Options for control of scolytid beetles that attack pines.

Abstract Scolytid beetles (Coleoptera: Curculionidae: Scolytinae) are a large group of beetles associated with many tree species. Some species consume dead wood and vector an array of fungi which contribute to recycling of organic material, so are often an important component of forest ecology. However, populations can increase to pest levels. In this review, we look at options for control of scolytid pests of Pinus spp. Pines, valued for their softwood and pulp, are grown commercially in many countries. Both indigenous and exotic species of bark beetle are pests of pines. There have been numerous approaches to reducing the impact of bark beetle attack on pines. Management strategies have included thinning stands and timing of harvesting and planting, through to efforts to predict outbreaks. Bark beetles use semiochemicals to locate hosts and attract conspecifics and these have been used to trap or repel beetles, or disrupt their behaviour. Chemical pesticides have been used, especially for protection of high-value trees. Pesticides can be effective in some situations, but the commonly used actives such as organophosphates and pyrethroids have non-target and other health and safety concerns. There have been few successful introductions or applications of natural enemies (predators, parasitoids and microbial pathogens) reported for scolytid pests of pines. The cryptic, within-tree, habitats used for much of the bark beetle life cycle provide significant protection against most forms of control. Successful control will require novel approaches and will likely involve multiple agents and strategies.