Grape mealybug overwinters in egg sacs under the loose bark of trunks and cordons. In the spring, the eggs hatch and the first instar nymphs, “crawlers”, emerge and start to move to one-year-old canes or spurs. Early season management of this overwintering generation may serve to reduce the population of mealybug and help with reducing spread of grapevine leafroll-associated virus-3.
At this time, a contact product will be effective. The products registered for mealybug in Canada include malathion 85E, Clutch 50WDG, Opal/Kopa Insecticidal soap (1% – 1 L/100 L) and Vegol Crop Oil (2% – 1 L/50 L water). This is not ideal timing for an application of Movento since it will not move down into the trunk this early. Because of the lack of foliage at this early growth stage, it is highly recommended that this delayed dormant application be applied with a hooded recycling sprayer.
Treatments applied before crawler numbers peak will not provide control of crawlers that emerge subsequently. We are currently monitoring for crawlers at several sites in Niagara using double sided tape as has been done in BC and will post when crawler numbers start to increase significantly.
Check out this YouTube video about monitoring for mealybugs for more information: https://www.youtube.com/watch?v=YgL4BMK8PGg