Efficacy of Two Systemic Insecticides Injected Into Loblolly Pine for Protection Against Southern Pine Bark Beetles (Coleoptera: Curculionidae)

Abstract

We evaluated the efficacy of systemic insecticides emamectin benzoate and fipronil for preventing mortality of individual loblolly pines, Pinus taeda L., as a result of attacks by southern pine bark beetles (Coleoptera: Curculionidae, Scolytinae) for two consecutive years in Mississippi (2005-2006) and Alabama (2006-2007). Trees were injected once in the spring of 2005 (Mississippi) or 2006 (Alabama) and then were baited with species-specific bark beetle lures several weeks later. The southern pine beetle, Dendroctonus frontalis Zimmermann, was the target species but was changed to Ips spp. in Mississippi (but not Alabama) the second year because of few southern pine beetle attacks on baited trees. Single injections of emamectin benzoate were effective in reducing tree mortality caused by bark beetles compared with untreated checks. Although less effective overall, fipronil also significantly reduced tree mortality from southern pine beetle compared with the checks during the second year in Alabama. Tree mortality continued well after the lures had been removed. Evaluations of bolts taken from experimental trees killed in 2006 indicated that emamectin benzoate effectively prevented parent bark beetle gallery construction and that fipronil significantly reduced lengths of galleries constructed by adult beetles, brood development, and emergence, compared with checks. In contrast, neither insecticide treatment prevented the bark beetles from inoculating blue stain fungi, Ophiostoma spp., into treated trees.

Use of Systemic Fipronil and Imidacloprid to Control Regeneration Pests of Loblolly Pine

“…Further studies are needed to determine the most effective way to maximize uptake of systemic Þpronil by newly planted pine seedlings. New systemic insecticide formulations continue to show promising results for controlling a variety of pests of southern pines such as seed and cone insects (Grosman et al 2002), wood borers (Grosman and Upton 2006), and pine bark beetles (Grosman et al 2009). In addition to Nantucket pine tip moth control, our data also suggest that both Þpronil and imidacloprid protect against damage from pales weevil, although more much more extensive testing is needed to adequately demonstrate this.…”

Volatile Organic Compounds Emitted by Fungal Associates of Conifer Bark Beetles and their Potential in Bark Beetle Control

“…However, accessibility to remote areas and economic and environmental constraints often hamper quick removal of large numbers of infested trees (Christiansen and Bakke 1988). Usage of insecticides that specifically target beetle species is another straightforward control strategy that can cause severe mortality to broods at the site of treatment (Grosman et al 2009). However, insecticides can play at most a relatively small role in managing major outbreaks due to the logistics and economics of applying insecticides over large, remote forested areas.…”

Impact of the goldspotted oak borer, Agrilus auroguttatus, on the health of coast live oak before and after treatment with two systemic insecticides

“…Finally, the absence of a strong attractant for A. auroguttatus limits our ability to manipulate attack rates on experimental trees, which has been a useful technique with other subcortical insects. For instance, in studies of the efficacy of insecticides (including EB) for the control of conifer bark beetles, aggregation pheromones are used routinely to challenge the experimental trees …”