A novel method for controlling multicolored Asian lady beetle (Coleoptera: Coccinellidae) in vineyards.

The introduced biological control agent Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) has attained pest status in North America as its presence in vineyards during harvest may compromise the quality of the resulting wine. Control of H. axyridis in vineyards is difficult as their populations may fluctuate daily, and there are few products registered to control this pest. Sulfur dioxide, in the form of potassium metabisulfite (KMS), is commonly used in wine as both an antimicrobial and an antioxidant. In this study, the effectiveness of KMS as a repellent against H. axyridis was measured. In a Y-tube olfactometer, H. axyridis spent significantly less time in the treatment arm (KMS 2.5, 5, and 10 g/liter) than in the control arm during a 10-min period. When sprayed in a vineyard, KMS significantly reduced the number of H. axyridis on grape vines. KMS is an effective repellent against H. axyridis and may be suitable for use in vineyards to control this pest. KMS (5 g/liter) applied to Riesling grapes at 2 wk, 1 wk, 3 d, or 1 d before harvest did not affect free sulfur dioxide in either freshly processed or settled juice. This study lays the foundation for the development of a pest management strategy incorporating repellents for H. axyridis in vineyards.