Wasps: The Farm's Best Friends

When most of us think of wasps, it does not conjure up the same warm fuzziness as does the family pooch or kitty.  Rather, it is more likely that our relationship with wasps consists of spraying them with a can of toxic chemicals so they will not be around to sting us and our families.

 

So you may be surprised to learn that wasps are among the farm's most beneficial insects.  Most wasps feed on other insects in some part of their life cycle, often the more vulnerable, soft bodied type such as the caterpillars and aphids that plague our vegetables.

 

There are a number of different types of wasps at the farm, so lets start with the most familiar.  Paper wasps of the Polistes genus are the ones that build paper nests with open celled bottoms on sheds, garages, outbuildings and so on.  We have two of these species at the farm: one is striped like a yellowjacket and the other is black with rust colored bands.  These are voracious predators of cabbage moth caterpillars (the ones that eat our broccoli, kale, cabbage, bok choi and so on).  Earlier this spring, we observed them hunting a mature broccoli patch, sometimes several wasps per plant and eating the caterpillars.  Kaufman's Field Guide to Insects of North America describes these wasps as "generally placid" and I've found the same - if left undisturbed, they won't sting.  In addition to Polistes, there are many other beneficial wasps and hornets at the farm, although less common.

Most of the other helpful wasps we have at the farm are parasitoid - they lay their eggs on or in their prey so that the young can hatch and immediately begin feeding, thereby killing the food source.  These wasps are a more ancient form with a long ovipositor that they use to lay their eggs on the host.  It is unclear whether most of these wasps ever developed the ability to sting; I've held most of them in my hand, often many at a time, with no stings or attempts by the wasps to sting.  These parasitoids are also smaller than the paper wasps, some about the size of a common gnat.  Unlike the paper wasps, only the larva of the parasitic wasps are carnivorous and devour their host, the adults feed on flower nectar.

Brachonid wasps prey on large caterpillars such as the hornworms that eat tomato plants and are naturally occuring in this region.  If you see a large green caterpillar with small white eggs on its back, these are brachonid eggs.  The larvae will eventually eat and kill the caterpillar.  

The other wasps described below cannot survive over winter and we have to bring them in every season to help us with pest control.  Pediobius preys on the Mexican bean beetle.  If you were a farm member 5 or 6 years ago, you might remember the shortage of beans.  The bean beetle basically destroyed the entire season's crop.  The next season we began bringing in Pediobius with fabulous results!  These tiny wasps controlled the beetle better than we ever could and ensured a good bean crop.  So next time you have green beans for dinner, think of the little wasp that makes it possible.

Diglyphus is just as important to us for our swiss chard, beets and spinach.  The leafminer fly also ruined our chard and spinach crop a number of springs ago, leading us to bring in Diglyphus.  Just as with Pediobius, as long as we bring them in at the right time and in the right numbers, they provide great leafminer control, which allows for good chard, beets and spinach crops.

Aphidus is new to us this season and we are trying them out in the hoophouse to control the aphids eating the tomato plants.  So far so good - the aphid infestation seems to have halted and the plants look vigorous.  We'll keep an eye on them and assess their performance at the end of the season.

Finally, we bring in Trichogramma wasps to control the corn earworm.  These wasps are the tiniest, about the size of a grain of sand and barely visible to the naked eye.  This allows them to get inside the fruit (tomatoes and peppers) where the corn earworm is feeding and lay their eggs on this generalist pest - yes, corn earworms also love to eat tomatoes and peppers.  Like the others, these wasps will reproduce and then die off in winter.

As you can see, wasps are a critical part of our pest control strategy and an integral part of the farm.  They allow us to produce organic vegetables without using pesticides.  Many many thanks to our good friends - the wasps!

Summer Intern, Samantha Keegan,

Learns How to Extract Honey  

It was a hot dusty Sunday in July. I arrived around ten in the morning to meet with Farmer Dennis and Bee Man Con for the extraction of honey.

Preparations prior to my arrival included spraying a natural product called "Bee Be Gone" (an organic compound that which clears the honey box containing 10 frames of bees by creating an unpleasant scent). The hive is then cured with an air tunnel attached to the bottom to create airflow overnight.

Honey is ready to be harvested when a thin layer of wax called a cap over each cell. The cap is created by the bees to ensure that after they have removed the moisture from the nectar. This is how the beekeeper knows when the honey is ripe. These thin wax caps need to be removed prior to extracting the honey. Three different tools are used to get rid of the caps, a knife, a hive tool, and a hairdryer. The knife, heated before use, is to gently shave off the caps from both sides of the comb, and to level the honeycomb out with the frame. The hive tool resembles a long toothed comb and is utilized by raking it along the caps just below the thin layer of wax in order to lift off the caps. The hairdryer melts away the thin caps.

After removing the caps each frame is placed into the extractor which can hold four at a time. The extractor we used held four frames in a basket suspended in a cylinder attached to a pole in the center was a handle. Then the handle was cranked at a high speed forcing the honey to splatter onto the cylinder's walls, running down the sides through holes into the base well.

We fell into a rhythm much like worker bees......raking the wax, shaving the wax, cranking and cranking. And what a well of honey it was. It is estimated that we extracted over 100 pounds of honey from 11 of the farm's hives. When the bottom well was full we filtered the honey into a bucket through a finer screen. That bucket had a valve near the bottom making filling the jars a swift job. The leftover honey in the comb is left to nourish the bees, as honey is their favorite treat.

Where is the farm honey? It is being distributed by Ledemete Grass Farm during their chicken and pork distribution at the Resurrection Lutheran Church at the corner of Welsh and Mann Road. The next distribution will be Friday, August 24th.