Additional host range testing of Eucryptorrhynchus brandti (Coleoptera: Curculionidae) for the biological control of tree-of-heaven, Ailanthus altissima (Simaroubaceae) in the U.S.A.

Abstract

ABSTRACT Ailanthus altissima, native to China, is a highly invasive plant in North America, Europe, and other continents. This species displaces native plants by forming dense clonal thickets. Ailanthus altissima is shade intolerant, quickly invades fields, rights-of-way, urban areas, and areas in forests disturbed by logging, fire, or pests. This species is also a primary host of the economically damaging spotted lanternfly, Lycorma delicatula, recently introduced into the U.S. Eucryptorrhynchus brandti is native to China and has been identified as a potential biological control agent of A. altissima. Oviposition studies conducted on 11 non-target plant species demonstrated that E. brandti oviposited only on the U.S. native Leitneria floridana. All non- Leitneria species had adult feeding of less than 2% compared to A. altissima, with no oviposition or larval development. Longevity of E. brandti in no-choice tests with L. floridana and L. pilosa subsp. ozarkana, was shorter and the weevils consumed less foliage compared to A. altissima. Seventeen percent of the L. floridana trees tested had larval feeding and 18 E. brandti adults emerged from 10 replicates. No L. floridana trees with larval feeding died. All the A. altissima trees with larval development died. Eucryptorrhynchus brandti is projected to be an effective agent against A. altissima and pose no significant risk to native North American plant species, with potential to be an additional management tool for the spotted lanternfly.