Weather

    Georgia Pecans: Ambrosia Beetles Now Active

    Signs of active ambrosia beetles on pecan tree. Photo: University of Georgia

    I’ve talked to growers from Fort Valley to South Georgia who have identified Ambrosia beetles now active. This week’s warm weather is the perfect conditions for adults to start flying. If you have had problems with this pest before OR if you have newly planted trees, it is likely a good idea to begin spraying the trunks of young (1-3 yr old) trees with a pyrethroid like Bifenthrin.

    Due to the number of beetles captured inside trunk protectors, make sure to remove the protectors before spraying OR spray down into the tube, being sure to coat the trunk as best you can.

    The last two years, former entomologist Dr. Angel Acebes organized research on ambrosia beetle control. Initially, we were looking at painting the trunks of trees compared to spraying a pyrethroid. I managed one of the locations in 2020, and that year we found the best control was both 1) spraying pyrethroid right after painting the trunk with white latex paint and/or 2) spraying pyrethroid onto the trunk once a week.

    This experiment was conducted again in 2021 where spraying pyrethroid was better than everything else.

    Table 1: The control logs, Entomopathogenic fungi, trunk protectors and painted only logs were statistically all the same. Spraying pyrethroid every week was better than the paint with the pyrethroid together. Click Image to Enlarge

    Considerations and Plan for Management

    • Newly planted trees through 3 years of age
    • Trees closest to the wooded areas (maybe three rows in).
    • Set Ambrosia Beetle traps. Even though beetles are now flying does not mean your orchard will have high numbers.
    • Scout for small holes or ‘toothpicks’ / sawdust from the logs. There are many species of ambrosia beetles and other small beetles, but this species leaves behind the sawdust.
    • Hand sprayer, shotgun approach is the best method of control. Once beetle activity is confirmed, scout your trees. 1 oz of a pyrethroid in 10 gallons of water is sufficient. Because attacks occur down in the herbicide guards, an airblast sprayer is not recommended.
    • Spray every 10 days to 2 weeks. A pyrethroid has residual for a short time. If it rains following an application, consider the insecticide no longer active.
    • Monitor traps now through May (below). This species of ambrosia beetle is not very active once we reach summer.

    Table 2. Trapping reveals flights of adult beetles beginning early spring, generally followed by a flight in late spring before they cease. Click Image to Enlarge




    The Latest


    Send press releases to Ernst@Agfax.com.

    View All Events


    Send press releases to Ernst@Agfax.com.

    View All Events

    Weather