Warmer weather brings all creatures, great and small, out of their hiding spots. As we shake off the frosty mornings and start sorting out the yard, we remind ourselves to take care as the yellowjackets are here.
Most of us see yellowjackets, and our first instinct is to get rid of them. They can be aggressive, and their stings hurt!
But yellowjackets aren’t all bad. In fact, you might want to learn to tolerate them while carefully avoiding them because they can be an important part of the environment.
What We’ll Discuss:
What are Yellowjackets?
Yellowjackets are a type of social wasp commonly found throughout the United States and the rest of the world.
The term yellowjacket is actually a general term that encompasses many different types of wasps in two different genera (Vespula or Dolichovespula).
Yellowjackets are some of the most aggressive wasp species. They’re recognizable by their yellow and black striped abdomens but are often confused with similar-looking species like paper wasps and hornets. Plus, some are black and white, making identification harder.
There are many varieties found across North America:
- Prairie yellowjacket (Vespula atropilosa): yellow and black, found in west and midwest.
- North American yellowjacket (Vespula alascensis): yellow and black, found across North America.
- Eastern yellowjacket (Vespula maculifrons): black and yellow, found in the east.
- Western yellowjacket (Vespula pensylvanica): black and yellow, found in northern, temperate regions.
- Bald-faced hornet (Dolichovespula maculata): white and black, found across North America.
- German wasp (Vespula germanica): yellow and black, originally from Europe but is found across North America.
- Southern yellowjacket (Vespula squamosa): yellow and black, found in the south.
Nests and Feeding
Understanding the lifecycle and colony behavior is vital in tackling an infestation or avoiding them while working in the garden.
Every colony is intrinsically interconnected and works together.
Typically, yellowjackets build nests in trees, underground, inside walls, and cavities within buildings. They build nests in attics and under decks. Their preferred area depends on the species.
Due to their gregarious social behavior, nests can be large, housing thousands of individuals. The number of yellowjackets in a nest can vary from 500 to 4,000, even more, if conditions are favorable.
Nests are made from chewed-up wood and layered to form intrinsically patterned cone-type domes with hexagon cells for the young.
Yellowjackets are predatory insects, feeding on spiders, insects, and sometimes small vertebrates. As scavengers and opportunistic feeders, they won’t pass up an easy meal. That’s why you’ll find them hovering when you eat meat outdoors.
They’re also drawn to sweet substances such as fruit, flowers, vegetables and kitchens.
The Yellowjacket Lifecycle
The lifecycle of yellowjackets begins in springtime when new female queens emerge from overwintering.
Egg Stage
Yellowjacket queens will start the colony by building cells, laying eggs, and caring for the young.
The eggs hatch in about 20 days, and all the first eggs are infertile females known as workers. These workers take over the nest-building, foraging, and caring roles, allowing the queen to remain in the nest to focus on population growth.
It is only when the seasons roll into fall that the queen lays eggs that will become males (drones) or fertile females (new queens).
Larval and Pupal Stage
Larvae are legless grubs. The workers feed them a mixture of protein and sweet substances.
Yellowjacket wasp larvae go through five molts as they grow. It can take up to 15 days before the chamber is sealed with silk and the larvae commence pupation.
Pupae undergo a dramatic transformation. Over a period of eight-18 days, they seal up in one of the nest chambers inside a hard, brown shell.
The chambers stay sealed to ensure a successful metamorphosis. Once they’ve pupated, a fully formed adolescent wasp will emerge.
Adolescent Stage
Female wasps are the main offspring that emerge at the beginning of the season. This is because they are the workers, supporting the colonies’ growth, feeding the young, protecting, and cleaning up.
The queen releases a pheromone, which blocks the worker’s ovary development. If the queen dies workers will start to develop the ability to lay.
In adolescence, they remain at the nest to tend to the new young. Once they have matured, they leave to become the providers of water and food.
Adult Stage
Worker yellowjackets have a unique digestive system, which makes them dependent upon the larvae and colony.
Although they hunt insects and spiders, they can only chew the particles and are unable to digest them. The chewed substance is fed to the larvae.
In turn, the larvae secrete a sweet sap that feeds the workers. This is why yellowjackets are addicted to sugar. It’s a way to ensure that they care for the larvae.
Before the mature adults die, female workers return to the nest and assist with the larvae’s care, passing on their knowledge to the adolescents. Female workers are estimated to live up to three weeks.
Fertile females and males are laid near fall, before egg-laying stops for winter. Once mated, the males die, and the new queens overwinter until spring, when they will continue the colony’s legacy.
At the end of the season, in late fall to early winter, the colony dies off except for the mated new queens, which hibernate until spring.
In warmer regions, when winter temperatures remain above freezing, she may remain in the nest. In colder regions, the nests are abandoned each fall, and new ones are started in spring.
Why Yellowjackets Are Beneficial
Yellowjackets are often misunderstood, but they actually play a vital role in a healthy garden environment.
1. Pollination
Since they look like bees and like nectar, it shouldn’t come as a surprise that yellowjackets actively pollinate flowers, moving from plant to plant foraging.
The workers are responsible for pollinating trees, shrubs, and herbs that provide us with flowers, fruits, and vegetables.
2. Pest Control
As predators, yellowjackets actively seek out and destroy some of the most troublesome garden pests. Caterpillars, crickets, cabbage worms, beetles, grubs, aphids, flies, and a rang e of other annoying creatures.
By feeding on harmful species, yellowjackets help the ecosystem balance and reduce the requirement for chemical pesticides.
3. Composting
Yellowjackets play a role in the decomposition of organic matter. As they scavenge for food, they consume decaying plant material and animal remains, helping to break down these materials and return valuable nutrients to the soil.
This process enhances the vibrance and fertility of the garden, supporting the growth of healthy plants.
Why Yellowjackets are a Pest
There are not many who haven’t been stung at some point in their lives—at a picnic, the beach, during a BBQ, at the playground, while picking fruit, or minding their own business in the garden.
Here’s why you might want to keep yellowjackets away.
1. Swarming
As a protective response to a colony being threatened, yellowjackets will swarm together to defend the nest.
Yellowjackets attack by funneling en mass out of the hive entrance. They will attack the threat, stinging repeatedly.
For those who are allergic, this can be a medical emergency. But even those who aren’t allergic can be stung repeatedly, which can rapidly become a serious medical issue.
Yellowjackets are even more aggressive in the fall.
2. They Kill Beneficial Creatures
As they hunt in the garden, yellowjackets will also target beneficial insects like bumble bees, honey bees, and butterflies. They’re indiscriminate in finding a meal.
Garden and farm beehives are at risk, mainly in the fall. When wasp larvae numbers drop off, so does the sweet sap food substance the adults rely on. Beehives with honey are a built-in feast. So are hummingbird feeders and yellowjackets will attack visiting birds.
The onslaught of yellowjackets on beehives weakens them significantly and can destroy them.
3. Living In Human Structures
Should a yellowjacket hive infiltrate a home or structure, it can damage the materials. If it grows to a substantial size, they even may build their nests in walls, attacks, and insulation. They frequently build nests attached to the eaves of homes.
If you’ve ever had a nest built near a doorway, you know it can be an incredible nuisance.
Cohabiting in this way can be disconcerting, interrupt your normal daily routines, and create a real worry. No one wants to share their h some with aggressive, stinging insects.
4. Stings
The most obvious downside to yellowjackets is their sting. Unlike bees, wasps can sting numerous times. They don’t lose their stinger after they inject it into you.
Bees have barb-like structures that get stuck when they sting, removing the stinger from their bodies, and causing abdominal collapse and death. Wasps stingers have no barbs and can pierce the skin numerous times.
By retracting the stinger and using its abdominal muscles, the yellowjacket can keep the venom flowing. This is a particular issue for those allergic to stings or those with significant health issues.
When they sting repeatedly, they inject a protein into the body, which can cause tissue damage.
Yellowjackets are reactive and fiercely protective. Their tendency to sting is usually provoked when they or their nests are under threat.
Control and Management
Because of their nesting behavior, yellowjackets often remain undetected until the colony reaches a massive size or they’re mistakenly disturbed. You might even come across a giant nest with active yellowjackets hanging around it.
Identifying the specific species of yellowjacket will help you determine where they nest, the risk of swarming, and how best to deal with them. If you can, find an already dead one, take a picture and use the internet to search for the species.
Regardless, you can deal with them in the same way.
1. Spray
Use a targeted spray on the nest and individuals. Make sure people keep a good distance away and spray at dusk when most of the yellowjackets are in residence.
Spraying late in the day may mean the nest occupants are more docile, but you must use caution. If you start spraying and the yellowjackets attack, they will sting you to protect their home.
Wear protective clothing and follow the manufacturer’s directions exactly. Grab Wondercide Killer in a two-pack of ten-ounce sprays at Amazon.
If the nest is a large one, it’s best to call an expert.
2. Traps
There are traps available that tempt the workers into a funnel-like device. Once in, they can’t escape.
Although this will assist with reducing numbers, a combination of control methods may be required in the case of a large infestation.
Grab a pack of three traps with included attractant at Amazon.
You can also use electric traps, though these are less effective on yellowjackets.
3. Protect Beehives
If you have honeybees, purchasing hive guards and patrolling your bee area in late summer early fall is a smart plan. Taking the beehive’s entrance down to one entrance in and one out or using a guard at the entrance will help your bees fend off any attacks.
4. Protect Food Sources
Protect food when cooking outside by using covers. Avoid letting people, especially children, have cans of fizzy drinks. Yellowjackets can enter the cans only to sting any unsuspecting person drinking from it.
Feed pets in a safe place and remove any uneaten food.
5. Inspect and Clean
Make sure to survey your land and buildings for nest sites regularly. Remove or cover any area that may become one, such as fallen trees, debris, rubbish bags, and any untreated wood.
If you collect firewood throughout the year, it’s good practice to check for hibernating queens before taking wood inside.
House maintenance and hygiene practices should be carried out all year round. Seal any gaps in the house to prevent access the attic space or wall cavities.
Keep large plants away from the external walls and any entertaining areas, as this provides cover for the yellowjackets.
6. Call an Expert
If in doubt, call an expert. Weigh the risk of harm or problems before you tackle a nest on your own and you might find that having experts out is the way to go.
Nests in the ground are harder to determine size-wise. If one is located and it’s not in a good spot, carefully mark its location and call a professional.
