Influence of acetic acid on attraction and colonization of wood bolts by ambrosia beetles (Coleoptera: Curculionidae: Scolytinae)

Authors: Reding, Michael; Ranger, Christopher; Baniszewski, Julie

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/24/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: nvasive ambrosia beetles damage tree crops in North America. We are still trying to determine physiological conditions of trees that make them attractive and vulnerable to attacks by ambrosia beetles. Flooding conditions can lead to production of ethanol by trees, which attracts ambrosia beetles. However, there may be other factors involved in whether ambrosia beetles can successfully colonize trees. Some research suggests pH may play a factor. Furthermore, acetic acid occurs with ethanol in trees exposed to flooded conditions. We tested combinations of ethanol and acetic acid in wood bolts (tree stem sections) to determine attraction and colonization success by the most damaging ambrosia beetles in Ohio. The combination of ethanol and acetic acid was more attractive to damaging ambrosia beetles than either material alone; and colonization was more likely in bolts soaked in combinations of acetic acid and ethanol than either compound alone. Adding acetic acid to ethanol for baits should make monitoring in tree crops more efficient. This will enable growers to detect damaging ambrosia beetles at lower activity levels, which will give growers a better early warning system for timing their control treatments.

Technical Abstract: Certain invasive ambrosia beetles are attracted to and colonize physiologically stressed trees emitting ethanol. Acetic acid has been found in stressed trees emitting ethanol, but its role in ambrosia beetle ecology is unknown. Sections of tree stems (bolts) were soaked in various dilutions of acetic acid alone and mixed with a 5% dilution of ethanol, then deployed in a field near a woodland. Bolts soaked in 5% or 10% dilutions of acetic acid were more attractive to Xylosandrus germanus (Blandford) and Xylosandrus crassiusculus (Motschulsky) than bolts soaked in dilutions of 0.1 or 1.0%. Dilutions of acetic acid mixed with 5% ethanol were more attractive to X. germanus and X. crassiusculus than acetic acid alone or ethanol alone, regardless of acetic acid dilution. Furthermore, more offspring were produced in bolts soaked in mixtures of acetic acid + ethanol than either compound alone. This information helps improve our knowledge of the physiological conditions in trees that make them suitable for colonization by X. germanus and X. crassiusculus. Furthermore, the increased attraction of damaging ambrosia beetles to acetic acid + ethanol could be useful for developing improved baits used in traps for monitoring emergence of X. germanus and X. crassiusculus in spring.