Suitability ofCalifornia bay laurel and other species as hosts for the non‐native redbay ambrosia beetle and granulate ambrosia beetle

Abstract

AbstractThe redbay ambrosia beetleXyleborus glabratusEichhoff is a non‐native vector of the pathogen that causes laurel wilt, a deadly disease of trees in the familyLauraceae in the southeasternU.S.A.Concern exists thatX. glabratusand its fungal symbiont could be transported to the westernU.S.A. and cause damage toCalifornia bay laurelUmbellularia californica(Hook. &Arn.)Nutt. inCalifornia andWashington.The present study evaluated in‐flight attraction, attack density and emergence ofX. glabratusand another invasive ambrosia beetleXylosandrus crassiusculus(Motschulsky) on cut bolts ofCalifornia bay laurel and eight related tree species in an infested forest inSouthCarolina.Xylosandrus crassiusculusis not a vector of the laurel wilt pathogen but is a pest of nursery and ornamental trees.Mean catch ofX. glabratusonCalifornia bay laurel bolts was not significantly different from catches on bolts of knownX. glabratushosts sassafrasSassafras albidum(Nutt.)Nees and swampbayPersea palustris(Raf.)Sarg. Mean attack density and adult emergence of both beetle species fromCalifornia bay laurel was equal to or greater than all other tree species tested. Both beetle species readily produced brood inCalifornia bay laurel bolts.The results obtained in the present study suggest thatCalifornia bay laurel may be negatively impacted by both of these invasive ambrosia beetles if they become established in the tree's native range.