Phenological observations and trapping tactics for the granulate ambrosia beetle Xylosandrus crassiusculus (Coleoptera: Curculionidae, Scolytinae) in New Zealand

Authors: SUTHERLAND, ROANNE - Department Of Conservation; MEURISSE, NICOLAS - Department Of Conservation; PUGH, ANDREW - Department Of Conservation; Ranger, Christopher; Reding, Michael - Mike; KERR, JESSICA - Department Of Conservation; RUSSELL, JESSICA - Ministry For Primary Industries; WITHERS, TONI - (NCE, CECR)networks Of Centres Of Exellence Of Canada, Centres Of Excellence For Commercilization A

Submitted to: Agricultural and Forest Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/23/2022
Publication Date: 1/24/2023
Citation: Sutherland, R., Meurisse, N., Pugh, A., Ranger, C.M., Reding, M.E., Kerr, J., Russell, J., Withers, T. 2023. Phenological observations and trapping tactics for the granulate ambrosia beetle Xylosandrus crassiusculus (Coleoptera: Curculionidae, Scolytinae) in New Zealand. Agricultural and Forest Entomology. 25(3): 355-364. https://doi.org/10.1111/afe.12558.
DOI: https://doi.org/10.1111/afe.12558

Interpretive Summary: The invasive ambrosia beetle Xylosandrus crassiusculus (granulate ambrosia beetle, GAB) was discovered in New Zealand in 2019. Research was initiated to test methods for monitoring and determine its seasonal activity. Flight interception traps baited with ethanol and ethanol-soaked sections of tree stems (bolts) were tested for monitoring GAB flight activity. Monitoring was conducted during October through April, the spring and summer seasons in New Zealand. The research indicated that GAB was most active during November and December, while 99% of the flight activity was completed by mid-February. Traps baited with lures releasing 2gm of ethanol per day were most attractive to GAB. However, ethanol-soaked bolts and traps baited with lower release ethanol lures were also attractive, they just did not capture as many beetles as the high-release ethanol baited traps.

Technical Abstract: ylosandrus crassiusculus is one of the most damaging exotic ambrosia beetle pests in North American ornamental plant nurseries. It has recently established in New Zealand. Like most ambrosia beetles X. crassiusculus is polyphagous and was discovered attacking numerous species of broadleaf trees in the Auckland region. We initiated flight intercept trapping with ethanol release lures at three infested sites to ascertain the phenology of the pest in New Zealand. At least two peak flight periods were identified in early and in late summer, and a smaller peak in some cases in early Autumn. One site showed consistently high populations and was used to test a wider range of trapping methods. The various methods included ethanol-soaked or unsoaked wood bolts from three species of trees and flight intercept trap baited with three ethanol lures of various release rates. Wood bolts and traps were emptied every two weeks. The most successful lure at capturing X. crassiusculus was releasing 2 gm ethanol /per day from the thick plastic lure with a hole punched in the top. The most infestations were achieved within hanging bolts was using ethanol-soaked bolts of Taiwan cherry (Prunus campanulata) ethanol-soaked wood bolts. This pest carries a significant risk for broadleaf native species of shrubs and trees, as well as exotic productive trees within both the horticultural and forestry sectors in New Zealand. We recommend ethanol baited lures in panel traps as an effective tool for tracking its spread.