Red Blotch

Resources

Napa UCCE - Red Blotch

Sonoma UCCE

TCAH Degree Day Model

LAMP Assay Video

Academic Research

Timing the Implementation of Cultural Practices for Spissistilus festinus (Hemiptera: Membracidae) in California Vineyards Using a Stage-Structured Degree-Day Model

Feeding and Reproductive Hosts of Spissistilus festinus (Say) (Hemiptera: Membracidae) Found in Californian Vineyards

Identification of Nonhost Cover Crops of the Three-Cornered Alfalfa Hopper (Spissistilus festinus)

Spissistilus festinus (Hemiptera: Membracidae) susceptibility to six generalist predators

Influence of Riparian Habitat and Ground Covers on Threecornered Alfalfa Hopper (Hemiptera: Membracidae) Populations in Vineyards

Survey of Vineyard Insects and Plants to Identify Potential Insect Vectors and Noncrop Reservoirs of Grapevine Red Blotch Virus

Use of Ground Covers to Control Three-Cornered Alfalfa Hopper, Spissistilus festinus (Hemiptera: Membracidae), and Other Suspected Vectors of Grapevine Red Blotch Virus

Spatial Associations of Vines Infected With Grapevine Red Blotch Virus in Oregon Vineyards

TCAH Degree Day Emergence Model

The sheet below forecasts the expected time of emergence in the current year for both first generation TCAH nymphs and adults. For forecasting, the model uses the current years actual climate data (to date) - if no climate data is available for the current year, a running average DD/day starting in 2020 is used to help determine time of emergence.

Sheet Notes

Lacewing Release: This strategy is based on results from previous work (Spissistilus festinus (Hemiptera: Membracidae) susceptibility to six generalist predators), which found significant predation of 1st and 2nd instar TCAH nymphs by green lacewing (Chrysoperla rufilabris) larvae. The timing of release was determined with the help of Koppert, and is based on the dispersal of lacewing eggs on the groundcover, and how long it takes for those eggs to hatch and become "voracious" (roughly 2-3 weeks from egg to potential predation).

TCAH DD MODEL (2020-2023)

UCCE TCAH Girdle Survey - 2023

The below information is voluntarily collected by growers with the help of Napa UCCE. If you would like to participate, CLICK HERE to access the field survey and follow the following instructions:

Choose a block that is a red variety.
Walk both sides of a few rows within the block (ie 1 row in the north, 1 row in the middle, and 1 row in the south). Make note of the row numbers and/or mark the rows with flagging tape to be able to return to the rows in subsequent scouting passes.
In each row, look for single red leaves on an otherwise healthy vine - these will typically be due to girdling damage.
Once girdling damage has been confirmed, fill out the survey.
After completing the survey, remove any petioles or laterals that had girdles, so as not to count them again on the next pass.
Continuing scouting the row and repeat the process until you have walked the entirety of both sides of a row.
Repeat scouting every 1-2 weeks, in the same rows.

UCCE Red Blotch Yellow Sticky Trap Data - 2023

The below information is voluntarily collected by growers as well as UCCE. For more information on UCCE red blotch information, CLICK HERE.

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