Vine mealybugs (VMB) are stirring about on the California central coast, according to Monica Cooper, staff research associate, UC Berkeley.
“They have begun developing and moving up the trunk,” she says. “They haven’t yet laid eggs this season, although they should be doing so soon.”
There is more VMB activity in the coastal areas than inland, according to Mark Battany, San Luis Obispo County, Calif. farm advisor. “Both vines and VMB have a shorter winter in coastal areas than in inland areas.
“In most areas, vine shoots are still quite short, but growing rapidly. Right now, all life stages can be found under the bark. The population will increase later in the season, with crawlers moving onto foliage. Ants still frequent vines where VMB is found, but their numbers aren't as high now as they will be later in the season.”
Even the late frost conditions that occurred in many areas probably won’t affect VMB populations, according to Battany and Cooper.
“As long as temperatures warm up during the day, as they have, VMB feeding and activity will not be disrupted,” Cooper says. “Also, since they are feeding deep under the bark of the trunk and not on the leaves, they are not as susceptible to damage from frost.”
Overall, the winter was relatively mild insofar as absolute minimum temperatures and probably did not have any significant effect on VMB.
“The insect survives quite well in some of the coldest regions,” Battany says. “The April freezes have damaged numerous vineyards, but probably won't slow the VMB much, if at all.”