E316 - 316: Three-Cornered Alfalfa Hopper: Monitoring, Models, and Management

Three-cornered alfalfa hopper (TCAH) is the only confirmed insect vector of grapevine red blotch virus in Vitis vinifera, yet many growers first realize they have the pest only after spotting petiole girdling in the vineyard. Cindy Kron, North Coast IPM Advisor at UC ANR, shares findings from two years of weekly sweep-net monitoring at Oakville Research Station that revealed TCAH adults are present well before bud break, suggesting grapevines are not their preferred host.

She explains the insect's life stages, why legumes serve as key feeding and reproductive hosts, and why detecting early instars remains a major...