Diversity of Scolytinae (Coleoptera: Curculionidae) Attracted to Avocado, Lychee, and Essential Oil Lures

Abstract

The redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), is an exotic wood-boring insect that vectors laurel wilt, a lethal vascular disease of trees in the Lauraceae, including avocado (Persea americana) and native Persea species (redbay, swampbay). As part of research to identify host-based attractants for X. glabratus, we discovered that a diverse array of non-target ambrosia beetles was attracted to the same substrates as X. glabratus. During Sep–Dec 2009, several field tests were conducted in north Florida (in woodlands with advanced stages of laurel wilt) with traps baited with commercial lures of the essential oils, manuka and phoebe, and with freshly-cut wood bolts of avocado (a known host) and lychee (Litchi chinensis, a non-host high in the sesquiterpene αcopaene, a putative host attractant). In addition, manuka-baited traps were deployed in avocado groves in south Florida to monitor for potential spread of X. glabratus. The combined trapping results indicated that none of these substrates was specific in attraction of X. glabratus. Numerous non-target ambrosia beetles were captured, including 17 species representative of 4 tribes within the subfamily Scolytinae. This report provides photo-documentation and data on the species diversity and relative abundance for a group of poorly-studied beetles, the scolytine community in Florida Persea habitats.