A Louse Has Moved Into Colorado’s Vineyards

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Grape vines
Grapevines in a healthy state.

This might just be worse than sour grapes: A vine-withering insect called phylloxera has turned up in Grand Valley vineyards where 85 percent of the state's wine grapes are grown. The microscopic bugs have decimated other vineyard areas throughout history, beginning with the Great French Wine Blight in the late 1880s. French winemakers tried everything to stop it then, including burying live toads near grape vine roots.

But nothing worked then. And nothing works today. Once the bugs are in vine roots, the only way to deal with them is to destroy infected plants. And once phylloxera has set up shop in an area, the only long-term solution is to replant vineyards with phylloxera-resistant, hybridized plants. The cost of all that phylloxera-proofing makes the price tag of a stellar bottle of cab seem like chump change.

Colorado State University has a viticulturist and an entomologist on the case. They are surveying vineyards and have so far found four that are infected. The vineyards are spread out over the Grand Valley so the likelihood of finding more of the damaging bugs is high.

Colorado Matters host Ryan Warner speaks with viticulturist Horst Caspari and entomologist Bob Hammon.