Wednesday, April 14, 2010

America's most wanted moth.

The European Grapevine Moth (Lobesia botrana) has recently been found for the first time in the United States. This nasty little pest unfortunately made it's first port of call the Napa Valley; ground zero is Oakville where I work, with another isolated population having been found east of the town of Napa where I live. I can assure you this is purely coincidental.
L. botrana is an extremely serious threat to the wine industry as this particular moth does not feed on the grapevines leaves, but rather on the flower parts and inside the maturing berries. It was recently confirmed by the Napa County Agricultural Commissioner that several Napa Valley vineyards actually sustained significant crop losses last harvest. Besides natural dispersal, the movement of fruit, personnel (yikes, Vinogirl in her Vinomobile perhaps?) and machinery, coupled with the fabulous Napa Valley climate make this pest a very grave threat to other areas of the state. Large expanses of Napa County are now under quarantine.
The moth has a rather complicated life cycle comprising of 5 larval instars (the main offenders), and 3 generations of adults. Getting rid of these little fiends is going to prove to be quite difficult I'm afraid. Eradication efforts valley-wide will include; multiple applications of insecticides, the use of a bacterium (Bacillus thuringiensis) which produces a protein that acts as a stomach poison and biological controls, such as the release of tiny parasitic wasps that efficaciously oviposit the moth eggs and the dispersal of a synthetic sex pheromone so that male moths are unable to locate females.
There is a nasty little rumour going around as to how L. botrana came to be in the Napa Valley in the first place which doesn't suggest the probability that the moth was a simple stowaway. However, it is likely just that: a rumour. But isn't it at least conceivable that the French, fed up with the New World stealing it's oenological thunder, simply packed the moth's luggage for it and sent it to the Napa Valley to at long last avenge their countrymen for the American initiated phylloxera epidemic of the 1870s? Or is spending more of my time with vines than people turning me into a conspiracy theorist?

5 comments:

Thomas said...

Nothing wrong with being a conspiracy theorist, especially when everyone is out to get you...

Me, I vote for the bug having gotten here in a combination of ways, not the least of which might be as contraband. Its invasion puts the agricultural quarantine system into question, too.

Thud said...

As long as I don't get the blame!

Vinogirl said...

Thomas: Did you ever experience a quarantine situation in the Finger Lakes?

Thud: Hang on...now that you mention it!

Jamie said...

Can't you use sexual confusion? Pretty widely used in Europe. Bayer do a product.

Vinogirl said...

Jamie: Yes, they can release a pheromone (don't know who makes it here in the US, I'm assuming you are in Europe), that confuses a male as to the whereabouts of the real females, delaying mating. The female becomes a bit past her best and so no viable legs are laid. I'm sure the county and industry will be using every method of eradication at their disposal.