every
week before beetle emergence begins in late July.
Our research results indicated that this method has resulted
in better than 95% beetle mortality. Application of diesel
fuel oil to infested logs, arranged in a single row, can
provide better than 90 percent beetle mortality.
tests of insecticides in 1982 determined that spraying green high
value trees with 2% emulsion of carbaryl, as Union Carbide
Sevimol-4 to thirty feet can protect the tree from beetle attacks
(these were the results of research only, and mention of a
proprietary product or pesticide does not constitute an
endorsement or recommendation by the USDA). New insecticides are
now being tested that will produce comparable results at less cost
to the consumer.
Even-aged stands with an average diameter greater than 8
inches in growing stock level (GSL) and of more than 120 sq. ft. basal area in Ponderosa pine
and 150 sq. ft. basal area in Lodgepole pine stands is considered highly susceptible
to mountain pine beetle attacks. Stands thinned to a 100 basal foot per acre or less
can increase protection against beetle attacks.
William F. McCambridge. 1982. Field Tests of Insecticides to Protect
Ponderosa Pine from the Mountain Pine Beetle(Coleoptera:Scolytidae).
J.of Econ. Entomol. 75:1080-1082.
W.F.McCambridge. 1972. Treatment Height for Mountain Pine Beetles in
Front Range Ponderosa Pine. Research Note RM-218, pg.1-2.
W.F.McCambridge. 1981. Duration of Effectiveness of Carbaryl in
Protecting Ponderosa Pines from Attack by Mountain Pine Beetles.
Research Note RM-408, pg.1-3.
W.F.McCambridge and R.E.Stevens. 1982. Effectiveness of Thinning
Ponderosa Pine Stands in Reducing Mountain Pine Beetle-Caused Tree
Losses in the Black Hills--Preliminary Observations. Research Note
Robert E. Stevens, William F. McCambridge, and Carleton B. Edminster.
1980. Risk Rating Guide for Mountain Pine Beetle in Black Hills
Ponderosa Pine. Research Note RM-385, pg.1-2.
William F. McCambridge, Frank G. Hawksworth, Carleton B. Edminster and
John G. Laut. 1982. Ponderosa Pine Mortality Resulting from a Mountain
Pine Beetle Outbreak. Research Note RM-235, pg.1-7.
Cones and Associated Insects
Schmid, J.M., Mata, S.A., and Mitchell, J.C. 1985.
Estimating Sound Seeds in Ponderosa Pine Cones from Half-Face Counts.
Research Note RM-459, pg. 1-3.
Schmid, J.M., Mata, S.A., and Mitchell, J.C. 1986. Number
and Condition of Seeds in Ponderosa Pine Cones in Central Arizona.
Great Basin Naturalist, Vol. 46, pg. 449-451.
Schmid, J.M., Mitchell, J.C., and Mata, S.A. 1986.
Ponderosa Pine Conelet and Cone Mortality in Central Arizona. Great Basin Naturalist, Vol. 46, pg. 445-448.