A mealybug species and its reproductive characteristics is a rising concern for grape producers in California.
Grape growers are starting to shift their focus to a different species when it comes to mealybug pressure. “We’ve got about six mealybug species that can be found in vineyards in California,” Cooperative Extension Specialist Kent Daane says. “The mealybug that’s the most common throughout California is the native grape mealybug, but the bug growers are most concerned about is the vine mealybug. This is an invasive species from the Mediterranean region and the one we’ve got in California came from Israel.”
Daane says the mealybug is becoming a bigger problem for growers simply due to the species’ breeding characteristics. “One of the things we have to remember is that the native grape mealybug, the one we’ve been worrying about for the last 40 years, has two generations per year and will average 150 eggs per female. Vine mealybug in the Fresno area will have as many as seven generations a year and each female will average over 200 eggs.”
Daane says it’s a simple numbers game. “Just think about a population explosion with faster generation turnover and more eggs per female. It causes more damage because it’s feeding more, it’s creating more honey dew because it is eating faster so it poops more. You’ve got a faster buildup of numbers and more numbers equals more damage.”
Find out more about the vine mealybug at the UC Integrated Pest Management website.