Back in July, our neighbouring viticulturists here in Provence were spraying for what they referred to as the ‘ Pyrale de buis’ which is apparently a great problem for them. What is it and should we be worried about these moths affecting our garden plants? As an aside, someone told us the spray they use can be harmful if it drifts. Peter Oakley
Ah! There may possibly be some confusion here. William Kendrick, writing in 1841, talked of the fact that: “In France, the vines are sometimes infected by a moth or insect called Pyrale, which produces a caterpillar so injurious to the vines that they often destroy the entire crop throughout all districts.” He then went on to say: “[the] most effectual method… [is] to place amongst the vines, in the night time, lamps enclosed in glass, and suspended over saucers of oil… by repeatedly striking against the glass, in their vain attempts to get at the light, the moths fall down and are drowned in the oil.”
It’s confusing because, to many, the ‘ pyrale de buis’ is otherwise known as the ‘box tree moth’, the caterpillars of which, as the name suggests, affect (and can decimate) box hedges in a very short space of time. To add to the confusion, the problem appears to be a recent one and wouldn’t, therefore, have been known to Kendrick back in the mid-1800s. Wikipedia tells us that: “Cydalima perspectalis or the box tree moth is… an introduced species in Europe, first recorded in Germany in 2006, and subsequently [in] France… in 2009.”
According to various online French-based forums, the box tree moth (it’s the caterpillar that causes the problem) has been established in the Tarn department for about four years, but in Provence, where you are, it’s been in evidence since around 2010.
Regarding the spray your local winemakers are using, I couldn’t possibly comment. More organically, in a garden situation, pheromone traps hung to catch the males may help and, interestingly, there may be another unexpected biological solution. Referring back to Wikipedia, it seems the Asian hornet could prove a natural predator of the caterpillars of the moth. Apparently, in south-west France where the Asian hornet was already present before cydalima perspectalis arrived, “some degree of predation” has been observed, though this is not confirmed by clear, scientific results.