Look out for Phylloxera in Mesa County
The Upper Grand Valley Pest Control District (UGVPCD) and the CSU Tri-River Extension Office have joined Mesa County to educate our community on different pests in the area, and to protect local agriculture and natural surroundings from their potential harm. Phylloxera, a tiny but destructive insect pest that poses a major threat to vineyards and ornamental grape plantings, is October’s Pest of the Month.
Phylloxera (Daktulosphaira vitifoliae), which is related to aphids, is typically identified via observation of stunted vine growth, yellowing leaves and eventual decline in vine health and diminished fruit production. This is because Phylloxera are tiny, yellow-green insects that feed primarily on roots and overwinter as eggs at the base of grapevine roots. Phylloxera can also feed on leaves, causing bumpy galls on the undersides of leaves.
Once hatched, Phylloxera nymphs feed on grapevine sap, disrupting nutrient flow and often causing root or leaf galls. Phylloxera are most damaging to Vitus vinifera, which is typically associated with European wines. There is no control mechanism for Phylloxera, however, growers can overcome the challenges of growing vinifera species by planting hybrid varieties.
What to watch for:
- Tiny pale eggs on grapevine roots or leaves in early spring
- Swollen or knotted vine roots, or blister-like leaf galls.
- Stunted vines, yellowed foliage or poor vine vigor.
- Reduced fruit yield or quality.
If you suspect grapevines on your property may be impacted by Phylloxera, we encourage you to check out the Phylloxera in Colorado Grapes-2016 report from the Colorado State University Extension Office. Be sure to time any management interventions to minimize impact on pollinators and beneficial insects.
Contact Mesa County Weed and Pest at weed.pest@mesacounty.us or 970-255-7121 with any questions or concerns related to this pest.
