Ah, glorious spring. What a hopeful time of year for beekeepers. Winter is releasing her hold, giving us moisture in the form of rain rather than snow. Temperatures are warming and early season plants are just starting to bloom. Insects are emerging, namely bees foraging for nectar and pollen, but there is another, less friendly garden insect. Yellow jackets.
Just what is a yellow jacket you ask? According to entomologist, Whitney Cranshaw, from Colorado State University, it is considered a ‘social wasp’ in the genus Vespula. “The most noxious species is the western yellow jacket (Vespula pensylvanica)… they readily scavenge sweets and protein-rich foods.” With such a billing, these insects are most often the culprits as unwanted guests at outdoor picnics. But it is not just our hamburgers or sugary drinks they are after. They also are eyeing our honey bee hives.
You may wonder how a yellow jacket (an insect with a stinger) can be a pest… or better stated, an enemy of the honey bee (also an insect with a stinger)? The answer is simple. As the typical food supply of yellow jacket begins to decline in late summer, they seek out other food sources. And as every beekeeper knows, those late summer hives not only contain honey, but bees. Remember the previous paragraph that stated, “…they readily scavenge sweets and protein-rich foods.”? Well, that is exactly what they will go after, both bees and honey.
To gain access to a hive, yellow jackets will attack a colony of bees. Since a yellow jacket retains its stinger, it can kill many bees, while a honey bee will lose its stinger when it stings, killing the bee. If the honey bee colony isn’t large enough, it will not be able to adequately defend the hive. In the end, a weak colony will be robbed of its honey and a large number of bees will be killed and/or eaten in the process.
But there is one thing that a beekeeper can do now to drastically reduce the likelihood of yellow jacket robbing as well as put a big dent in the local (backyard) yellow jacket population, it is to set out pheromone traps. One of the most common pheromone traps on the market is a re-useable, yellow, cylindrical container with an opening at the bottom. The lure (pheromone) is placed inside the trap. The pheromone itself works for up to 6 – 10 weeks depending on brand. After that time, you can apply more pheromone to the trap. (Most garden centers, nurseries, and big box stores carry both the traps and the pheromone lures.) If you are concerned about catching honey bees in the trap, don’t worry. The pheromone is specific to the Vespula genus. You will not catch bees in this trap.
For best results, set out these traps in early spring. (Depending on your region that may be March or April.) Yellow jacket queens (the females that lays eggs) emerge from their overwintering location. They are attracted to the traps, crawl inside, and remain there until they die of dehydration. By catching just one yellow jacket queen, you can reduce the population by thousands since she will not be able to lay her eggs. And in the world of these social wasps, those eggs would eventually turn into workers (which are the unwanted picnic guests and robber of hives).
You can leave the traps out for the remainder of spring and summer, but just be aware that at this point, you will just be catching worker yellow jackets, not queens.
You can greatly reduce the likelihood of robbing by yellow jackets. Purchase a trap or two and hang them in the area of your hives, but not next to them. If you hives are in the backyard, hang the traps from a tree, corner of the house, or even off of a fence. Your actions now will make a big difference to your hives and your backyard picnics.