Fight the Mite! Post-harvest Control of Eriophyid Mites in Garlic

View the project final report

Commodities

• Vegetables: garlic

Practices

• Pest Management: biological control

The eriophyid mite Aceria tulipiae, commonly known as dry bulb mite, has been documented in garlic crops in the United States since 1938 and causes worldwide average losses of 23%. In the northeast extension specialists have documented economic losses for the last five years with increasing frequency, and it is assumed that distribution of dry bulb mites is widespread. Garlic is an economically important crop, estimated at a value of $55 million annually in New York. While New York is the dominant seed producing state of the northeast, growers in Vermont and Maine are expanding production and are distributing through regional seed companies. 

Dry bulb mites cause significant damage to garlic crops in storage and in the subsequent growing season.  In storage each generation takes just 8-10 days to develop at room temperature. Heavily infested garlic that is replanted may die from secondary diseases over the winter or may emerge with stunted, twisted, and yellowed foliage resembling viral infection. Garlic often grows through minor infections but may harbor enough mites through the season to start the cycle again in storage. 

Research is ongoing to assess treatments to suppress mites during the growing season and during drying and storage storage.  We know that sometimes a few mites survive all currently used treatments, and we propose the novel approach of  applying predatory Stratiolaelaps mites at five commercial garlic farms in New York and Vermont to assess how well they control dry bulb mites in a variety of storage conditions.

This project seeks to evaluate the effectiveness of the predatory mite Stratiolaelaps at controlling populations of dry bulb mite Aceria tulipae in garlic in a variety of different storage environments. By choosing five commercial garlic farms with different drying and storage conditions we hope to find the ideal range of conditions to allow Stratiolaelaps to maintain viability for long-term A. tulipae control while also keeping damage below environmental thresholds. 

Once we have successfully developed a protocol for the use of Stratiolaelaps in storage we will present our findings in newsletters in Vermont and New York, reaching over 1500 growers. We will also present our findings at conferences throughout the northeast and at garlic schools, reaching hundreds of growers. Combining this information with other emerging information about season-long A. tulipae management should allow growers nearly complete control of a pest that can reduce yields by up to 23%.