Flight period and ecology of Trypodendron proximum (Niijima) (Col., Scolytidae) in Finland

The flight period of Trypodendron proximum was studied by pheromone-baited window traps in three localities in Finland. Trypodendron proximum started to fly at + 13 degrees C, and swarming peaked at around +15 degrees C, whic h was the threshold temperature for the flight of Trypodendron lineatum. Th ere was only a little overlap in the flight periods of T. proximum and othe r Trypodendron species. Trypodendron proximum constituted 4.5-22.1% of the total number of Trypodendron individuals caught. Field observations indicat ed that T. proximum may overwinter in the bark of standing trees, which wou ld enable the beetles to fly when there is still snow. Most of the field ob servations of T. proximum are from dead standing Norway spruces and Scots p ines in Finland.