Contributions to the knowledge on biology and phenology of Cryphalus piceae (Coleoptera: Curculionidae: Scolytinae)

The small fir bark beetle (Cryphalus piceae) was discovered in Denmark in 2012. Since then, several local outbreaks in greenery plantations have occurred, with numerous dead Noble firs (Abies procera) reported. The aim of this study was to investigate the life cycle and behavioral patterns of C. piceae in Denmark, compared with a literature review of the general life cycle. Currently, C. piceae has been recorded from 24 plantations spread across Denmark. Experimental results confirm the possibility of two complete generations a year plus pertaining sister generation. Cryphalus piceae is generally considered a secondary bark beetle, and in Denmark it was mainly associated with Heterobasidion infected trees. However, its ability to overwinter in living healthy trees makes it a potential vector of unwanted diseases and therefore preventive control methods could be desired. Based on the life cycle, a yearly sanitary cutting in either mid-May or mid-June is recommended, as a control method against C. piceae in monocultures. In Danish greenery plantations, preventive measures against Heterobasidion were evaluated as the most important factor to avoid dead A. procera and the pertaining high populations of C. piceae.