Distribution, Pest Status and Fungal Associates of Euwallacea nr. fornicatus in Florida Avocado Groves.

Members of a complex of cryptic species, that correspond morphologically to the ambrosia beetle (Eichhoff) (Coleoptera: Curculionidae: Scolytinae), were recently found attacking avocado ( Mill.) in Israel and California. In early 2016, an outbreak of another member of this species complex was detected infesting approximately 1500 avocado trees in an avocado orchard at Homestead, Florida. An area-wide survey was conducted in commercial avocado groves of Miami-Dade County, Florida to determine the distribution and abundance of nr. , to identify different populations of nr. and their fungal associates, and to assess the extent of damage to avocado trees. nr. were captured in 31 of the 33 sampled sites. A sample of 35 beetles from six different locations was identified as . nr. sp. #2, which is genetically distinct from the species causing damage in California and Israel. Eleven fungal associates were identified: an unknown sp., AF-8, AF-6, sp. , , sp. and three yeast species. The unknown isolates were the most abundant and frequently found fungus species associated with adult beetles and lesions surrounding the beetle galleries. In addition to fungal associates, three bacteria species were found associated with adult nr. . Visual inspections detected significant damage in only two orchards. A large number of beetles were captured in locations with no apparent damage on the avocado trees suggesting that nr. are associated with other host(s) outside the groves or with dead trees or branches inside the groves. More research is needed to determine the potential threat nr. and its fungal associates pose to the avocado industry and agricultural and natural ecosystems in Florida.