Ambro Repel: A semiochemical repellent for invasive ambrosia beetles

USDA SBIR Phase II-FY21-Title: Ambro Repel: A semiochemical repellent for invasive ambrosia beetles.COMPANY: ISCA TECHNOLOGIES INC. PI: DR. MAFRA-NETOField 7. Project Summary/AbstractThis Phase II project will provide an effective repellent to control multiple invasive ambrosiabeetle pests of forestry and agriculture. Ambrosia beetles are closely related to bark beetles andshare many of the same behaviors digging galleries into the wood of trees in which to lay eggsand rear their young. Unlike bark beetles ambrosia beetles do not feed directly on the tree's tissuesbut instead use them as substrates to cultivate ambrosia fungi which they rely on for sustenance.Redbay ambrosia beetle (Xyleborus glabratus) is a key pest of redbay trees (Persea borbonia) andother lauraceous plants and transmits the deadly fungal pathogen laurel wilt Raffaelea lauricola.This disease has devastated the forest ecosystems of the southeastern US killing over half a billiontrees since RAB was first detected in Georgia in 2002 and is a serious threat to the Florida avocadoindustry. Black stem borer (Xylosandrus germanus) has become a major pest of ornamental treenurseries and landscapes across the US transmitting its associated fungus Ambrosiella hartigiiand the pathogenic Fusarium spp. which can damage timber and cause stem cankers dieback andin some cases tree death. The polyphagous shot hole borer has recently emerged as a serious threatto multiple tree species in California through transmission of Fusarium dieback which interfereswith the conduction of food and water through the tree placing it under stress and eventuallyleading to dieback. Current control techniques for ambrosia beetles are limited consisting ofkeeping trees as healthy as possible to minimize their susceptibility to attacking beetles and fungalinfection. Conventional pesticide treatments have generally not been effective against these pests.ISCA proposes to develop a new control product to meet this challenge: Ambro Repel a potentrepellent that will prevent attack on vulnerable forest and crop trees by ambrosia beetles. Thisproduct will combine naturally occurring repellent compounds such as the anti-aggregationpheromone verbenone and the plant-produced volatile methyl salicylate (MeSa) with ISCA's® controlled-released matrix SPLAT (Specialized Pheromone & Lure Application Technology) toproduce a formulation that will provide effective long-lasting protection of treated trees and smallstands and will also be amenable to quick inexpensive application via a range of manual andmechanized application equipment. Ambro Repel would allow forestry personnel landscapersand farmers to efficiently promote area-wide control to eradicate new invasive populations controlestablished populations and slow the spread of ambrosia beetles to new areas without resorting toadditional inputs of environmentally hazardous resistance-prone conventional pesticides.Phase I of this project produced excellent results: Several Ambro Repel prototypes containingverbenone MeSa or both have shown efficacy in reducing trap captures and/or number of attackson susceptible trees by seven species of ambrosia beetles (black stem borer Cnestus mutilatusXylosandrus crassiusculus redbay ambrosia beetle polyphagous shot hole borer Xyleborusvolvulus and X. bispinatus) in both forestry (Florida redbay groves) and agricultural settings(avocado groves potted apple trees). Phase II studies will build on these successes by conductingadditional formulation work to extend the field life of Ambro Repel from <21 days (observed inPI studies) to 3 months and expand the product's range of repellency to enable a more cost- effective application strategy. Optimized Ambro Repel prototypes will then be subjected to a seriesof field trials to identify repellent's optimal application strategy for orchards and nurseries an