Historically at Le Pommier Farm, we predominantly made use of chemical pest control methods to eradicate grape and vine mealybugs in our beloved vineyards. Both grape and vine mealybugs are major pests. They’re also hard to kill with chemicals because they have waxy coatings that resist absorption.
In 2019 we have opted for a more environmentally friendly, yet very effective pest control method, by utilising the natural enemies of the mealybug to watch over our valuable vineyards.
One of the natural predators of mealybugs is the anagyrus or vine mealybug parasitoid wasp (Anagyrus pseudococci.) It stings the mealybug and lays an egg in it. This stops the mealybug from feeding, and the wasp larva will consume the mealybug and emerge as an adult.
Adult wasps will emerge from the mummies within one to five days (depending upon the ambient temperature). Immediately upon emergence, the wasps will mate and begin searching for suitable hosts, i.e. adult mealybugs. The subsequent established generations of the parasitoid will effectively control the mealybugs in the longer run.
Another natural predator of the mealybug is Coccidoxenoides perminutus. Previous studies have shown that Anagryus pseudococci, along with Coccidoxenoides perminutus, are the dominant naturally occurring mealybug parasitoid species in grapes in South Africa.
Anagryus pseudococci have a short life cycle of ~14 days, at 26–27˚C, excellent searching ability to find hosts, a parasitising capacity of several mealybug species and excellent dispersal ability. Therefore, it has an excellent prospect of performing well as a biological control agent in the South African environment.
Le Pommier Farm has in recent weeks deployed a couple of thousand of these extraordinary wasps in our vineyards, which spells very bad news for any mealybug that dares to infest our vinyards. In 2019 we look forward to yet another superb quality harvest, with the aid of our new little friends.