Situation of Ips duplicatus in the Czech Republic
Until the beginning of the 20th century, Ips duplicatus (Curculionidae, Scolytinae - EU Annexes) occurred only in the Euro-Siberian taiga from Sweden to the Sakhalin Island and in the Alps. During the subsequent decades the pest has expanded its range to Central Europe (e.g. Czech Republic, Poland, and Slovakia). In the Czech Republic, the insect was first recorded in the 1920s and outbreaks have been reported since the 1970s in the North-East. Monitoring surveys with pheromone traps were carried out from 1997 to 2009 in state forests and showed that I. duplicatus now occurs practically across the whole territory of the Czech Republic, mainly on spruce (Picea abies). The numbers of insects caught fluctuated over time (low populations were observed in 2002 and a peak was observed in 2008). Insect populations were higher in the North-Eastern and Eastern parts of the country (Northern Moravia and Silesia) where I. duplicatus was first recorded but observations showed that it is currently spreading towards the South and West. In the North-Eastern parts of Czech Republic up to 80% of the spruce trees which had been felled for sanitary reason were infested by I. duplicatus. However, it is acknowledged that several factors are involved in spruce decline, including low soil pH, nutrient deficiency, drought, infections by Armillaria ostoyae and bark beetles. In the South and West parts of the country where populations of I. duplicatus were lower, no economically significant damage was observed.
The situation of Ips duplicatus in the Czech Republic can be described as follows: Present, mainly in the north-eastern and eastern parts on Picea abies but spreading towards the south and west.
Holuša J, Grodzki W (2008) Occurrence of Ips duplicatus (Coleoptera: Curculionidae, Scolytinae) on pines (Pinus sp.) in the Czech Republic and southern Poland – Short Communication. Journal of Forest Science 54(5), 234–236.
Holuša J, Lubojacky J, Knizek M (2010) Distribution of the double-spined spruce bark beetle in the Czech Republic: spreading in 1997-2009. Phytoparasitica 38(5), 435-443.