Grass-carrying wasps are common across America, and if you have seen one, you might get intimidated by them. But does a grass carrying wasp sting? We looked it over, and here’s what we found.
Grass-carrying wasps (Isodontia) come from the thread-wasted wasp family Sphecidae.
These wasps are beneficial in the garden and only sting if provoked or threatened.
They are not threatening or aggressive and usually do not cause humans any trouble.
Except for the nuisance of their nests made from dry grass, which ends up on window frames, there is no reason to want to get rid of them.
Continue reading if you want to learn more about these unique and interesting creatures.
What Is This Bug?
The adult wasps of this species are around 7/10th of an inch long with black bodies and red-brown wings.
Their narrow waist connects their abdomen to the thorax. The thorax is covered with white hair. Their larva is grub-like, cream-colored, and legless.
Grassy carrying wasps are solitary wasps that live above the ground (unlike mud daubers or digger wasps). They usually come out of their cocoons during July and August.
During this time, they visit flowering plants for nectar. Female wasps collect tree crickets and katydids to provide food to their larva.
The females also collect blades of grass to make a nest for their larvae. These nesting sites are made in wood cavities, hollow plant stems, bee nests, and human window frames.
These wasps either create individual brood cells partitioned with blades of grass or build a common nest area where multiple larvae can feed and grow.
There are several species of grass-carrying wasps, but Isodontia Mexicana is the most common in the United States.
Homeowners typically come face to face with the nests of this wasp when they are replacing their window screens with storm windows in preparation for the coming winters.
Does It Sting?
It is pretty unlikely for a grass wasp to sting you since they are usually unbothered by human presence and don’t defend their nests.
However, this black wasp may sting you if it feels threatened or provoked, and their sting does carry a punch, so it is best to keep a safe distance from them and just watch them from afar.
Is It Venomous?
Yes, a grass-carrying wasp is venomous, but the venom is harmless to humans. The wasp uses its venom to prey on tree cricket and smaller insects.
Like many parasitoid wasps, they paralyze their prey and leave them near the larvae in their grassy nest. They do not use their venom upon anyone else except for their prey.
Is It Aggressive?
These wasps are not known to be aggressive. They wouldn’t even defend their nests from breaking, and if you remove the nest, they often won’t rebuild it in the same spot.
The good thing is that grass-carrying wasps are non-social and, thus, do not live in colonies. So, you can quickly get rid of their nests if they annoy or irritate you.
What Should You Do If You Get Stung?
Even though grass wasps do not sting humans, they may break their habit once in a while. So, here are some things that you can do if you get stung.
- Remove the stinger with a tweezer or credit card.
- Apply an ice pack to the affected area for at least 20 minutes
- Wash the area with soap and water and apply hydrocortisone cream to it
- Take an antihistamine, like Benadryl, to get rid of itching or swelling
- In case you are in pain, take acetaminophen (Tylenol) or ibuprofen (Motrin)
- If you haven’t taken a tetanus booster for more than ten years, it is advisable to take one in the next few days
In most cases, a sting from a grass-carrying wasp wouldn’t hurt unless you are allergic to insects.
In that case, it is best to follow the above steps and seek medical help if the symptoms start to get worse.
What Does It Feed On?
When it comes to food, the adults and larvae have different preferences. While the adults like to drink from certain native flowering plants, the larvae need insects to grow and develop.
These insects contain protein which is important for the growth and development of the larva.
Larvae
Unlike adult grass wasps, larvae feed on tree crickets and insects from the family Gryllidae.
The female wasps collect tree crickets, katydids, caterpillars, and other similar insects from gardens and take them to the ‘nursery’ of their larvae.
The larva will carefully feed on the insect, first sucking out the juices and then feeding on the remaining body parts, leaving the heart and nervous system for the last.
This is to ensure that the larvae always get a fresh meal!
Adults
The adult wasps, on the other hand, feed on the nectar from flowers of native plants. Like other wasps, they, too, have a preference for plants with white flowers.
They get energy from their nectar, especially the females, who need it to hunt and take the food to the nests.
While feeding on the nectar, the pollen from these flowers also gets stuck between their legs, and they act as excellent pollinators by depositing the pollen in far-off places.
Are They Harmful Or Beneficial?
These wasps are beneficial insects who visit a variety of flowers to drink nectar and therefore contribute to plant life as pollinators.
Besides, they also hunt and prey on garden insects like tree crickets and others from the Gryllidae family and help keep your garden and parks clean.
Probably the only harm these wasps can bring you is that they can build cocoons in the cavities of wood, including the frames for your storm windows.
Also, if you are allergic to insect bites, their sting may cause problems.
Frequently Asked Questions
What attracts wasps to sting you?
Wasps are usually attracted to flowers or prey. They may sting you mistakenly while you are handling flowers, but it is pretty rare.Â
In your presence, they may sting you if they feel threatened or their nest seems to be in danger. Thus, it is for the best to avoid being around their nests.Â
Do wasps make nests in the grass?
Wasps usually build their nests in trees, but some may nest inside burrows that they build in the ground.Â
The nests of grass-carrying wasps, however, are made in wood cavities, abandoned insect nests, and plant stems.Â
Do wasps live in the grass?
Wasps usually live in and around grass because many of them hunt garden insects.Â
Many also feed on flower nectar, honeydews, food, and other sugary substances. Thus, you might often find wasps hovering over lawn grass.
Grass-carrying wasps use blades of dry grass to make nests for their larvae, so these wasps are often found near the grass.
What are the wasps that hover over the lawn?
Blue-winged and grass-carrying wasps are two of the many wasp species that hover over the lawn for food and prey.Â
Both feed on sugary substances and use paralyzed prey to feed their larvae.Â
Grass-carrying wasps need grass blades to make their nests. Blue-winged wasps lay their eggs on grubs and therefore are often found hovering near the ground.
Wrap Up
So, to answer the question- yes, grass-carrying wasps can sting you if you try to mishandle them.
But otherwise, these little guys are very non-aggressive and don’t come in our path for any reason whatsoever.
They simply lead their lives preparing nests for their young ones and sucking nectar from flowers.
They are not even big on defending their carefully prepared nests. If you find and break their nest, they would simply stop making one in that location since they would see it as a sign that the location is unsafe.
Thank you for reading!
6 Comments. Leave new
Most Wasps seem to have a similar plan. Nesting site could be of different kind.
some use crickets while some use caterpillars……
Thanks for your reply. I feel bad that you took time out to do so though. I certainly understand how busy you are and was not prodding – I was just so happy that I figured it out! I’m glad that you could use the photo. Thanks again for everything 🙂
The posting has already generated two comments other than your own, so it is obviously of interest to our readers. We are thrilled to have your image as part of our archives.
I have these great black wasps. They have been nesting in my windows for years. Google it and now I know. But why do I find them only in the right of my window. Should I call them the right side great black wasp?
Grass carrying wasp, in My vinyl siding , Massachusetts. Thank You 4 the info. I also will let it bee. LOL