What's New At The Farm? 1/07/10

I'm back...

With the weekend storm the landscape is looking pretty desolate. Over a foot of snow last weekend and I guess we're officially into winter. Although there's plenty of snow out there the temps have been relatively warm so far this season so we're saving on some heating right now.

In the ever growing stack of reading materials on my desk are many catalogs that extol the benefits of "All Natural" or "Organic" insect control. One of these controls that really peeves me is traps for hornets and yellow jackets. While I'm sure some people get stung from them, and yes some are allergic, I see no reason to trap and kill a beneficial insect such as a wasp unnecessarily.

So this weeks column will focus on some of the highlights from the world of wasps. There are over 100,000 species of wasps in the world and the majority predatory. This means they lay their eggs directly into a host, which then hatches and eats the host until they pupate or when they emerge as adults. Not a great way to go for the host! Wasps are either social or solitary; social wasps live in colonies and solitary wasps live alone. Wasps that build large nests with many individuals living there (yellow jackets) are social whereas wasps that build small individual nests (like mud daubers) are generally solitary.

Adult wasps generally don't feed, and if they do they confine their appetite to nectar; hence this is why nectar producing plants are often the main ingredient in beneficial insect mixes. Having an abundant supply of nectar handy will entice the various wasps to stick around, therefore they'll be there to attack a parasitic host insect.

Several species of wasps are used for insect control in agriculture: this is called a Biocontrol. Probably the best known is the trichogramma wasp; one whom preys on moth and butterfly whose larvae are garden pests. Insects attacked include tomato hornworm, cabbage worm, corn earworm and a long list of other caterpillars.

Another species used to control garden pests is Bracoid wasps. They are tiny, barely recognizable, ranging from 1/16th to 5/16th of an inch long. They primary targets include aphids, tent caterpillars and armyworms. And, last but certainly not least are the Ichneumon wasps; long and slender wasps that range from 1/8 inch to 1½ inches. They commonly feed on cutworms, corn earworms, white grubs and various other caterpillars.

Other than parasitic wasps we use in agriculture, other wasps have their place here as well. Mud daubers usually capture spiders, paralyze them and stuff them into their nests with a single wasp egg. Once the wasp hatches he has a live and relaxed meal awaiting him. Each species of mud dauber have a preferred spider list - you wouldn't want to get one that doesn't taste good. I think mud daubers are certainly one of the most interesting wasps to watch; we've had them at our camp for many years, but no one has yet to be stung. They are generally only aggressive if they're being handled.

Yellow jackets are certainly well known, but how much is really known about them. From working in the fields here at Johnny's we know the following things: First of all they like sweets and yeast. A sunny day in the melon field and we're sure to spot lots of them feeding on cut or split melons. And yeast; when we ferment tomatoes, cukes and melons for seed production we used yeast. There's always a few getting drunk in the bottom of the yeast pail. They also can be fairly aggressive if their nest is disturbed; I've seen them disturbed in mulch hay piles and I was glad I had a tractor cab to protect me. On the positive side they consume insects and spiders but also have a fondness for sweets hence they are often nuisances at picnics. Unlike honeybees they can sting multiple times and have a strong venom.

Black faced hornets are not hornets but wasps. They are perhaps one of the more aggressive wasps, but they are really only defending their home. Years ago I had a nest over a door in the barn; it was interesting to watch the progress. At first, when only the queen was building the nest, progress was slow but steady. As more workers were added the nest grew in leaps and bounds; you could see progress every day. At the end of the season it was perhaps the size of a basketball. All season it was there, I stood there often and watched them, I opened the overhead door daily as this part of the barn housed my pigs, and I never got stung. Everyone who saw it advised me to take it down but I'm not partial to destroying something for "something" that might happen. I'm also not partial to be told what to do.

I have nests in the attic of my garage, under the eaves of the henhouses and also at camp both inside and out. We have them at work; although I must admit we do destroy some of these nests here. Most of the nests we have are from paper wasps. They don't seem very aggressive which is a good thing. They do work their way into the house during the fall and come alive in the spring once the weather warms up. One learns not to leave the your work clothes on the floor the night before or you may get a nasty sting in the morning. Not a great way to wake up; stung somewhere you'd rather not be stung at some early time in the morning and a volley of colorful language to follow which wakes the entire household up.

Next week - Hornets.

Brian