Interception Strategies for Managing Exotic Ambrosia Beetles (Coleoptera: Curculionidae) in Nurseries

Exotic ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) cause considerable damage in ornamental tree nurseries and other tree crops in North America. Ambrosia beetles bore into the xylem of trees to establish gardens of symbiotic fungi, which are the source of nutrition for adults and larvae (Wood 1982, Great Basin Nat. Memoirs. 6: 1–1359). Establishment of fungal gardens is crucial as some species of ambrosia beetles delay oviposition until their symbiotic fungi are growing (French and Roeper 1972, Can. Entomol. 104: 1635–1641; Weber and McPherson 1983, Ann. Entomol. Soc. Amer. 76: 455–462; Peer and Taborsky 2005, Evolution 59: 317–323). Colonization of nursery trees by ambrosia beetles often leads to wilting, stem dieback, or death (Ranger et al. 2016, J. Int. Pest Manag. 7: 1–23). Nursery growers rely on preventive trunk sprays of insecticides to protect trees from ambrosia beetles. However, insecticide sprays were inconsistent at preventing colonization attempts by ambrosia beetles in previous research (Frank and Sadoff 2011, J. Econ. Entomol. 104: 196