- Fruits: grapes
- Education and Training: extension, on-farm/ranch research
- Pest Management: biorational pesticides, chemical control, cultural control, field monitoring/scouting, integrated pest management, row covers (for pests), traps
- Production Systems: agroecosystems
This research provided significant contributions to our knowledge of the Harmonia axyridis-wine grape system. Adult beetles feeding on wine grapes appeared to increase their overwintering survival. Also, yellow jackets and beetles were not able to break the skins of grape berries directly. For growers, we developed practical sampling plans based on six potential action thresholds. We also examined the efficacy of biorational and conventional insecticides for managing H. axyridis. The combination of a sampling plan and the use of effective insecticides proved useful to growers in 2005; both will be essential components of sustainable management plans for this new pest.
The multicolored Asian lady beetle, Harmonia axyridis (Pallas) has become a significant pest of fall ripening fruit in Minnesota and the Midwestern U.S., including infestations in grapes. Live or dead beetles, crushed with grapes during the wine making process, create an unpleasant odor and taste. Economic consequences of this pest include complete losses to growers, or increased costs from additional time and labor needed to wash and process grapes before juicing. Given the potential for continuing economic impacts by this pest, and a lack of research-based management alternatives, this project will assess new approaches to minimize beetle infestations and guidelines to reduce insecticide use. Project outcomes, including the use of on-farm research and rapid web-based delivery methods, will increase grower awareness regarding new management tactics, including the potential for floating row covers, chemical control, and the possibility of using trap cropping to attract and kill beetles outside of the primary vineyard. In addition, this project will explore possible reasons for H. axyridis feeding on ripening grapes and the role of wasps in this process.
Project objectives:div style="margin-left:1em;">
1 — Evaluate floating row cover barriers to exclude H. axyridis from grapes near ripening.
This objective will compare the efficacy of row cover in protecting grapes from H. axyridis with the efficacy of insecticides and an untreated check. To be a practical management tactic, the mesh must not alter the quality of grapes for wine production. Potential negative effects from shade induced by the row cover will be evaluated through measuring sugar, pH and time to ripening of grapes.
2 — Spatial distribution of H. axyridis infestations in vineyards.
This objective will evaluate the spatial distribution of H. axyridis in vineyards, and develop a sampling plan for H. axyridis in wine grapes.
3 — Biological impetus and mechanisms for H. axyridis feeding on fall ripening grapes.
This objective will determine how H. axyridis utilizes simple sugars obtained from grapes. Sub-objective 3A evaluate the survival of males and females of H. axyridis adults after feed on a 25% sucrose solution, fresh squeezed grape juice, or water alone for 48 h. Sub-objective 3B will determine the amounts of body sugars and lipids of males and females of H. axyridis adults after feed on the aforementioned diets.
4 — Interaction among H. axyridis, wasps, and grapes: source of initial fruit damage?
This objective will determine if wasps cause direct damage that subsequently allows H. axyridis feeding.