It's not quite the Spanish Inquisition or the Texas Chainsaw Massacre but the glassy-winged sharpshooter (GWSS) evokes much the same sense of horror among winemakers and grape growers of California, home of America's premium wine making regions. Daryl Groom, Australian-born winemaker, now working at California's Geyser Peak winery, related the tale at lunch on a visit to Melbourne recently.

According to Daryl, the GWSS (homolodisca coagulata), spreads bacteria which cause Pierce's Disease, a vine infection that has already devastated vineyards in southern California and could threaten the long-term viability of that state's US$33 billion wine industry. So serious is this threat to the US wine industry that a state of emergency was declared in June with federal/state funding of US$36.3 million allocated in an attempt to control the pest.

Seems that the GWSS is a voracious sapsucker that in recent years has emigrated from Florida to California, most probably during the transportation of ornamental citrus plants. About the size of your little fingernail, the sharpshooter injects its proboscis into the trunk of the vine and while sucking sap deposits a bacterial glob (Pierce's Disease) which blocks sap flow and kills the vine.

What is the relevance of the GWSS to Australia? Students of wine history will recall that the vineyards of the world, including those of Australia, were nearly obliterated in the late 1800s by the vine louse, Phylloxera. The louse, a parasite native to American grapevines, was presumably spread by international trade in vines and vine cuttings. Who's to know when the first batch of free range GWSS eggs will arrive on these shores to repeat the phylloxera invasion? GWSS link: http://plant.cdfa.ca.gov/gwss.

Tastings

Pieropan Soave 1999
Veneto, Italy. Light gold. Fragrant apples and pears on the nose, a hint of lemon. Mid-weighted and medium dry. A pleasant drinking wine of generous fruit showing balanced, soft acid at the finish. Rating: silver. Cellar: to 2003. Price: around $AUD23.

Haselgrove Lost Sheep Shiraz 1999
Wrattonbully, north of Coonawarra. Cherry-red, a tinge of purple. Spicy lifted nose, subdued oak underneath. Raspberry-like fruit on the palate with an elegant mix of soft tannins and acidity. Light, fresh style for less substantial main courses. Rating: silver. Cellar: to 2005. Price: around $AUD15.

Geyser Peak Alexander Valley Meritage 1997
California, USA. Dark crimson. The Californian "meritage" tag indicates a blend of Bordeaux grape varieties, in this case cabernet sauvignon, merlot, petit verdot, cabernet franc and malbec. The nose is concentrated, almost inky. The palate full and intense, with fine, chewy tannins. French oak provides a solid foundation without undue prominence, the aftertaste is long and likeable, reminiscent of ripe blackcurrants. Rating: gold. Cellar: to 2012. Price: $AUD50.

© Martin Field