By Darin Allred, Ph.D., Technical Sales Support, Arysta LifeScience

When it comes to pest problems for California grape growers, you don’t have to look much further than the Pacific spider mite to get to the heart of the matter. Pacific spider mites have become one of the largest threats to high-quality crops, as high densities of the pest can reduce Brix and yield.

Tetranychus pacificus – more commonly known as the Pacific spider mite – is the primary pest mite species for grapes in the San Joaquin Valley and appears to be spreading to certain North Coast grape-growing areas. Adult Pacific spider mite females vary in color from amber to greenish; later in the season, adult females can turn orange to reddish. Adults usually have two larger spots toward the head and two spots toward the rear. Pacific spider mites often prefer the hotter, dryer part of the grape-growing season and can be found in the warmer, upper canopy of the vine. If not controlled, Pacific spider mites can cause extensive damage and reduce Brix and yield.

Depending on location, growers also should be on the lookout for the Willamette spider mite, Eotetranychus willamettei, and the two-spotted spider mite, Tetranychus urticae, although the two-spotted spider mite rarely causes damage to grapes in California. Willamette spider mites are pale yellow with spots along the sides, and they lay eggs (which are slightly smaller than Pacific mite eggs) that have a fine papilla (hair) that tapers at the top. Willamette mites often are considered an early season mite, as they generally prefer cooler weather and the shady parts of the grape plants.

In evaluating treatments and resistance management options, grape growers often trust the power and control of ACRAMITE^®, KANEMITE^® and OMITE^® Miticides in the successful fight against the Pacific spider mite and other spider mite species.

ACRAMITE-50WS has a 14-day PHI on grapes and fast knockdown and long residual activity while KANEMITE 15 SC has a 7-day PHI on grapes and fast knockdown activity against the spectrum of spider mite species found in vineyards, making it a good choice for late-season applications to help clean up escape populations as harvest dates approach. Research conducted by Dr. Frank Zalom, University of California-Davis, and other researchers at the International Organization for Biological and Integrated Control (IOBC) have shown that ACRAMITE and KANEMITE are the top two miticides for softness on predator mites and are the only two categorized in IOBC Class 1 (harmless) to predator mites for both direct sprays and leaf surface residues. Therefore, these two miticides are the most compatible with IPM programs in grapes – meaning they won’t cause secondary insect outbreaks or spider mite resurgence. 

OMITE 30WS has a 21-day PHI and is an excellent “go-to” miticide for heavy infestations and webbing, as its unique fuming action penetrates into webbing as well as nooks and crannies where other miticides can’t reach. OMITE also is soft on beneficials and compatible with IPM programs.

To stay on top of mite pressure and to plan treatment timing, the University of California Cooperative Extension offers a mite monitoring form for tracking spider mite development and activity.

To learn more about ACRAMITE, KANEMITE, OMITE and the entire portfolio of Arysta LifeScience crop protection products for grapes, contact your crop protection retailer, visit www.ArystaSpecialty.com/Grapes or call 866-761-9397.

^{OMITE is a restricted-use pesticide. State registrations may be pending. Always read and follow label directions. ACRAMITE and OMITE are registered trademarks of an Arysta LifeScience Group Company. KANEMITE is a registered trademark of Agro-Kanesho Company. Arysta LifeScience and the Arysta LifeScience logo are registered trademarks of Arysta LifeScience Corporation. ©2017 Arysta LifeScience Group Company. SPC-1707 #11}