Quick Facts

  • Mature larvae are 55-70 mm long and the 2nd and 3rd segments are marked with blue-black stripes
  • Female adult has wingspan of 60-80 mm, with an average body length of 39 mm
  • Male adult has wingspan of 40-60 mm, with an average body length of 31 mm
  • Color of the moths varies from light yellowish-brown or light gray to dark brown, almost black
  • Front wings are marked by two characteristic dark stripes
  • White spot is located at the center of front wing

Species Facts:

The Siberian Silk Moth, Dendrolimus superans sibiricus, is the most important defoliator of conifers (Siberian pine, larch, fir and spruce) in Russia and Kazakhstan (Rozhkov 1963, Epova and Pleshanov 1995, Vorontsov 1995), and one of the most important defoliators of larch in China (Yang and Gu 1995). Outbreaks can occur over many thousands of hectares and lead to the death of entire forests.

In its native range, the Siberian Silk Moth damages more than 20 species of trees in several genera including Pinus, Abies, Larix, Picea and Tsuga, which are widely distributed in North America. The Siberian Silk Moth also has a wide climatic range and is considered the most important pest of coniferous forests in Russia (from the center of European Russia to the Far East), Kazakhstan, Northern China, Korea and Northern Mongolia. There are 3 known subspecies of this pest, D. superans superans, which occurs only in Japan, D. superans albolineatus, which occurs on the Sakhalin and Kuril islands, and D. superans sibiricus, which is widespread on the Asian continent.

The evaluation made by Florov (1948) showed that during 90 years (1855-1945), the Siberian silk moth killed about 4 million hectares of Russian forests. According to Kolomiets (1958), during the 25-year period between 1932-1957, the Siberian silk moth damaged 7 million hectares of forests in Western Siberia and China alone, and caused the death of forests over half of this area. Similar data have been published by other scientists (e.g. Rozhkov 1963).

Outbreaks of the Siberian silk moth occur with a periodicity of 10 - 11 years (Rozhkov 1963, Epova and Pleshanov 1995, Vorontsov 1995) and are often preceded by two or three years of dry weather. Some scientists found that the cycle of these outbreaks coincide with the cycle of solar activity, and the maximum development of the outbreaks occurs in years of increasing number of sunspots (Galkin 1975, 1992).

Defoliation by Siberian silk moth causes death of forests over large areas, either directly or by leaving the forest susceptible to subsequent attack by other forest pests, and/or by predisposing the forest to forest fires (Rozhkov 1963, Mamaev 1990, Epova and Pleshanov 1995, Vorontsov 1995 ). Natural regeneration of these areas is often difficult and takes much time. Moreover, widespread use of biological and/or chemical insecticides for control of outbreaks can have undesirable effects on non-target species.

The defoliation usually lasts two or three years, which many trees are unable to withstand. Furthermore, the outbreaks of Siberian silk moth are also often followed by outbreaks of bark beetles and woodborers (Scolytidae, Cerambycidae and Buprestidae), particularly Ips typographus, I. subelongatus, Scolytus morawitzi (Scolytidae), Monochamus galloprovincialis, Xylotrechus altaicus (Cerambycidae), and Melanophila guttulata (Buprestidae) (Pavlovskii and Shtakelberg 1955, Rozhkov 1963, Mamaev 1990, Epova and Pleshanov 1995, Vorontsov 1995). These insects are able to kill trees weakened by defoliation caused by Siberian silk moth.

Portions of this article courtesy of: EXFOR Database
Siberiah Silk MothImage of a Siberian Silk Moth larva (Photo from: www.bugwood.org Credit to: John H. Ghent)