New Pest Response Guidelines - aphis - US Department of Agriculture

Pest Information
Dendrolimus sibiricus
SSM is the most devastating defoliator pest of coniferous forests in Russia,
China, Mongolia and Kazakhstan where it feeds primarily on Pinus sibirica,
Larix sibirica, Abies sibirica, Picea obovata, Larix cajanderi (in Russia and
Kazakhstan) and Larix gmelinii (in China) (Averensky et al., 2010; CABI,
2011a; EPPO, 2005). Periodical outbreaks results in the death of millions of
trees over extensive areas and may last up to 12 years (Averensky et al., 2010 ).
In Russia, trees covering an estimated area of 14.67 million ha were killed by
extensive SSM defoliation between 1990 and 2001 with the outbreak of 2000-
2001 being one of the most devastating (13.11 million ha). By comparison
damages were estimated at 116,000 ha from PTL and 9.76 million ha from
Lymantria dispar, the Gypsy moth, over the same time period (Mozolevskaya
et al., 2002a). In Siberia, ten outbreaks have been recorded since 1873 of
which the last five (over the period of 1935 to 1997) have resulted in the
defoliation and death of trees in an estimated area of 5.40 million ha
(Baranchikov, 1997 ). In Yakutia, eight outbreaks have been reported from
1948 to 1999 resulting in 870,000 ha of Larix forests defoliated (Averensky et
al., 2010 ). During the period of 1980 to 1990 it was estimated that 15 million
m 3 of wood were lost in Siberian forests due to SSM damage (Shvidenko et al.,
1998 ). Outbreaks in Mongolia have been equally devastating. In the Khan
Khentii and Bogd regions an estimated one million ha of larch and pine forest
were severely damaged by SSM (Ghent and Onken, 2003 ). In Jilin province in
China, 13 million trees were lost due to extensive defoliation in 1953 alone
(Liu and Shih, 1957).
Affected trees die during extensive periods of outbreaks lasting several years.
However, certain species, most notably Larix cajanderi can tolerate heavy
infestations better than other species (For example pines, fir and spruce)
because of their high capacity to regenerate leaves. Larix cajanderi can tolerate
50-70% defoliation during two consecutive seasons and trees can fully recover
from the damage in a few years thus, facilitating the recovery of the forest and
the ecosystem (Averensky et al., 2010 ).
2-40 Dendrolimus Pine Moths 12/2012-01