Grape Flea Beetle - another consequence of a hot dry summer...

Friday, August 17, 2012

*UPDATE - Spotted Wing Drosophila has now been trapped in NS - in total 9 flies were caught last week in traps in raspberry and highbush blueberry fields - if you are concerned about SWD in your vineyards, I suggest you check out the link in my last blog on how to make your own SWD trap and begin monitoring in your own vineyards. 

Hi folks,

I've had two reports of grape flea beetle this week from the Annopolis Valley area, so I thought I'd post some information here on the blog in case anyone else is experiencing some issues with this pest.  It appears to only be attacking the youngest leaves on some new plantings so far.  When I looked at a few websites, everyone describes it as a 'sporadic' pest of grapes so I don't think we need ring the alarm bells just yet but I wanted people to be aware of what it is and what we should do about it (if anything!)! 

It's a small bluish black (often looks metallic) flea beetle about 3/16 inches long.  The adults overwinter in the bark of trees in nearby hedgerows and then migrate into vineyards in the spring... the biggest threat is for the early buds in the spring if the adults move in and start feeding and laying eggs.  The larvae will feed for a month or two on the leaves and then you can see a second generation of adults late July/August. (which is what I suspect we are seeing now!)   Unless the defoliation is severe (or on a new planting with few leaves), they don't recommend treatment at this time of year... however because this summer generation are the ones that will overwinter, if you are seeing significant numbers it may be a good idea to treat now to reduce that overwintering population so you don't have a problem next spring. 

Click to see some factsheets from Cornell, Ohio State and Omafra on grape flea beetle.  They all have recommendations on cultural practices you can do (cleaning up hedgerows, between row management, etc...).  And most sites recommend that broad spectrum sprays directed at the grape berry moth after bloom may also control flea beetle - one site suggested Sevin might be the most efficacious?

Please let me know if you have any questions or concerns about this potential pest - we've been pretty lucky so far to not have to worry about insect pests - hopefully this is just a result of the long, hot, dry summer this year!! 

And a quick reminder to mark you calendars - I see that the GGANS Annual Tour will be held on Friday September 7th, starting at 1PM at the composting facilities at North Ridge Farms in Aylesford, followed by a couple of vineyard stops at Andy and Gail Parkers' and Jim Grays' in Berwick.  Joanne will send out more details as they become available! 

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