What’s buzzing around California? It’s not bees or mosquitoes, it’s wasps. Active year-round, wasps are most noticeable from March through November. This peak season sees their colonies at full size, leading to increased foraging behavior around food sources.
Californias warm climate supports a lengthy wasp season, with common species including yellowjackets, paper wasps, and hornets. During these months, wasps are more prevalent, making it essential to exercise caution around their nests and manage potential attractants.
“This is a really big year for wasps,” Lynn Kimsey, director of the UC Davis Bohart Museum of Entomology, told the Sacramento Bee.
California is home to over 30 species of wasps. While some are relatively harmless, others can pose a serious sting risk. This guide covers how to identify common California wasps, their habits and habitats, and how to stay safe around them.
What Makes a Wasp a Wasp?
Before identifying specific species, it helps to understand what defines a wasp. Wasps are distinguished from other stinging insects like bees by their narrow waists and smooth, hairless bodies. They have two pairs of wings and chewing mouthparts for eating other insects.
Unlike bees, wasps are predatory and do not produce honey. Only female wasps have a stinger, which they use to paralyze prey and defend their nests. Wasps can sting multiple times.
Most Common Wasps in California
Here are some of the wasps you’re most likely to come across in the Golden State
-
Western Yellowjacket These familiar black and yellow striped wasps have nests underground and scavenge food at picnics and outdoor events They aggressively defend their nest and readily sting,
-
European Paper Wasp Longer and thinner than yellowjackets, these are also black and yellow. They build aerial nests and are common around homes and gardens.
-
Mud Dauber: Named for their mud nests, these have a black body and yellow legs. They prey on spiders to provision their nests.
-
Sand Wasp: Large solitary wasps that dig burrows and stock them with paralyzed insects. They frequent sandy areas and are not aggressive.
-
Tarantula Hawk: Among the largest wasps at over 2 inches long, the female tarantula hawk hunts tarantulas as food for her larvae. Her sting is extremely painful but these wasps rarely sting.
When and Where to Find Wasps
-
Yellowjackets, paper wasps, and other social species form colonies that grow over the warm season, reaching maximum size in late summer and fall before dying over winter. New queens emerge to start the cycle again in spring. Solitary wasps are active whenever prey is available.
-
Look for aerial paper wasp nests under eaves and ledges of buildings. Yellowjackets frequent picnic areas and build underground nests but may also nest in wall voids or trees.
-
Mud dauber and sand wasps inhabit bare soil areas. Tarantula hawks live in deserts and grasslands. Gall-making wasps are found where host trees like oaks grow.
Wasp Behavior and Habits
-
Social wasps like yellowjackets live in colonies with queens, workers, and males. They defend the nest aggressively.
-
Solitary wasps live alone. The female builds a nest and provisions it with paralyzed insects or spiders as food for her offspring when they hatch.
-
Male wasps do not have stingers and focus solely on mating. Only females can sting.
-
Wasps are predators and scavengers. They kill and eat other insects, spiders, caterpillars etc. Some also scavenge human foods for sugar.
-
Parasitoid wasps like tarantula hawks paralyze prey to serve as hosts for their offspring rather than killing them outright.
Avoiding Stings and Staying Safe
-
Do not swat at or provoke wasps, especially around the nest. Remain calm and still and move slowly away.
-
Avoid wearing strong perfumes or scented lotions that may attract wasps.
-
Check for nests around your home and have them removed professionally. Seal holes and repair damaged eaves.
-
Wear shoes outdoors as ground-nesting wasps may sting if stepped on. Be careful around flowering plants.
-
If a wasp approaches your food, calmly cover it or move it away rather than swatting.
-
If stung, remove the stinger by scraping with a credit card or using tweezers. Apply ice and antihistamine cream. Seek medical help for multiple stings or if you have allergies.
Identifying California Wasps
Learning to recognize key species by sight is useful both for avoiding problematic ones like yellowjackets and appreciating the diversity of wasps in California. Focus on markings, size, and nesting habits to tell them apart. With care and respect for their space, you can safely enjoy the outdoors with these fascinating insects.
What makes a wasp sting you?
Wasps sting primarily as a defense mechanism; several factors can trigger this response. One of the most common triggers is a perceived threat to their nest.
According to ScienceDirect, an online database for accessing scientific research, wasps release alarm pheromones when they sting or feel threatened. These pheromones can alert other wasps and trigger a coordinated defensive response, leading to multiple stings.
Handling a wasp or swatting at it can further provoke a sting, as wasps may feel threatened when directly confronted. Vibrations near their nests, caused by lawnmowers, construction equipment, or loud noises, can disturb wasps and lead to a defensive sting. Certain species, like yellowjackets and hornets, are more aggressive and quicker to sting in defense of their colony than solitary wasps, which are generally less aggressive.
What should I do if I’m stung by a wasp?
According to the National Institute for Occupational Safety and Health, if you are stung by a wasp, have someone check you for an allergic reaction. Wash the site with soapy water and remove the stinger with gauze or a fingernail. Do not squeeze or use a tweezer where you were stung. Apply ice to reduce swelling, and do not scratch the sting as this may increase swelling, itching, and risk of infection.
The Magical Jumping Wasp Galls of Chico, California
FAQ
What is the most common wasp in California?
- Yellowjackets: These wasps are more aggressive and can be a nuisance, especially around food and garbage. …
- Paper wasps: These wasps are often seen building umbrella-shaped nests under eaves, in attics, or in other sheltered areas.
Why are there so many wasps this year in California?
When temperatures become too hot, wasps can be found in shaded areas or near damp places. Hot weather could increase the number of yellowjackets and other wasps in California. Lawns, sprinklers and insects attract the predatory wasps.
What is the California killer wasp?
Pacific cicada killer (Sphecius convallis) is the largest wasp in California. Body length is about 1.5 in. long. Though they can sting humans, it is very rare and not generally a concern.
Are mason wasps aggressive?
This species is solitary and not aggressive. It can be found in gardens and other open areas. Adults feed on flower nectar.
Are there wasps in California?
The wasps you find in California have almost yellow metasoma with restricted black. This is a social wasp, which creates nests in sheltered locations, including near man-made structures. In California, the adults are more common from January to November. 10. Beaked Twig Gall Wasp
Where do Western paper wasps live in California?
Western Paper Wasps live in California in forests, suburban neighborhoods, and urban areas near a river or stream. They move along these river and stream openings when they’re out foraging for insects and nectar and collecting fibers to build their nest. They also gather water and take droplets back to the nest to cool it during hot weather.
Do paper wasps sting in California?
California is home to 22 species of paper wasps. Depending on the species, the sting of the paper wasp ranks between 2-3 on Schmidt’s index. The sting of the coarse-backed red paper wasp (Polistes Carolina) is rated as a 3.0, which is considered severe.
What types of wasps live in western states?
In Western states there are two distinct types of social wasps—yellowjackets and paper wasps. Yellowjackets are by far the most troublesome group, especially ground- and cavity-nesting ones such as the western yellowjacket, which tend to defend their nests vigorously when disturbed.
Are wasps pests?
Yes, wasps can be pests. The pestiferous wasps are members of the Vespula vulgaris group, which have nests with peak wasp population numbering in the several thousands and they continue their life cycle well into the late autumn. Although they do collect insect prey, they also scavenge meat which puts them into contact and conflict with humans.
How many species of wasps are there?
There are over 100,000 described species of wasps, with many more yet to be discovered and classified. Wasps vary greatly in size and shape. There are tiny parasitic wasps that are less than an inch long. There are also intimidating-looking hornets that can reach several inches in length.