The scouting this week at the West Madison Agricultural Research Station did not result in any insect activity to report. Only one grape phylloxera gall (Fig 1) was spotted last week and it is recommended to start monitoring for galls at this time.

If you start seeing galls on grape leaves and are not sure whether they are phylloxera or tumid gall makers, one easy way to differentiate is to look at the surface of the galls. If the surface is smooth then it is most likely grape tumid gall maker, if the surface is bumpy or warty (Fig 1), then it is grape phylloxera. Both can be controlled with Movento which is a systemic insecticide that will be translocated throughout the plant and reach the insects within the galls. However, it is rarely recommended to treat for tumid gall maker, as they rarely if ever reach high population levels that would warrant an insecticide application. Grape phylloxera galls should be treated with an insecticide such as Movento, Assail, Danitol, Platinum or Scorpion especially if you have a history of phylloxera in your vineyard.

Thank you to Andi Nelson and Leslie Holland for scouting the vineyards.

Happy growing season!

This article was posted in Grapes, Insects and tagged Christelle Guédot, grape phylloxera, Grapes, insects, phylloxera galls.