Project Overview
Annual Reports
Information Products
Commodities
- Fruits: grapes
Practices
- Pest Management: integrated pest management, traps
Proposal abstract:
The multicolored Asian lady beetle, Harmonia axyridis, has recently become an economically significant contaminant pest in the wine making process. H. axyridis adults tend to aggregate on clusters with injured berries just prior to harvest, and eventually may be incorporated with the grapes during wine processing. Once disturbed or crushed, H. axyridis, like most coccinellids, releases a yellow fluid in a process described as “reflex bleeding”. The fluid from reflex bleeding contains alkaloids used for defense, and alkyl-methoxypyrazines (Al Abassi et al. 1998). One alkyl-methoxypyrazine, 2-isopropyl-3-methoxypyrazine (IPMP), has been identified as one of the key compounds responsible for affecting wine flavor after H. axyridis has been crushed with the grapes during the wine processing. The alkyl-methoxypyrazines have also been related to the aggregation behavior of H. axyridis as well as other lady beetles during fall.
Current management of this pest relies on chemical control and mechanical removal of beetles from clusters by floating grapes in water, vacuuming, or manually picking beetles from grapes (Galvan et al. 2006c). Remediation procedures to remove or decrease the H. axyridis-related taint from the wine were tested, but none of them showed satisfactory results. In addition, the sensory threshold of H. axyridis off-flavor in wine ranges from 0.1 to 0.4 beetles per cluster (Galvan et al. 2007b). Such a low threshold and the paucity of management programs demonstrate the potential damage that this pest could cause to the wine industry in U.S. states and Canadian provinces in the Great Lakes region. With this proposal, we present a novel “push-pull” strategy to address the MALB problem, without the use of conventional insecticides.
Project objectives from proposal:
1) Four-arm olfactometer to complete identification of most active attractants and repellents to H. axyridis under laboratory conditions (preliminary data for 6 compounds complete).
2) Determine retention times (i.e., half-life) of candidate semiochemicals used for attractants and repellants placed on sticky traps under field conditions.
3) Field assessment and efficacy of candidate “pull”-attractants (based on those found to be most efficacious from laboratory studies), using sticky cards (e.g. Galvan et al. 2006). This will be done at the Rosemount, UofM Agric. Experiment Station (UMORE Park), near soybean fields.
4 In-field “push”-repellent studies to assess if volatiles can effectively repel H. axyridis.
5)— Combine the best push-pull compounds into a complete IPM program in vineyards.