Natality, mortality and control of the elm bark beetle Scolytus scolytus (F.) (Col., Scolytidae)

Abstract

Natality is more important than mortality in the determination of the number of first-generation adults of Scolytus scolytus (F.) to emerge. The reverse is the case for the overwintering generation. Temperature is a probable key factor for the first generation, and subcortical predators for the overwintering generation. These results are related to possible control of the beetle as a vector of Dutch elm disease by injection of systemic insecticides. It is suggested that control measures may only be necessary in the climatic conditions of the United Kingdom in hot summers when a large first generation is likely to emerge. Natural mortality factors will effectively reduce the beetle population that overwinters.