Location: Southern Horticultural ResearchTitle: Integrating kaolin clay for ambrosia beetle (Coleoptera: Curculionidae: Scolytinae) management in ornamental tree nurseries Author
Submitted to: Journal of Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/4/2016
Publication Date: 1/1/2017
Citation: Werle, C.T., Addesso, K.M., Sampson, B.J., Oliver, J.B., Adamczyk Jr, J.J. 2017. Integrating kaolin clay for ambrosia beetle (Coleoptera: Curculionidae: Scolytinae) management in ornamental tree nurseries. Journal of Insect Science. 52(1):94-98. Interpretive Summary: Ambrosia beetles are an economic problem for nursery crop production, and available control measures are not adequately effective. We tested kaolin clay as an ambrosia beetle deterrent in MS and TN from 2014-15, as well as the industry-standard bifenthrin, a combination of kaolin + bifenthrin, and an untreated control. When combined with a surfactant, kaolin applications can contribute some additional deterrence to ambrosia beetles, but the effect is not dramatic and may not be cost-effective.
Technical Abstract: Abstract Invasive ambrosia beetles (Coleoptera: Curculionidae) are an important pest problem at ornamental tree nurseries. Available chemical measures are not completely effective, and due to the length of the beetle dispersal period and product breakdown, repeated treatments can become costly in terms of application expense and non-target impacts. Additional options are needed to reduce application frequency and to provide an acceptable level of protection. Four treatments were tested using baited trees at research sites in Mississippi and Tennessee in 2014-15, with the number of new ambrosia beetle galleries compared over time on 1) untreated control trees, 2) kaolin-treated trees, 3) bifenthrin-treated trees and 4) kaolin + bifenthrin-treated trees. Kaolin trees rapidly lost their coating after rain events, and after four days post-treatment, the number of beetle galleries was not significantly different between kaolin and untreated controls. Kaolin + bifenthrin trees retained their coating longer, but were not better-protected than bifenthrin trees. When combined with a pyrethroid containing a surfactant, kaolin applications can contribute some additional deterrence to ambrosia beetles, but the effect is not dramatic and may not be cost-effective. Further research is needed on the variety of other positive impacts kaolin applications may provide to ornamental tree production.