I’m in Washington state and have a small vineyard (6 rows, 120 ft long each). This year, for the first time, yellow paper-wasps inundated my ripe grapes and destroyed over ½ the fruit. I used sevin, malathion, and Spectracide, and none had any affect.
I thought I would give your waspinator wasp nests a try next year. How many would I need in total?
Do you have any chemicals I could use on the grapes as well?
As explained in our WASP CONTROL ARTICLE, this insect will many times harvest plant parts to use for nests. In the process they will damage and in sometimes kill targeted plants. To help curb this behavior, installing some WASPINATOR NESTS around the property will help. In general, one every 50 feet is enough. Based on the dimensions you have for the vineyard, if you set out at least eight you should have enough so they see them most everywhere they travel.
I also suggest you use some of the organic sprays labeled for use on fruit and vegetables. MULTI INSECT KILLER is highly effective on wasps and can be used safely on any plant yielding edible fruits or vegetables.
Here are direct links to the information and products listed above:
Wasp Control Article: http://www.wasps.net/wasp-and-hornet-control
Organic Insect Killer: http://www.bugspraycart.com/organic/liquid/multi-purpose-insect-killer-24-oz
PS: Are you signed up for our informative twice a month Pest Report Newsletter? More info here: http://bugspray.com/bugspray_pest_report.html