Did you find cocoons in your window frame? Most probably, you encountered the pupae of grass-carrying wasps. But are grass-carrying wasps dangerous or beneficial? Let’s find out.
Have you ever noticed strands of dry grass on the corners of your windows?
While these might look like nests of some random pest, they are the home to one of the most beneficial insects from the wasp family, the grass-carrying wasp.
Primarily found in the regions of the northern United States, these wasps offer great assistance to gardeners and farmers.
Wondering how? Read this article to learn all about grass-carrying wasps and how they are beneficial.
What Are They?
Before we dive into the details of this topic, let us first understand what a Grass carrying wasp is.
They are gentle solitary wasps who prefer to nest aboveground in a preexisting cavity like the tracks of storm windows or hollow plant stems.
Grass-carrying wasps are around 0.7 inches long with a pair of smokey red-tinted wings. Their black bodies are lined with long and thin abdomens. If you look closely, you can find some white hair on their thorax.
Females build nests using grass blades where they feed and nurture the larvae. These larvae are grub-like and have no legs. You can identify them by the yellow-cream color of their body.
What Do They Do?
These wasps spend most of their life-cycle pollinating flowers and sucking nectar, except when the female wasps are engaged in building and provisioning nests.
Females carry blades of grass to where they build the nest. Using strands of dry grass blades, they make brood cells. These cells are filled with dead tree crickets for the larvae to feed on.
Once these larvae reach the final stage of development, they create cocoons and transform into pupae and later emerge as adults during spring.
The nesting season starts early in July, followed by adults visiting flowers by late July throughout September.
Are They Dangerous?
Unlike most thread-waisted wasps, the grass-carrying wasps are not aggressive, and they don’t aggressively defend their nests.
They don’t sting anyone other than the tree crickets and their other prey. If you find wasp nests in your storm windows, make sure you remove them gently.
Remember, these wasps can sting but are harmless until you try to handle them.
Are They Beneficial?
Grass-carrying wasps are considered highly beneficial. Farmers and gardeners often make efforts to lure them into nesting in their gardens. Here are the two most helpful features of a grass-carrying wasp:
They are excellent pollinators
Since these wasps spend most of their time collecting nectar from flowers, they carry pollens from one flower to another to facilitate the growth of new plant seeds.
In many cases, These wasps have a particular affinity toward white flowers and tend to visit them more often than the others.
They eliminate pests
Apart from being great pollinators, these wasps are excellent for pest control. Grass-carrying wasps are highly-skilled predators.
The Females are experts in hunting down tree crickets and other pests. They sting these herbivorous prey to paralyze them.
After that, they store the paralyzed prey in the nest so that the growing larvae can feed on it.
How to Attract Them to Your Garden
Provide a nesting place
As mentioned above, these wasps don’t build their nest in excavated underground burrows; they prefer to nest aboveground in certain cavities.
They usually prefer natural cavities like hollow plant stems or a hole in a wooden log.
Therefore you can place some freshly cut hollow stems in your field. Make sure these stems are at least 10-inch length and placed horizontally above ground.
You can bundle a few of these hollow stems together with burlap twine to increase the nesting chances.
Maintain a pesticide-free yard
A yard or garden full of pesticides is a significant obstacle to attracting pollinators.
Under no circumstances will an insect feed on a flower sprayed with insecticides over pesticide-free ones.
To attract grass-carrying wasps refrain from using insecticides in the garden, particularly on flowering plants.
A good dump of dry grass strands will also attract these wasps as they depend on these strands to build nests.
Frequently Asked Questions
Are wasps pests or beneficial insects?
Grass-carrying wasps are highly beneficial insects as they are excellent pollinators. These wasps are less aggressive to humans and great hunters of pests like tree crickets.
Farmers and gardeners try to lure these wasps into nesting in their fields to increase pollination and eliminate pests.
Do digger wasps have a queen?
Digger wasps are a common species of the wasp family. But unlike other wasp species, they live in and nest alone.
These wasps don’t have a queen and can be considered a solitary species. Being a solitary species, they don’t show aggressive behavior towards humans if not disturbed.
What kind of wasps digs holes in the ground?
Cicada killer wasps, also known are ground digger wasps live in the ground in tiny holes and prey on cicadas for food.
These wasps are solitary species and are generally not aggressive towards humans. They are amongst the most giant wasps and are primarily black, with yellow stripes on their abdomen attached to translucent orange wings.
Does killing a wasp attract more wasps?
Killing a wasp is not the best way to get rid of these insects. When you kill a wasp, it releases pheromones that attract other wasps nearby.
So instead of killing one, calmly trap the wasp under a glass. This is called a wasp trap, preventing the trapped wasp from returning to the nest.
Wrap Up
Grass-carrying wasps are highly beneficial insects, but unfortunately, many people don’t understand their importance and misunderstand them as highly aggressive pests.
We sincerely hope that you are able to understand the importance of these creatures after reading about them. Thank you for reading!
2 Comments. Leave new
I use to just have one or two windows, today, I had these little green ugly kadydids in straw in bedroom windows only one side, north windows and even in my kitchen window, dinning room and living room, they are everywhere. I did notice so many crickets this year while gardening. I just get a kitchen knife clean out the window side pane and kill them. How to get rid of them permanently. I hate these critters, they (some) of them turned into magots . ( ugh)
This is cool — I just found similar nests with paralyzed katydids – but in the pipes of some wind chimes (I was cleaning them because the chimes didn’t sound right!) I was a little worried about what I might find. I found a few larva and cocoons and didn’t know what they were until I found an old cocoon that I opened and found a fully formed, small, wasp in it! The chimes were packed with grass nearly 4-5 inches worth. I was glad to see “someone” was helping with the katydid population, so I won’t disturb them further. I’m in the East Bay area of Northern California. I guess these wasps are wide-spread!