Currently viewing the category: "Thread Waisted Wasps"
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Subject: What is this nest?
Location: Top of an outdoor window
July 9, 2017 10:34 pm
I live in Scottsdale, AZ and this nest was not here yesterday. What is it and should I leave it alone? I’m vegan so I will only rid it if it is dangerous! Thank you!
Signature: Tina

Mud Dauber Nest

Dear Tina,
This is a Mud Dauber Nest, the nest of a non-aggressive, solitary wasp, probably the Black and Yellow Mud Dauber, that is often found near sprinklers and swimming pools where it gathers mud with which to construct its nest.  It appears your nest is at the beginning stages of construction.  Eventually, the female Mud Dauber will add additional chambers and each will hold a developing larva and the paralyzed spiders that will provide its food supply.

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Subject: A nest of grasshoppers??
Location: Ontario Canada
July 8, 2017 10:30 am
We opened up our window on the second storey of our home and found this nest filled with these light green insect resembling a grasshopper. I didn’t think that they made nests so I’m not sure if my assumption is correct or how they would even get there. Any info would be really appreciated.
Signature: Thanks for any info.

Grass Carrying Wasp Nest

This is the nest of a Grass Carrying Wasp.  The female Grass Carrying Wasp constructs her nest and provisions it.  According to BugGuide:  “Larvae are fed Gryllidae (particularly tree crickets) or other Orthoptera.” 

What's That Bug? does not endorse extermination

Subject: Mud Dauber Exhibitionists
Location: North Las Vegas NV
June 1, 2017 1:46 pm
It’s the beginning of Summer here in Las Vegas NV and as I was going back into the shop I spotted a small orgy.
Not sure what that top male thinks he’s doing, but I’m sure everyone is having a good time!
Signature: Unintentional Voyeur

Black and Yellow Mud Daubers Mating

Dear Unintentional Voyeur,
Apparently, multiple male Black and Yellow Mud Daubers competing for the same female is not unusual behavior as this image from our archives illustrates.

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Subject: Pretty metallic blue insect
Location: Blackwater National Wildlife Refuge, Maryland
May 27, 2017 3:56 pm
Saw this beautiful critter land on a leaf at Blackwater National Wildlife Refuge on Maryland’s eastern shore. Thought at first I had a six-spotted tiger beetle, but the color and the wings seem wrong for that. What do I have here?
Signature: Rob Nease

Steel Blue Cricket Hunter

Dear Rob,
This beauty is a Thread-Waist Wasp in the family Sphecidae that is commonly called a Blue Mud Wasp or Blue Mud Dauber,
Chalybion californicum.  According to BugGuide:  “Females construct mud nests in sheltered areas, often under the eaves of buildings, and provision them with spiders. Sometimes refurbishes the nests of other mud-daubers, such as Sceliphron.”

What's That Bug? does not endorse extermination

Subject: Is this an ichneumon wasp?
Location: Austin, TX
April 30, 2017 8:49 am
What is this bug? Finding them inside the house this spring trying to get out…hanging around the windows…do they sting/bite? Any house structure damage concerns?
Signature: Stephen

Grass Carrying Wasp

Dear Stephen,
Based on BugGuide images, we are pretty confident that this is a Grass Carrying Wasp,
Isodontia mexicana.  According to BugGuide:  “Taken from the Internet Reference below (Penn State): The adult wasps emerge from their cocoons in early summer, mate, and the females locate a suitable nest site. She collects blades of grass and grass and hay stems to line the nest cavity. The wasp can be seen flying through the air with the blades trailing beneath her. She lands at the hole and enters, pulling the blade in behind her. After the nest is prepared, she hunts for tree crickets (i.e., Oecanthus sp.), captures and paralyses them with her sting, and transports them to the nest. She deposits eggs in the nest and the emerging larvae will feed on the living, but immobile crickets. When the larvae reach the appropriate size (in 4–6 days at 70–75° F.), they spin a cocoon and pupate. The adult wasps emerge in 2–3 weeks. In Pennsylvania, Isodontia mexicana typically produce two generations per year.  Remarks These wasps commonly make their nest in the narrow track found above outer windows.”  We have many more images in our archives of the nests of Grass Carrying Wasps because they are so frequently found in window tracks.  Solitary wasps are generally not aggressive, and rarely sting humans, though that possibility does exist.  Since they are harmless, and since it appears one individual in the images you attached might be dead from unnatural causes, we are tagging this submission as Unnecessary Carnage.  Because Grass Carrying Wasps are emerging from nests formed in window tracks now that spring has arrived, and because we suspect other homemakers might be experiencing similar sightings, we are tagging this posting as the Bug of the Month for May 2017.

Grass Carrying Wasp

Update:  Grass Carrying Wasps reported from France
Subject: Grass carrying wasp
July 25, 2017 5:29 am
Looking at your excellent site, I think you may have resolved two mysteries for me.
We have noticed recently a number of ‘grass carrying wasps’ around our dining table on the terrace. They have been disappearing into the metal frame taking their blades of grass with them. However, without taking the table apart we have been unable to tack where they are going.
I assumed them to be carrying the grass for nesting material and your site confirms this.
What you may have also answered is the reason why over the past couple of weeks, we have been finding a number small, bright green crickets on the chairs and the terrace around the table. Anything from 1 to about a dozen or so at any one time.
We assumed them to be dead but your item on the  g.c.w. suggest that may not in fact be the case.
If I may ask a question – we live in the south-west of France which is a long way from you folks. Can you confirm if these wasps are the same i.mexicana as you have or another entirely different insect altogether.
Many thanks for creating and maintaining the website. I use it often.
Have a nice day y’all.
PS – If I can get a decent photograph I will send it to you.
Signature: Robin Nichols

Dear Robin,
We sometimes have a hard time with French sightings as there are not many comprehensive insect websites devoted to French species, however, folks in the UK seem to really like their bugs.  According to the Bee Keepers Garden:  ” A new to Britain wasp,
Isodontia mexicana (de Saussure), known as the Grass-carrying wasp, has been discovered at Greenwich Peninsula Ecology Park. …  Researcher David Notton of the Natural History Museum said the wasp is pretty docile and a solitary species, so does not form large nests. ‘It’s quite unlike the better known and aggressive yellow/black social wasps with which people may be familiar.  We don’t know how it got to the UK, and although it’s a non-native invasive species there’s no evidence to suggest it’s a threat to UK fauna.'”  Since the Grass Carrying Wasp has been reported in the UK, it might have also been introduced to France.  According to Encyclopedia of Life:  “Isodontia mexicana, the grass-carrying wasp, is one of the thread-waisted wasps belonging to the family Sphecidae. It is native to North America, found east of the Rockies and through Central America, but has recently been introduced into France, where its population is slowly spreading through Europe.” 

Good morning Daniel,
Many thanks for your reply regarding the grass carrying wasp. I have since looked on the internet for information regarding the existence of the insect in France.
According to a (French) Wikipedia entry the wasp arrived in southern France sometime during the 1960’s, since which time it has spread throughout the Midi region (effectively the southern half of France) and is now present in Italy, Spain and Switzerland.
Helped, it is believed, by the long, countrywide heatwave in 2003, it managed to traverse the Massif Central into more northerly parts of France and is gradually spreading further north – presumably as global temperatures rise. I
As you say, it has now also been found in the UK.
Kind regards

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Subject: what is going on with these wasps
Location: near houston
April 28, 2017 9:56 am
very odd. 4 wasps on top of each other. At first ii thought it was a multiple mating, but It appears that the bugs on top are dead. What is going here? what sort of wasp is this? is this normal? i’ve never seen this before.
Signature: jay in texas

Mud Dauber Mystery

Dear Jay,
We wish you had been able to provide better quality images.  While there is enough detail to determine that these are Black and Yellow Mud Daubers,
Sceliphron caementarium, and it appears they are “attached” to one another at the head like each was biting another at the “neck”, we cannot fathom what is going on or what happened.  It is interesting that you observed the the ones on top are dead.  Does that mean the ones on the bottom were alive?  It also appears that they are on a collapsible hose, which makes sense since Mud Daubers are often found near puddles that occur when watering or near swimming pools.  You may verify our identification by comparing your individuals to this BugGuide image.  Mud Daubers are solitary Wasps, and each female makes and provisions her own nest, so this “group activity” is quite puzzling.  We will contact Eric Eaton to see if he can provide a hypothesis on what is happening.

Update:  Supposed Mating Behavior
Thanks to Cesar Crash who provided comments with links to Shutterstock and BugGuide.

Eric Eaton Confirms
….Three males competing for a female (bottom-most individual).  The neck-grabbing is typical male mate-guarding behavior, or attempt to mate.
author, Kaufman Field Guide to Insects of North America

What's That Bug? does not endorse extermination