Vendanges is finished at Jeff Coutelou’s for 2020. That is the good news, with some lovely grapes and good quantities all seemed well. Then on Saturday Jeff messaged me to say that there had been a final twist, a proverbial sting in the tail. The problem was an insect though, admittedly, not one with an actual sting. I mentioned in the last post that there had been a little ver de la grappe (grape worm moth) problem. Well, that problem suddenly worsened in the last few days of harvesting.
Some Grenache, Cinsault but especially Mourvedre were affected. The latter is a later ripening grape and no less than 60% of the grapes had to be rejected and were lost. That is a huge loss. The culprit was not the usual grape moth Eudémis which lays its eggs on the grapes, the larvae and caterpillars then attacking the grapes and spoiling them. Jeff is used to those and recognises the problem coming.
This was a new moth to the area, Pyrale du Daphné (Cryptoblabes gnidiella) or honeydew moth. This menace has been damaging grape crops (and other fruits) in Tuscany and more recently in Provence. Clearly it has spread to the Languedoc.
Three or four generations of adults appear in any year with the biggest populations coming at the end of August and into September. They feed on ripe fruit juice and honeydew from aphids, things you would find in vineyards at harvest time. The eggs are laid in the bunch and the larvae eat not just grape juice but also attack the stems. The grapes empty completely and the spoilage damages other bunches with botrytis and rot. They are much more damaging to the grapes than the usual ver de la grappe, as Jeff sadly found with his Mourvedre.
Chemical treatments are available for spraying but Jeff and organic producers generally cannot use them. There are naturally occurring bacterial treatments such as Spinosad (made from crushed sugar cane) which organic producers are permitted to use. Otherwise vignerons can try to use pheromones which confuse the male moths so that they don’t breed, confusion sexuelle. Insect traps are another option. Italian scientists are also experimenting with the use of trichogramma. These are wasps which lay their eggs inside the moth eggs meaning that the moths do not develop. These have been used successfully in other fruit production and vineyard trials seem to be promising. Whether upsetting the balance of natural order is a good thing is open to debate.
Therefore, though the 2020 harvest will generally be a good one, there was a final problem. Mourvedre is used by Jeff, occasionally for a single variety cuvée but more often to blend in various cuvées such as Le Vin des Amis and Sauvé de la Citerne. Now that this new menace is identified Jeff will look out for it next year, a hard frost in winter would help to kill off the hibernating adults. Let us hope that this is a problem which we can look back upon as a curiosity, that may be looking at it with glass half full.
More about the problem here (article in French)