I’ve kicked off my summer reading with Wasp and Bee Management on Grapes by Jody Gangloff-Kaufmann, PhD, NYSIPM Program, Cornell University. I liked the bit at the end where the wasps eventually swarm around a bit of fish suspended over a bucket of soapy water, fall in and drown, although the heading Bald-faced Hornets are Aggressive has stayed with me. Things of concern to grape-growers are, apparently, yellowjackets, paper wasps, the bald-faced hornets, European hornets, and bumble bees. I don’t even know if we get these things here; avispas and algo como avispas, wasps and something like wasps, is about as entomological as we local farmers get. Bees I know and love. They can stay, and if they needed the grapes that badly, I’d let them have the lot. (Save The Bee)
I really, really don’t like killing things, however this farm with its water, fruit and vineyard is an ideal habitat for human beings and the wasps (whatever sort they are), and despite my best efforts to be tolerant, we don’t rub along. In fact, a certain person got bitten on the hand, developed a trout pout, and went all funny only yesterday. He thought he was going to die, but he didn’t.
I’ve knocked a lot of nests down from under the roof tiles, but over the last week the level of buzzing in the trees nearest to the vineyard has gone up a few notches. It seems they have finished hunting out there somewhere, and are now scavenging round here so I’ve been studying the various methods of getting rid of them. So far the most tempting include:
Plastic bottles part-filled with some sticky drink suspended from branches. Wasps go in (either though holes punched in the sides, or, if you’ve lopped the neck off, from the top) and they get sticky and don’t come out. There’s an ingenious variation on Tipnut in which the top third of the plastic bottle is inverted and shoved down into bottom to make a nice funnel entry. Beer, Coca-Cola, and Fanta orange are listed among the most alluring choices of bait.
The bucket, soapy water and suspended fish method (as outlined above), although ham is also effective – good news for us in the Sierra de Cadiz.
Inflated paper bags dangling from vines and fencing. Wasps think they are the nests of a rival faction and skedaddle . . . although this method has failed with the ones here which are clearly more perceptive.
Writing on groworganic.com, Tricia recommends a spray containing lemongrass oil, clove oil, rosemary oil and geranium oil, and spraying after dark and early morning when wasps are sluggish while wearing ‘long sleeves, long pants, gloves and a veil’. Interestingly, instead of bashing the nest down with a stick and stamping on it, she suggests removing nests at night, putting them in plastic bags and shoving them in the freezer. The idea of forgetting about them until you happen to be rummaging around for something to eat six months later is pretty nasty. That’s the sort of thing that could happen in my freezer.
The classic jam jar trick gets a mention on tipnut.com. Cut a small hole in the jar jar lid, smear the underside with jam. Pour some nice orange juice inside the jar, and pop the lid back on.
‘Point the nozzle at the nest, shoot and watch ‘em die,’ says Howard Russell of Michigan State University Diagnostic Services, who takes a more direct approach. ‘Small, exposed paper wasp nests are easily controlled by aerosol wasp sprays that produce a concentrated stream of juice that has a range of 15 to 20 feet. Paper wasps do not cover their nests in a paper maché envelope like those of yellowjackets and baldfaced hornets, so their brood cells and workers are exposed and vulnerable.’
Avoid the plants which attract wasps, suggests Functionalgardens.com who read that in Cornell University’s Attracting Insects’ Natural Enemies. These include Queen Ann’s lace, parsley, dill, dahlias, daisies, asters, cosmos, tansy, and yarrow. Instead, grow the stuff that repels them, says Bestplants.com: ‘Plants such as wormwood, eucalyptus, mint and citronella are natural wasp deterrents’.
‘Hang a sandwich filled with water,’ is the second, more cryptic, piece of advice from bestplants.com: ‘This will make the wasps think there is a spider web on your door which can trap them.’ No matter how many times I read that, I can’t begin to imagine what they mean, but it sounds effective.
‘There may be a way to physically bar the wasps from entering the vines’ fruiting zone by using very fine-mesh nets over the vines,’ says Wes Hagen of winemakermag.com, who adds that Grape Pest Management (next on my reading list) produced by the University of California, suggests doing “wasp battle” i.e. finding and eliminating nests at night with a flashlight covered with red cellophane as a safety precaution. ‘Wasps are much less active at night, and the red light should be invisible to them, giving you the advantage of safety and stealth.’
Having failed with a hose-pipe, my preferred weapon of choice is a rolled up magazine. Dress appropriately for war action, try to attack when wasps are drowsy (i.e. early mornings, late evenings), and attempt to hide a bit because if they see you, they’ll go for you.