Author: Joseph D. Carillo

Invasive ambrosia beetles (Euwallacea spp.) commonly called shot hole borers (SHB) have been posing a threat to avocado groves as well as urban landscape and wildlands in California. Previous studies show that SHB tend to colonize primary, secondary and tertiary branches including branch collars of avocado. Therefore, effective management strategies for commercial avocado groves are limited to removal of infested branches to reduce beetle populations. However, some beetle galleries still remain around the branch collar which support future beetle reproduction and spread This investigation into pesticides for use in avocado against California invasive pest E. whitfordiodendrus commonly known as the polyphagous shot hole borer (PSHB) and FD indicate pesticide candidates have significant effectiveness against PSHB and their fungal symbionts in vitro and in field trials. The most effective treatment across all experimental trials was found to be the contact insecticide bifenthrin/ zeta-cypermethrin. Integrative pest management combining cultural management through phytosanitation along with chemical management can aid in reducing local PSHB populations within avocado groves, help reduce disease pressure and help prevent further spread within avocado groves as well as to other areas. 

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