Summer is in full swing and temperatures are rising, which means it is important for growers and PCAs to continue scouting for mites in their vineyards. Once mites are established, the pests can be difficult to eliminate, so quick and effective treatment before populations escalate is the best way to minimize potential damage.

"Spider mites can be particularly difficult to control because they can develop a new generation as quickly as every seven days," says Joe Vassios, PhD, Technical Service Lead, Specialty Crops for UPL. "That means grape growers and PCAs must scout frequently and apply miticides at or below treatment thresholds to reduce their damage potential."

The Pacific spider mite is the primary pest mite for grapes in the San Joaquin Valley, but is appearing more often in certain northern and coastal grape-growing areas, where it typically wasn’t a problem in years past. Adult Pacific spider mite females vary in color from amber to greenish — later in the season, adult females can turn orange to reddish. These pests prefer the upper canopy of the vine where it is warmer, and thrive in the hotter, drier part of the grape-growing season. Other key mite species that thrive in similar conditions include the Willamette spider mite and two-spotted spider mite.

Managing mites

To address mite issues, growers should scout their vineyard at least once per week throughout the summer — especially in areas that are experiencing water stress or dust. Signs of mites include leaf stippling or webbing earlier in the summer, and growers can see mite eggs under the leaves as the season progresses. Using a 10x or a 14x hand lens, note the presence of mites and mite predators. Threshold levels for mites and other insects, and recommendations for treatment, can be found here.

Miticides from UPL provide the flexibility that grape growers and PCAs need: quick knockdown, long-lasting control and selectivity on beneficial insects and predator mites, all for excellent IPM compatibility. 

VIGILANT® Miticide (IRAC 20D) and ACRAMITE® Miticide (IRAC 20D) provide outstanding protection from spider mites at all stages. Both miticides have a short 14-day pre-harvest interval for grapes and a reputation for going easy on predator mites and beneficial insects. For most programs, VIGILANT and ACRAMITE can be used throughout the season whenever spider mites are present and populations begin to build, offering a solution that seamlessly fits within the framework of your integrated pest management regimen.

KANEMITE® Miticide (IRAC 20B) offers exceptional control, rapid knockdown and long-lasting residual activity on two-spotted spider, European red and Pacific mites while going easy on predator mites and beneficials. Additionally, its unique active ingredient, acequinocyl, makes KANEMITE an ideal member of your resistance management program.

OMITE® Miticide (IRAC 12C) offers swift relief from mites using a unique active ingredient and fuming action. It provides fast and powerful knockdown of a wide range of mites at all life stages while allowing for great coverage everywhere these pests like to hide. OMITE is also rainfast for lasting control and is an excellent rescue treatment throughout the year and especially toward the end of the season.

UPL offers advanced products and customized solutions to meet the needs of each grape grower. For a complete line of reliable protection and a staff dedicated to keeping your vineyard going strong, contact your local retailer or visit www.upl-ltd.com/us.