Kirichenko et al.: European conifers as host plants for neonate larvae of the Siberian Moth – a potential invasive species to Europe EUROPEAN CONIFERS AS HOST PLANTS FOR NEONATE LARVAE OF THE SIBERIAN MOTH – A POTENTIAL INVASIVE SPECIES TO EUROPE Natalia Kirichenko 1 , Stefan Vidal 2 , Yuri Baranchikov 3 1 V.N. Sukachev Institute of Forest SB RAS, Akademgorodok, 660036 Krasnoyarsk 1 (e-mail: nata_kirichenko@yahoo.co.uk) 2 (e-mail: svidal@gwdg.de) 3 (e-mail: baranchikov_yuri@yahoo.com) Abstract The performance of the Siberian moth Dendrolimus superans sibiricus Tschtvrk. was estimated on potential host trees from Central Europe on the basis of relative growth rates and survival of their first instar larvae. Larix decidua appeared to be the most suitable host, followed by Abies alba, Abies nordmannian, and Picea abies, respectively. The needles of Pinus silvestris and Pinus nigra proved to be poor substrates for larval development. A new potential host plant, Pseudotsuga menziesii, appeared to be highly favorable for the pest larvae. Keywords: Siberian moth, survival and growth of larvae, European coniferous species 1. Introduction The Siberian moth Dendrolimus superans sibiricus Tschtvrk. (Lepidoptera, Lasiocampidae) is the main pest of coniferous species in Northern Asia (Rozhkov 1963; Baranchikov et al. 1997). The moth dramatically damages thousands of hectares of forests (Baranchikov & Kondakov 1997). Weakened and stressed trees are subject to the attack of secondary pests, which finally results in forest death and its subsequent predisposition to fires (Furyaev 1966; Isaev et al. 1988). In its’ natural habitat, the Siberian moth feeds on coniferous species belonging to a few genera of the Pinaceae family, such as Larix, Abies, Pinus and Picea (Rozhkov 1963). The pest life cycle comprises two to three calendar years with the larvae overwintering once or twice. Eggs are laid by the end of June – the beginning of July and the larvae moult to the third or fourth instar before overwintering in the forest floor. They emerge in early spring and continue feeding extensively to complete their development in the same summer. However, the larvae may also enter into summer diapause and over-winter in the forth or fifth instar to complete their development during the third year (Baranchikov & Kirichenko 2002). The Siberian moth is distributed over a huge territory of Russia; it is now found from the coasts of the Okhotsk’ and the Japanse seas to the Urals (Rozhkov 1963). Recent records of the moth west of the Urals fuelled the hypothesis of its’ possible invasion into Europe in the near future (Gninenko & Orlinskii, 2002). Based on these recent records the species has been declared as a quarantine pest for EPPO-member countries (EPPO 2005; but see Baranchikov et al. 2006). However, so far there are no reports on the suitability of conifers from Central Europe for the Siberian moth (EPPO 2005). The data provided here will be useful to assess the invasion risk and prognosis of damage to European forests. In this study we evaluated whether European coniferous tree species could serve as host plants for the Siberian moth. Here we report on survival and growth rates of the first instar larvae of the pest on European conifers. Neonate larvae of several Lepidopteran species are the most sensitive to food quality IUFRO Working Party 7.03.10 Proceedings of the Workshop 2006, Gmunden/Austria 347