The buzz about yellowjacket season in South Lake Tahoe

SOUTH LAKE TAHOE, Calif. - Yellowjackets - they seem to appear whenever you sit down for your picnic lunch or other outside dining enjoyment in Lake Tahoe, especially in the months of July and August.

While the uninvited guests have some redeeming qualities they are predatory, sting pets and humans and are capable of stinging multiple times. Their aggressive behavior ruins many the outside activity. Yellowjackets are actually wasps but shouldn't be confused with other wasps, such as hornets and paper wasps. They are often mistakenly called "bees" (as in "meat bees").

The yellowjacket activity seen now in South Lake Tahoe is normal and average, and all the result of what the queen did back in April. She started her nest as she emerged from her winter slumber.

Yes, I did say the yellowjackets have some redeeming qualities - the eat aphids and other small pests and provide nutritious calories for bears and coyotes. They are also low-level pollinators, far below their honey bee relatives who are high-level pollinators and protected.

But they are predatory and eat flies, other bees, feed on picnic fare, fruits, carrion, and the nectar of flowers. Yellowjackets will forage for about one mile from their nest.

There isn't just one type of yellowjacket. In Lake Tahoe, there are five different species found flying about. Some build their nests in the ground, others find cavities in spaces such as buildings, sides of homes, inside walls, rodent holes and anywhere else they think is a safe place.

The queen creates her starter nest in spring by chewing plant and wood fibers, making a type of paper. When the nest is started, she begins to lay her eggs. After eggs hatch into larvae, the queen feeds her young with scavenged meat, fish and other insects. As adults, these first offspring are sterile female workers that expand the nest, search for food and care for the queen and her young. The male drones don't sting, and their main function is to be ready to fertilize a receptive queen. After they mature, the yellowjacket queen remains inside the nest laying eggs for the rest of the summer.

Getting rid of the queen as she builds her starter nest in the spring and early summer solves all issues with the yellowjackets in the summer and fall. Drones and worker bees do not know what to do without a queen to give orders and are incapable of building a new nest. Removing the queen takes out a whole colony as there is only one queen per nest.

El Dorado County Vector Control Tech Toogee Sielsch works with five others in the South Lake Tahoe office. They are tasked with treating mosquitos and yellowjackets in the area.

"Put your yellowjacket traps out in April," said Sielsch. "If you see them flying, it's too late."

Vector Contol destroys about 300 nests per year but that is a small percentage of what is located in the 160,000 acres under control by the USFS Lake Tahoe Basin Management Unit, plus all the neighborhoods. Sielsch said there is an average of one nest per acre. If 200 yellowjackets are housed in each nest there are potentially millions of yellowjackets in the Lake Tahoe Basin.

"We are not even making a dent in the total population," said Sielsch of the yellowjackets.

They will treat areas for yellowjackets along trails and near homes, trying to mitigate problems with humans. But once out in the meadows and forests, there is no way for Vector Control to treat all of that acreage.

Sielsch said to be careful when hiking as nests can be anywhere, hidden in tall brush and under the ground. Once a nest is disturbed the worker yellowjackets are released.

The yellowjackets will stick around until the first hard freeze or two, so it is possible to see them into November. They all die, a new queen goes into hibernation and the process starts again in spring. A late, cold storm in spring can cause early rising queens to die or set the development of their nests back a month.

If you are seeing the yellowjackets coming in and out of a nest, hole or opening "like an airport runway," you are seeing a nest, said Sielsch. If you are seeing them just swarm around, then its just that, an active group.

Yellowjacket traps work the best starting in spring but many are clearing off the shelves of local hardware stores now, especially before the end of outside barbeque season. They are attractors and will attract bees and yellowjackets, so if you have them, place on the outside perimeter of the yard. They will hang out there and venture inside and die, but unfortunately, with a queen still alive there will be more to take their place. The traps also attract bears who like the yellowjackets and the sweetness inside the trap.

One trap per property is enough, said Sielsch.

Sielsch said he has seen a bear dig out an underground hive, eat what they wanted and wander off, only to have a coyote follow and eat up the remains. They get stung but with their fur it doesn't affect them as much as humans and pets.

Some dogs may be allergic to stings, just as humans are. Consult veterinarians for the best method of treatment.

In South Lake Tahoe there are some areas with more yellowjackets than others. They get thirsty so being near a water source attracts them (and mosquitos as well). Yellowjackets need water, mosquitos need water and shade. If an area has both they will see more of the pesky things that will others.

There are paper wasps in the area too, but they aren't aggressive though they look similar (except the long body and the paper wasp has an orange-tipped antenna). The paper wasp won't attack unless threatened. Don't be confused by the name though...the yellowjacket builds a hive that looks like paper and the paper wasp does not. They particularly like old shake roofs and eat up the wood for their home.

There is a misconception that all bees die after they sting. That is only true with honey bees and the yellowjacket can keep on stinging as their stinger remains.

Households that find yellowjackets around their home can call Vector Control. An annual $6 per parcel tax for Lake Tahoe residents of El Dorado County is charged and allows residents to get their services for free. The West Slope doesn't have this service.

Sielsch and his coworkers treat nests or remove them. He said if people notice yellowjackets or bees going into their walls from the outside, plugging the hole will not help. Both will try to get where warmer and start chewing holes in the interior walls. They can remove the yellowjackets but honey bees must be removed by beekeepers.

If homeowners notice the small starter nests, less than the size of a fist and grey in color, contact Vector Control and get them removed. They can be contacted at 530-573-3197.

Remember, spring and early summer is the time to address the issue to keep the rest of your summer and fall peaceful.

From Wikipedia: Yellowjacket is the common name in North America for predatory social wasps of the genera Vespula and Dolichovespula. Members of these genera are known simply as "wasps" in other English-speaking countries. They are members of the same family as bees, wasps, hornets and flies and are very often thought of as bees, but they are not.