Yellowjacket "Fun Facts"

*Warning: Very few of these "Yellowjacket Fun Facts" are actually "fun"

Many of us occasionally notice yellowjackets sneaking in and out of our hives. For most of the summer, a strong colony of bees can keep the wasps at bay, but sometimes in the fall wasp robbing can suddenly get much more intense. Why does this happen? What are the wasps up to? And what should you do to keep your bees safe? 

One cool thing about Betterbee is that we've got an insect scientist (Dr. David Peck) on staff who can sit down and prepare a few key bullet points about yellowjackets to help beekeepers understand one of the many enemies of the hive. Enjoy some of these "fun" facts!

These paper nests were made by paper wasps (Polistes dominula). The nests on top were made from natural wood fiber, but the nests on the bottom were made when the wasps were given colored construction paper. You can even see where one nest was started with natural fibers and then switched to yellow construction paper! All wasp paper is made from plant fibers in this way.

Yellowjackets, hornets, and paper wasps are all "wasps," just like honey bees, bumble bees, and other native bees are all "bees" 

Wasps and bees (and ants) are all cousins of one another. All ants live in colonies headed by a queen, while only a small number of wasps and bees do. Despite the large number of solitary bees and solitary wasps, we're usually most familiar with the social bees (like honey bees) and social wasps (like yellowjackets) because their lifestyle is such a successful way to survive and thrive.

Yellowjacket (and similar social wasp) colonies start with a single mated queen in springtime

The queen builds a small nest and cares for her young until they are old enough to serve as the first "worker" generation. Once the first workers mature, the queen remains at the nest and limits herself to egg laying like a honey bee queen, while the workers take over everything else. The colony grows all year, enlarging their nest and continuing to forage.

Yellowjackets eat other insects for protein, while honey bees eat pollen for protein

Both wasps and bees will bother people as they drink soda or eat snow cones, because both will happily drink sugar-water for cheap energy to fuel their colonies. However, the protein source that lets their brood grow is wildly different. Wasps hunt for caterpillars, crickets, spiders, and other sources of animal protein to provide nutrients for their larvae. Bees, who get their protein from flower pollen, don't need to hunt for insects to eat. This is why some scientists call bees "the vegetarian wasps" to distinguish them from their waspy cousins. When yellowjackets and other wasps are buzzing around your hive, they may be trying to steal honey, but they will also take brood or even discarded dead bees back to their hive as a protein source.

Beekeepers don't want to come collect your wasp nest!

A common (but frustrating) occurrence is being called out to collect a swarm of bees, gathering your swarm-catching equipment, and driving across town, only to have the homeowner point you towards a yellowjacket nest hanging from a tree branch. Before you agree to collect a swarm, it's often useful to interrogate the caller to make sure that they've really got honey bees. One easy test is to ask if the "bee nest" is safely inside a wall or a tree, or if it's an orb hanging from a branch just like a "Winnie the Pooh" cartoon. For some reason, cartoonists and illustrators refuse to learn the difference between how wasps and bees build their homes.

The cells and walls of yellowjacket nests are made of paper, not wax

Wasps don't have beeswax glands, so instead they have to build their cells out of chewed wood pulp. Chewing up wood fibers and mixing it with their saliva yellowjackets build both cells for their larvae and paper wrapping to surround their nests. Yellowjackets or paper wasps held in captivity can be given a sequence of colored construction papers, and they will use them to create rainbows of cells! Paper cells can't hold wet honey, so the small amount of spare food stored in a yellowjacket nest is stored inside the larvae, who will vomit up sugary food to sustain the adult wasps when there isn't any tree sap or flower nectar for them to eat.

A can of wasp-killing insecticide can be sprayed from a distance into the entrance of a wasp nest to kill them, reducing the raiding pressure on honey bee hives nearby

This partially dissected social wasp nest from Dr. Peck's collection shows the multiple tiers of paper cells, as well as the multiple layers of paper sheathing that the wasps built around their nest.

If you go this route, you shouldn't be stingy with the spray. Spraying is best done in the late evening, in the dark, since visual predators like wasps are less likely to fly if they can't see, and all of the wasps will be inside the nest for the night. Be careful if you spray a wasp nest, because…

Wasps can sting multiple times, and yellowjackets can sting through a beekeeping jacket if they're determined to do so

If you're spraying a wasp nest to protect your bees, or trying to make a little cash by killing wasps in your neighborhood, your veil and jacket will provide some protection from the wasps. However, beekeeping gear is designed for bee stingers, and many wasps can sting through a tight-fitting jacket. Since yellowjackets don't have barbed stingers like honey bees, they can sting and inject venom repeatedly without dying, so you don't want to linger long in a cloud of angry wasps!

Yellowjacket nests in temperate climates die each winter

In the fall of each year, yellowjacket colonies start making new males and queens. These reproductive wasps will mature, mate, and the queens will prepare to freeze solid for the entire winter. When they thaw out in spring, they'll each start a nest of their own. The worker wasps in the original colony will die when freezing temperatures arrive, removing the threat to nearby bees until the next year's wasps appear. If you don't want to spray insecticide on your local yellowjacket nest, you can just wait until a few days of hard freezing weather. Once the wasps are all dead, you can even cut down the nest and peel off a few layers of paper to see what the wasps were building all summer. 

In general, a strong bee colony with a reduced entrance should be able to keep wasps at bay. However, a wasp nest right next to your hives could send enough worker wasps to overwhelm the guard bees. In that case, removal of the wasp nest is one good option. If you can't find the wasp nest to remove it, you can also use a robbing screen or a HiveGate to prevent wasps from entering and raiding the hive. The robber screen may confuse the wasps about how to get in, while the HiveGate forces the wasps to enter and exit through a long tunnel full of guard bees.