Predators of the Southern Pine BeetleThis article is part of a larger document. View the larger document here.
This chapter of the Southern Pine Beetle II reviews the overall influence of predators on southern pine beetle (SPB) population dynamics, as well as recent research on specific predators such as the clerid beetle Thanasimus dubius. Several lines of evidence suggest that predators and other natural enemies generate significant SPB mortality that contributes to outbreak collapse, likely operating with a time delay and so causing delayed density-dependence. The predators that seem most likely to significantly impact SPB are T. dubius, the dolichopodid fly Medetera bistriata, and several woodpecker species. The chemical ecology of both T. dubius and M. bistriata indicates they are well synchronized with mass attack by SPB. The prolonged development of T. dubius under field conditions, however, suggests it is a component of the delayed density-dependence seen in SPB. It is recommended that trees vacated by SPB be left intact during control operations because these often contain immature T. dubius 1-2 years after SPB attack, and also provide foraging and nesting opportunities for woodpeckers. Current research is exploring methods for mass-rearing T. dubius using an artificial diet, for potential use as a control tactic.