Scarab Hunter Wasp: Quick Facts for Enthusiasts

The fascinating world of insects includes a diverse array of species, and among them is the Scarab Hunter Wasp. Known for their unique appearance and intriguing behavior, these solitary wasps have become a topic of curiosity for many.

Scarab Hunter Wasps primarily belong to the thread-waisted wasps (Sphecidae) and digger wasps (Crabronidae) families. They vary in size, ranging from less than 1/2 inch long to 1-1/2 inches long, with slender to stout bodies. These wasps exhibit various colors like black and yellow, or black and other shades, making them visually captivating creatures.

Apart from their striking looks, these wasps play a significant role in controlling scarab beetles, which can cause extensive damage to plants. So, by learning more about Scarab Hunter Wasps, you’ll not only satisfy your curiosity but also gain an appreciation for their ecological importance.

Identification and Characteristics

Physical Features

Scarab Hunter Wasps are fascinating insects belonging to the order Hymenoptera. They are large arthropods known for their striking appearance. Some notable features of these wasps include:

• A prominent abdomen
• Two pairs of wings
• Short antennae

In particular, the Yellow Scarab Hunter Wasp is known for its vibrant coloration. This species displays a beautiful, bright yellow color with black markings on its body.

Types and Species

There are several species of Scarab Hunter Wasps, which belong to different subfamilies within the Scoliidae family. Some examples include:

• Scoliid Wasps: These are generally large and hairy, often seen hovering around flowers or lawns.
• Campsomerinae: A subfamily consisting of several species, such as the Dielis genera.
• Dielis pilipes: Also known as the Yellow-legged Scarab Hunter Wasp, it is well-known for hunting scarab beetle larvae.

Here’s a quick comparison of two species within the Scoliidae family:

By understanding the physical features and types of Scarab Hunter Wasps, you can easily identify these unique insects and appreciate their role within the ecosystem.

Life Cycle and Reproduction

From Egg to Adult

The life cycle of a Scarab Hunter Wasp is fascinating. These solitary wasps go through several stages, including the egg, larval, pupal, and adult stages. When a female wasp finds a suitable host, such as a scarab beetle larva, she lays her egg on or near it. This is necessary because the wasp larva will eventually feed on the beetle larva.

While the wasp egg is developing, the host remains alive, ensuring a fresh food source for the emerging wasp larva. Upon hatching, the wasp larva begins consuming the beetle larva, eventually killing it. Once the host is consumed, the wasp larva spins a cocoon and enters the pupal stage.

During the pupal stage, the wasp larva undergoes a metamorphosis, transforming into an adult Scarab Hunter Wasp. This process takes a variable amount of time, depending on the species and environmental conditions.

Reproductive Habits

Scarab Hunter Wasps exhibit some unique reproductive behaviors. Remember, they are solitary creatures, so finding a mate can be a challenge. Male and female wasps will typically seek each other out using visual and chemical cues. After mating, the female goes on a search for scarab beetle grubs to lay her eggs on.

In summary, the life cycle of a Scarab Hunter Wasp is characterized by several distinct stages, from the egg to the adult. They are solitary creatures with fascinating reproductive habits, which involve the female laying her eggs on the larvae of scarab beetles as a food source for her offspring while they develop.

Habitat and Range

General Habitats

Scarab Hunter Wasps are known to inhabit areas with a variety of soil types. You can often find them in places with sandy banks, which serve as ideal nesting sites. These wasps are attracted to environments offering ample sunlight and minimal vegetation, as it allows them to efficiently locate their prey – Scarab beetle larvae. In these habitats, you’ll notice their nests are created in loose soil and can be easily recognized by their cylindrical shape and small entrance hole.

Geographical Distribution

Scarab Hunter Wasps have a widespread range, spanning across multiple continents. They are predominantly found in:

• USA: Particularly in California and Southern Okanagan Valley
• Canada: In British Columbia, specifically the Similkameen valleys and Summerland region
• Europe: Widespread presence in various countries
• Asia: Found in multiple regions

It’s crucial to note that their distribution may vary depending on the specific species of Scarab Hunter Wasp, weather patterns, and availability of prey.

Diet and Feeding Habits

Primary Diet

Scarab Hunter Wasps primarily feed on the grubs of beetles, especially those from the Scarab family. These wasps also consume nectar from flowers as an energy source. Some examples of flowers they may visit include elderberry and other flowering plants.

Feeding Habits

As a Scarab Hunter Wasp, your main hunting strategy is to search for grubs by digging in the soil. Once you find a grub, you paralyze it with your sting and then lay an egg on it. The hatched larva will eventually feed on the immobilized prey.

While hunting for grubs, you also play an essential role in pollinating the flowers you visit for nectar. By visiting different flowers, you inadvertently transfer pollen between them, helping the reproduction of plants. Here’s a summary of the feeding habits:

• Grubs as the main food source
• Nectar from flowers for energy
• Pollinating flowers during nectar feeding

Remember, as a Scarab Hunter Wasp, you have a unique and crucial role in maintaining the balance of your ecosystem and the reproduction of flowering plants.

Interactions with Other Species

Predator-Prey Relationships

Scarab Hunter Wasps are known to have a close relationship with various beetle species, especially the ones belonging to the Scarab family. These wasps are considered beneficial because they help manage populations of scarab beetles, which can be harmful to plants and crops. For instance, Scarab Hunter Wasps prey upon Japanese beetles, June beetles, lined June beetles, and ten-lined June beetles.

Their larvae primarily feed on the larvae of beetles. When the adult female wasps locate scarab beetle grubs, they paralyze the prey with their stingers and lay their eggs near or on the paralyzed beetle larvae. Once the wasp larva hatches, it consumes the beetle larva, effectively controlling the beetle population.

Interaction with Humans

Scarab Hunter Wasps are not considered aggressive towards humans; however, they might sting if they feel threatened. Their stings can be painful but are usually not life-threatening. It is essential to maintain a respectful distance from these wasps to avoid upsetting them.

Regarding interaction with other flying insects like bees, ants, and yellow jackets, Scarab Hunter Wasps are relatively non-territorial, meaning they will not often engage in conflict with these insects. Their primary focus is locating and hunting scarab beetle larvae.

To better understand the differences between Scarab Hunter Wasps and Yellowjackets, see the comparison table below:

In conclusion, Scarab Hunter Wasps can be a fascinating species to learn about, but it is good to remember that they play a vital role in controlling beetle populations and reducing negative impacts on plant and crop growth. Treat them with caution and a healthy level of respect to avoid any painful encounters.

Significance in Ecosystems and Agriculture

Role in Ecosystems

The Scarab Hunter Wasp plays a crucial role in maintaining the balance of ecosystems. They are natural predators of various beetle larvae, particularly those belonging to the scarab beetle family. By feeding on these larvae, they help to keep their populations in check, preventing them from causing significant damage to plant life.

Additionally, some species of Scarab Hunter Wasps are known to be pollinators, contributing to the reproduction of different plants. By visiting flowers in search of nectar, they inadvertently transfer pollen from one bloom to another, assisting in the pollination process.

Impact on Agriculture

As biological control agents, Scarab Hunter Wasps can be valuable allies for farmers. By preying on the larvae of agricultural pests like the Japanese beetle and May beetle, they aid in reducing the need for chemical pesticides. This natural biological control helps protect crops from damage and ensures a more sustainable approach to agricultural practices.

For example, Canadian records indicate that some Scarab Hunter Wasp species have been effective in controlling populations of destructive beetles in blueberry fields. This showcases the potential benefits of promoting these wasps as part of an integrated pest management strategy.

However, it is essential to consider that the overall impact of Scarab Hunter Wasps on agriculture may vary depending on factors such as species, location, and farming practices. Consequently, it is crucial to consult with experts and conduct further research before implementing them as part of a pest management plan.

Protection and Conservation Efforts

Scarab Hunter Wasps play a crucial role in controlling the population of pests, such as scarab beetles, in various ecosystems. To ensure their survival and maintain ecological balance, certain protection and conservation efforts need to be implemented. One way to do this is by preserving their natural habitats.

You can contribute to their conservation in your own backyard by creating a favorable environment for these wasps. Provide them with adequate nesting sites and plant native flowering plants to offer food sources for adult wasps. Additionally, avoid using chemical pesticides that may harm these beneficial insects.

At a larger scale, efforts such as the establishment of Habitat Conservation Plans can protect and enhance the habitats of various species, including the Scarab Hunter Wasp. Landowners may also receive support and incentives from the U.S. Fish and Wildlife Service to conserve and manage their lands and resources in a way that benefits at-risk species, like the Scarab Hunter Wasp.

Remember, even small efforts count when it comes to the protection and conservation of these fascinating insects. By taking part in those initiatives, you’re helping to maintain the balance of ecosystems in your area and ensuring the survival of these essential predators.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Scarab Hunter Wasps from Morocco

Subject:  Rabat Morocco, lovely wasps everywhere
Geographic location of the bug:  Rabat, Morocco
Date: 07/10/2018
Time: 03:31 PM EDT
Your letter to the bugman:  As July began, I saw more holes in the soil, and then these large and lovely creatures emerging from them. Now they are everywhere, buzzing about the bougonvillia, feasting on the marjoram, and dancing over the roses. They are about 1″ long, and though the pictures don’t show it well, they have yellow markings that are similar to the scolid wasp pictures supplied by others on the Mediterranean. It also has interesting segmented orange antennae.
How you want your letter signed:  Moroccan wasp fan

Dear Moroccan wasp fan,
Your images of this gorgeous Scarab Hunter Wasp or Flower Wasp in the family Scoliidae are truly beautiful as well.  We are having trouble identifying your exact species, but your individual’s similarity to this FlickR image of Scolia bidens from Mallorca causes us to speculate that you have captured images of a different Scolia species that also has distinctive orange antennae.

Thank you! They are really quite neat, especially because I had been wondering why there were so many holes. In Morocco, we have no screens so we share our home with any number of insects (there is a constant game with the ants, I hide the honey and they find it), but these ones are my favorite so far. I do feel a bit sad for the big bumbling beetles though, I assume the number of wasps is sadly inverse to the number of those ‘junebugs’ we saw.
Andrea

Hi again Andrea,
Insect populations do ebb and flow, so when prey is plentiful, the population of predators increases, and when prey is scarce, you will see fewer predators.  This is what keeps nature in balance.

Letter 2 – Scarab Hunter Wasp from Greece

Subject:  Wasp like insect
Geographic location of the bug:  Skopelos, Greece
Date: 09/12/2018
Time: 07:22 AM EDT
Your letter to the bugman:  On holiday this insect settled on me and was quite happy so folded its wings . Have asked some locals but they don’t know what it is .
How you want your letter signed:  Vivien

Dear Vivien,
This is a magnificent Scarab Hunter Wasp and thanks to images on pBase and on FlickR, we are confident it is Scolia hirta.

Letter 3 – Scarab Hunter Wasp from Kenya

Subject:  Not sure if it’s a wasp
Geographic location of the bug:  Mombasa, Kenya
Date: 12/30/2019
Time: 10:33 PM EDT
Your letter to the bugman:  I’ve been wanting to post here for a while. I’m Kenyan and our bugs are not available on the internet as much as in Western or Asian countries. Since I live in a coastal area, I see so many insects that I would love to have identified. My home area has a lot pf insects that usually find their way into the house. I found my sister, Sian, had killed this one and upon closer inspection wanted to know if it’s a spider wasp, a great black wasp or even a wasp at all (though it has the tell tale slim “waist”). The species I found online of the spider wasp all have antennae that are brightly colored but this one only had orange tips. I thought it was a great black wasp, because of the sudden increase in grasshopper populations, but most sites say they are large and have no colored antennae. The body is hairy (including the abdomen) and shiny and it has “gradient” wings which change between a dark blue to black depending on the angle. Hoping to post more bugs in future…
How you want your letter signed:  Danson, future regular poster…

Dear Danson,
This is definitely a wasp, but it is not a Spider Wasp.  In our opinion, it is a Flower Wasp or Scarab Hunter in the family Scoliidae, a group that preys upon the underground grubs of large Scarab Beetles, and Africa has numerous species of large Scarab Beetles, so there is a food supply for the Scarab Hunter Wasps.  We have not had any luck providing you with a species match.  According to BugGuide, a North American site, Scarab Hunter Wasps are “Robust, hairy, medium-sized to large.”  We look forward to your future submissions.

Thank you very much for the fast response… I’ll definitely post more…and you’re right, I think it’s a species of flower wasp…

Letter 4 – Female Scarab Hunter Wasp: Campsomeris tolteca

Subject: Bee on Steroids?
Location: Los Angeles, CA
June 27, 2014 3:10 pm
I saw this bee-hemouth on a flower outside my home here in the Los Angeles area.
It was around 1.5 inches long.
Looks like a bee, but isn’t a bee. Any ideas?
Signature: Just Me

Dear Just Me,
Several years ago we encountered this magnificent species of Scarab Hunter Wasp in Elyria Canyon Park in Northeast Los Angeles and we identified it as a female Campsomeris tolteca.  The species exhibits pronounced sexual dimorphism.  Both males and females visit flowers, but only the female hunts for Scarab Beetle Grubs to feed her brood.  BugGuide states:  “According to Nick Fensler: The females Campsomeris as well as other members of the subfamily Campsomerinae are predators on white grubs (Scarabaeidae), using these larvae as food for their young. Unlike sphecids, eumenines, and pompilids these wasps do not appear to have any type of prey transportation and dig to the ground-dwelling beetle larvae, sting it to paralyze it, and then lay an egg. They may dig around the grub to form a small cell. Since they use this nesting strategy they are often seen flying low to the ground (searching) in a figure eight pattern (but the flight pattern gets more erratic when they “smell” something). The adults use nectar as a food source and are common on flowers.”.  You may also compare your images to these images on BugGuide.

Wow very cool! I think it looks more like the plumipes. Thanks so much!

According to BugGuide, Campsomeris plumipes is not found west of Colorado.

Letter 5 – Female Scarab Hunter Wasp in Mount Washington

Subject:  Female Scarab Hunter Wasp
Location:  Mount Washington, Los Angeles, California
August 18, 2016 9:30 AM
Just as we were leaving the office today to gawk at the guerilla art Donald Trump sculpture at Wacko (see LA Times or LAist ), we had to make a slight delay to take some images of this gorgeous female Scarab Hunter Wasp, Campsomeris tolteca, nectaring on the flowering peppermint.  We first identified this species four years ago in Elyria Canyon Park.  Alas, the statue was in for the night, so we will have to return to Wacko during business hours.   Our identification of the female Scarab Hunter Wasp can be verified on BugGuide.

Letter 6 – Mating Scarab Hunter Wasps

Subject:  Hot wasp lovin’
Geographic location of the bug:  Rio Grande Nature Center, Albuquerque NM
Date: 05/18/2018
Time: 04:23 PM EDT
Your letter to the bugman:  Hello!  We were in the nature center and came upon dozens of these wasps.   The smaller ones, which we assumed are males, were flying maybe an inch or so above the ground and clearly searching for something.  The larger one, which we assumed was a female, suddenly emerged from underground and the smaller ones went crazy.
She kept trying to get away but couldn’t fly because her wings weren’t dry.  I believe I caught the actual act of mating in one of the photos.  Are these scarab hunters?   It’s the closest we could come in identifying them, but there wasn’t an exact match in the field guide.
How you want your letter signed:  Mike

Dear Mike,
Your images are awesome, and your written commentary is a marvelous observation.  We agree that these are Scarab Hunter Wasps in the family Scoliidae, but we are not certain of the species.  Our best guess is perhaps Crioscolia alcione (see female here on BugGuide and male here on BugGuide) or possibly Trielis octomaculata which is also pictured on BugGuide.  Members of this family exhibit sexual dimorphism, and males are smaller and often with markings different from those of the females.  Based on your observations, the males sensed the pheromones of the female that was about to emerge, and they waited for her to dig to the surface. 

Thank you!  That certainly looks like them.  There were dozens and dozens of the males searching everywhere.  They were quite friendly and just zipped around us with mild interest.

Male Wasps are physically incapable of stinging. 

Letter 7 – Scarab Hunter

Subject: What type of bee is this?
Location: Payson, AZ
September 23, 2013 9:56 pm
I found a beautiful orange and black bee on our property, in Arizona, that has black and blue iridescent wings. I took a photo of it that I am attaching.
Would Love to find out what this beautiful creature is! :O)
Thanks for your help!
Signature: Vicki

Hi Vicki,
This Scoliid Wasp is positively gorgeous.  According to BugGuide:  Wasps in the family Scoliidae are commonly called:  “Flower Wasps, Mammoth Wasps, Scarab Hawks,  [or] Scarab Hunters” and the “female digs down to the host grub, stings it, and lays an egg on the paralyzed grub” and those eggs develop into “Larvae [that] are parasitoids of ground-dwelling scarab grubs.”  Thanks to BugGuide, we have identified you Scarab Hunter as  Triscolia ardens.

Letter 8 – Scarab Hunter is Double Banded Scoliid

Subject: Megascolia maculata, mammoth wasp in Ontario?
August 15, 2014 5:18 pm
Hello,
Is there a subspecies of Megascolia maculata, not cicada killer, known to live in Eastern Ontario? Will send photos later if need be.
Signature: Noah

There are European Hornets.

Hi there,
I am trying to identify the species in the photo I’ve attached. It looks closest to photos of European/Eurasian mammoth wasps that I’ve seen.
Noah Cole

Dear Noah,
This Scarab Hunter Wasp is a Double Banded Scoliid, Scolia bicincta.  According to BugGuide:  “No doubt a parasitoid of beetle larvae, as are other members of this genus.”

Letter 9 – Scarab Hunter Wasp

What is this?
At first I thought I had some photos of the Cicada Killer wasp……… but now I’m not sure. In fact, I think I have something else…. coloration is not exactly right. However, here is a photo of my Bee/Wasp ?? nectaring on Milkweed. Question: What it? Haven’t seen this coloration before in our garden. We do seem to have lots of various types of bees and wasps lately. Location: Palm Beach Gardens, FL (southeast coast)
Pete

Hi Pete,
This looks to us like a Scarab Hunter Wasp, Campsomeris pilipes. The adults take nectar and the larvae feed on scarab beetle larvae. The female wasp provisions the underground nest with the beetle larvae.

Letter 10 – Scarab Hunter Wasp

Washed ashore ?
Wed, Mar 11, 2009 at 12:22 PM
I was walking down Vince beach, FL in the begining of March. I see many different inscets lying in the sand, but this particular one I have never seen before. Iwas woundering what kind of insect it is and what is the use of its large mandibles.
Chris Franklin
vince,fl

Hi Chris,
This is a Scarab Hunter Wasp in the genus Campsomeris. BugGuide has this remark: “According to Nick Fensler: The females Campsomeris as well as other members of the subfamily Campsomerinae are predators on white grubs (Scarabaeidae), using these larvae as food for their young. Unlike sphecids, eumenines, and pompilids these wasps do not appear to have any type of prey transportation and dig to the ground-dwelling beetle larvae, sting it to paralyze it, and then lay an egg. They may dig around the grub to form a small cell. Since they use this nesting strategy they are often seen flying low to the ground (searching) in a figure eight pattern (but the flight pattern gets more erratic when they “smell” something). The adults use nectar as a food source and are common on flowers.” We are confident your specimen is Campsomeris quadrimaculata, a robust wasp with a distinctly marked abdomen, which is well documented on BugGuide including many sightings from Florida.

Letter 11 – Scarab Hunter Wasp

Very large flying insect in compost pile
May 16, 2010
I first saw this bug when I was emptying yard trimmings onto the compost pile. Unfortunately I saw it too late that day and it got covered by the trimmings. It is very large 1 3/4 -2 inches with very bright orange bands on its abdomen? One thing I do remember was when I first saw it’s abdomen had bands of black hair/fur around the orange bands. With this siting It was crawling around on the ground about 10 feet from my compost pile. It now seems to be relatively smooth and if anything not as large as the previous time I saw it. Sorry for the photos all I had was my iphone… I have the good camera at the ready if I see it again.
Darin Davis
Austin, Central Texas, USA

Moth or Fly?
May 16, 2010
I recently posted a request for ID with some rather poor photos. Got another chance at photography with better results. Previous post… first saw this bug when I was emptying yard trimmings onto the compost pile. Unfortunately I saw it too late that day and it got covered by the trimmings. It is very large 1 3/4 -2 inches with very bright orange bands on its abdomen? One thing I do remember was when I first saw it’s abdomen had bands of black hair/fur around the orange bands. With this siting It was crawling around on the ground about 10 feet from my compost pile. It now seems to be relatively smooth and if anything not as large as the previous time I saw it. Sorry for the photos all I had was my iphone… I have the good camera at the ready if I see it ag ain.
Darin Davis
Austin, Central Texas, USA

Hi Darin,
We really want to thank you for going through the trouble to provide better images. Your first set would have made identification quite difficult if not impossible, though we knew by your written description that you probably had a Scarab Hunter Wasp in the genus Campsomeris, but we would not have ruled out a Digger Wasp in the genus Scolia. Your new photos will allow us to correctly identify it as the former, a Scarab Hunter Wasp in the genus Campsomeris, which takes nectar, according to BugGuide, and “Females provision nests with beetle larvae, esp. scarabs.” If your compost pile is like ours, there are probably numerous Scarab Beetle Grubs in it so that is is a rich hunting ground for the female Scarab Hunter Wasp. BugGuide also indicates: “Eric Eaton has pointed out in comments under various photos of Scoliids that there is considerable taxonomic confusion in this family, so that has to be a caveat in any photo identified as to genus here. According to Nick Fensler: The females Campsomeris as well as other members of the subfamily Campsomerinae are predators on white grubs (Scarabaeidae), using these larvae as food for their young. Unlike sphecids, eumenines, and pompilids these wasps do not appear to have any type of prey transportation and dig to the ground-dwelling beetle larvae, sting it to paralyze it, and then lay an egg. They may dig around the grub to form a small cell. Since they use this nesting strategy they are often seen flying low to the ground (searching) in a figure eight pattern (but the flight pattern gets more erratic when they “smell” something). The adults use nectar as a food source and are common on flowers.” Unless there are future taxonomic changes, we would identify your wasp as Campsomeris ephippium based on BugGuide’s images, and all reports on BugGuide’s data page were from Texas.

A friend of mine already identified it as Campsomeris ephippium see below.  It sure is a big wasp!
Thanks,
Darin Davis

May 16, 2010
Dear Darin,
Your bug is what I thought it was from Margaret’s description. Campsomeris ephippium, a wasp in the family Scoliidae. This is a really cool insect and not at all common. I’ve only photographed one and it was so heavy that it made the flowers bend down when it was feeding. What you’re seeing is a female looking to lay her eggs on scarab beetle larvae. That’s what the babies eat. Your compost probably has some of those huge grubs of the Ox beetle and that’s what she’s after.
You probably don’t have to worry about the wasp stinging you, but don’t go playing with it or anything 😉 This is a solitary wasp and they are not nearly as territorial as the social ones. Here are some other pics/comments on the web:
http://bugguide.net/node/view/328454/bgimage
Thanks for getting some pics and sending them. It’s fun to see some unusual insects like this.
Val

Thanks Daniel for the information.  Yeah there has been more than one occasion that I have inadvertently squashed a Scarab Grub in the compost screen.  This is a rather impressive/large wasp.  I would say for me that its rather large size makes me less primordially fearful than of a smaller more fluidly moving wasp.  I don’t know why I typed that other than I thought it to be an interesting observation.  From what I see it is not all that common and from the lack of any Central Texas (Austin)  chatter on the internet it seems to be moving further north.
Thanks Again,
Darin Davis

Letter 12 – Scarab Hunter Wasp

Not a cicada killer

Not a cicada killer
Location:  Cocoa (Brevard Co.), Florida, USA
October 13, 2010 8:54 pm
Hi Bugman!
Can you ID this big hymenopteran for me? He’s big, like almost cicada killer size, but seems more delicately built and slower moving. (We have cicada killers in the yard too–this is different, I’m pretty sure.) I’ve seen him several times on my stand of Monarda punctata and he sticks his little head waaaaaay into the flowers(nectaring? Pollening?). Seems almost clumsy while climbing on the plants (compared to the bees, wasps, flies, skippers) that are zipping around on there). He’s by far the biggest critter out there–except for the bigger butterflies–and among the slowest. He’s also quite hairy. A scoliid? Photos taken in late afternoon, Oct. 13, 2010, on Monarda punctata.
Thanks for your help and for this site–I can spend HOURS just looking and reading….fascinating stuff!
Signature:  LG

Hi LG,
You are correct about this being a Scoliid Wasp, and we believe it is Campsomeris plumipes, one of the Scarab Hunter Wasps.  You can compare your images to the numerous images posted on BugGuide.

Thanks very much for getting back to me—and so quickly! Doing more reading I’m now thinking that what I thought were standard scarab hunters in the yard are the females on their hunting mission and this guy is a male? Looks like the shape of the abdomen differs between sexes.

Letter 13 – Scarab Hunter Wasp

Big Bee?
Location: Orange County, California
July 28, 2011 2:12 pm
This large bee like bug hangs out around our home. He seems to be a predatory like bug. He flys right at us. Today we found it in the yard not looking all that wel. So we got close enought to take a photo. We usually leave bugs to do their thing in our yard, but I am curious if they sting or bite etc since I have two four year olds.
Any ideas?
Signature: Irish twins mommy

Dear Irish twins mommy,
Your insect is a Scarab Hunter Wasp, Campsomeris tolteca, which we identified on BugGuide which contains this fascinating information:  “According to Nick Fensler: The females Campsomeris as well as other members of the subfamily Campsomerinae are predators on white grubs (Scarabaeidae), using these larvae as food for their young. Unlike sphecids, eumenines, and pompilids these wasps do not appear to have any type of prey transportation and dig to the ground-dwelling beetle larvae, sting it to paralyze it, and then lay an egg. They may dig around the grub to form a small cell. Since they use this nesting strategy they are often seen flying low to the ground (searching) in a figure eight pattern (but the flight pattern gets more erratic when they “smell” something). The adults use nectar as a food source and are common on flowers.”  Solitary Wasps rarely sting people, however, if they are carelessly handled, a sting will most likely occur.

Letter 14 – Scarab Hunter Wasp

Subject: What’s this insect?
Location: Homosassa, Florida, United States
July 5, 2015 9:52 am
I live in the United States (Florida. I found this wasp floating in my swimming pool skimmer the other day. From what I’ve been able to determine, it is a male mammoth wasp. Is this a mammoth wasp? If so, are they now living in the United States. I’ve read that this species is from Europe. Thank you.
Signature: Melanie

Dear Melanie,
Your wasp is Scolia bicincta, a member of the family Scoliidae whose members are called Mammoth Wasps, Flower Wasps or Scarab Hunter Wasps.  We can assure you that your wasp is native.  This particular species is generally called a Scarab Hunter or Double Banded Scoliid, and the name Mammoth Wasp is generally reserved for the European species. 

Letter 15 – Scarab Hunter Wasp

Subject: Walking in Florida Pine Woods
Location: Near US 1 and Old Kings Road
August 8, 2016 12:58 pm
Hi,
I took a photo of this insect on a trail in Flagler County Florida yesterday, Aug 7, late in the day. The location was pine uplands at Hewitt Sawmill historic site. It was longer than an inch, had purplish long wings, made no sound at that time, black long body but not thin, and it had two yellow spots on each side of its abdomen. Its face looks like a giant ant. It was walking slowly across the shell-sand trail. The closest I found online is the Eastern Sawfly, but the markings don’t exactly match up. Could you pinpoint its identity?
thanks!
Signature: Tom Hanson, Palm Coast FL

Dear Tom,
This is a Scarab Hunter Wasp, a name that applies to the entire genus Campsomeris, and your individual is Campsomeris quadrimaculata with the species name of the binomial a reference to the four spots you observed.  You can verify our ID on BugGuide.  According to the genus page on BugGuide:  “According to Nick Fensler: The females Campsomeris as well as other members of the Campsomerinae use white grubs (Scarabaeidae) as food for their young. Unlike sphecids, eumenines, and pompilids these wasps do not appear to have any type of prey transportation and dig to the ground-dwelling beetle larvae, sting it to paralyze it, and then lay an egg. They may dig around the grub to form a small cell. Since they use this nesting strategy they are often seen flying low to the ground (searching) in a figure eight pattern (but the flight pattern gets more erratic when they ‘smell’ something). The adults use nectar as a food source and are common on flowers.”

Way cool!  Thank you.  I hope to see more of these out on my walks (and stay out of their way!), but if I’m with anyone I can now ID it thanks to whatsthatbug!  Best, Tom

Letter 16 – Scarab Hunter Wasp

Subject: Scarab Hunter Wasp?
Location: Orlando Florida
April 2, 2017 8:41 pm
Not sure of the ID on this one. It almost looked to be gathering pollen which I know wasps don’t do. Has three yellow dots on thorax. Photographed on a purslane flower.
Signature: Cledry

Dear Cledry,
We agree that this is a Scarab Hunter Wasp in the family Scoliidae.  We believe that based on the resemblance of BugGuide images of Campsomeris trifasciata to your individual, and by its range which includes Florida, that we have a proper identification.  We would not rule out that it might be Campsomeris plumipes, which is also represented on BugGuide.

Letter 17 – Scarab Hunter Wasp

Subject: Wasp or Bee
Location: Port Saint Lucie, Florida
April 30, 2017 6:57 pm
I found this insect resting with 4 others in the early morning on Salvia coccinea. I have tried to id it from books and internet, the closest seems to be Scarab Hunter, however I do not believe this is large enough at about 1-1.25 inches.
I photograph insects and id them to post on my Instagram @thedailybug with common and scientific names.
Thank you for your help. Your page is a great assistance.
Signature: Laurel Robertson

Dear Laurel,
This is indeed a Scarab Hunter Wasp, and we believe we have correctly identified it as Scolia nobilitata based on this and other BugGuide images.  According to BugGuide, it is a “Small scoliid with dark wings, abdomen dark with 4-6 light yellow/orange spots” and that is consistent with your observations.  The University of Florida has a nice paper on Scoliid Wasps of Florida and they provide this description:  “Variation: Body length is 10 to 15 mm. Segment 1 rarely with faint yellow spots, and those on segments 2 and 3 are sometimes very faint. Segments 4 through 7 may be dark mahogany to black.”  According to BugGuide data, sightings in Florida begin in May, so your individual was a bit early this year.

Letter 18 – Scarab Hunter Wasp

Subject:  Scolid wasp?
Geographic location of the bug:  New Jersey  Allaire State park
Date: 07/07/2018
Time: 02:27 PM EDT
Your letter to the bugman:  This is a scolid wasp I’m guessing?
How you want your letter signed:  Cindy

Dear Cindy,
This is indeed a Scarab Hunter Wasp in the family Scoliidae, and we believe, based on BugGuide images, that it is Campsomeris plumipes.  According to BugGuide:  “Scoliid wasps are parasitic upon larvae of soil-inhabiting scarab beetles.”

Letter 19 – Scarab Hunter Wasp

Subject:  flying all around my yard
Geographic location of the bug:  northern indiana
Date: 08/15/2018
Time: 10:51 AM EDT
Your letter to the bugman:  dont seem to be a threat, flying just above the grass, there is a lot of them
How you want your letter signed:  Joe

Dear Joe,
This is a solitary Scarab Hunter Wasp in the family Scoliidae, and they are not aggressive toward humans.  Your individual, Scolia dubia, is commonly called a Blue Winged Wasp.  According to BugGuide:  “Adults take nectar, may also feed on juices from beetle prey. Larvae are parasites of scarab beetles, mainly June beetles and also the introduced Japanese beetle.”  Since the grubs of both Japanese Beetles and June Beetles are injurious to cultivated plants and lawns, the presence of the Blue Winged Wasps is a good sign for your garden.  BugGuide also states:  “Males and females have a courtship dance, flying close to the ground in a figure-8 or S pattern. Females burrow into ground in search of grubs, especially those of Cotinis and Popillia japonica. She stings it and often burrows farther down, then constructs a cell and lays an egg on the host. Larva pupates and overwinters in a cocoon within the body of the host.”  You may have witnessed the courtship dance.

Letter 20 – Scarab Hunter Wasp

Subject:  Fly or wasp
Geographic location of the bug:  Allentown, pa
Date: 08/20/2018
Time: 06:42 PM EDT
Your letter to the bugman:  I saw three of these wasplike insects feeding today. They all had similar markings. What are they?
How you want your letter signed:  Tom in PA

Dear Tom in PA,
The Scarab Hunter Wasp, Scolia dubia, is just one of the numerous wasp species that feed on Goldenrod.  They hunt Scarab Beetle larvae as food for their brood.

Letter 21 – Scarab Hunter Wasp

Subject:  Large Black Desert Wasp other than Tarantula Hawk
Geographic location of the bug:  Lost Palms Oasis – Joshua Tree NP
Date: 09/04/2018
Time: 07:03 PM EDT
Your letter to the bugman:  While hiking in J-Tree this week (Early September), I came across a small swarm of large, black wasps around a patch of milkweed. I initially thought they were Tarantula Hawks, but upon closer inspection they were distinctly different from the T-Hawks I’ve seen around Southern California.
Description:
-Black Body approx. 1.5″ in length.
-Rust-Red Abdomen
-Black wings with a subtle blueish sheen.
-Found in a small swarm on Milkweed.
I’ve encountered many different bees and wasps on hikes, but never anything this large that wasn’t a Tarantula Hawk. I couldn’t find anything online that looked like them. Any ideas?
How you want your letter signed:  Ryan Dunn – @CogArtist

Dear Ryan,
We have identified your beautiful Scarab Hunter Wasp in the family Scoliidae as Triscolia ardens thanks to images on BugGuide where it states the range is:  “Texas west to California, and south into Mexico.”  According to BugEric:  “Their life cycle can be generalized as follows.  The female wasps fly low over the ground, somehow divining the presence of subterranean scarab beetle grubs.  Once she unearths the grub, she stings it into paralysis.  this allows her to lay a single egg on the grub.  After she accomplishes her mission, she re-buries the grub and flees the scene of the crime (some species have been observed moving the grub deeper into the soil and fashioning an earthen cell around it before depositing an egg and sealing the tunnel).  The beetle grub apparently never recovers from its coma.  The egg of the wasp hatches, and the larva that emerges will feed as an external parasite on its host for about a week or two before spinning a silken cocoon and pupating.  Most North American scoliids overwinter in the pupal stage.”

Letter 22 – Scarab Hunter Wasp from Ecuador

Subject: Ecuador Andes wasp
Location: Riobamba, Ecuador
November 4, 2012 12:33 pm
Here is a wasp we have been seeing while walking around in dry areas around Riobamba, Ecuador (elev. 2800 metres). They seem to live in tunnels in the sand, and like to sit on plants (sucking on the stems?). They are quite big (maybe 5 or 6 cm). They look like nasty wasps, but don’t seem to be aggressive. Any ideas?
Thanks,
Signature: Thanks, Ross

Hi Ross,
We are quite certain that this is a Scarab Hunter Wasp in the family Scolidae, and we believe it is in the genus Campsomeris.  A North American species, Campsomeris quadrimaculata, looks nearly identical.  BugGuide does not indicate if the range of this species extends to South America.

Letter 23 – Scarab Hunter Wasp: Triscolia ardens

Subject: Wasp identification
Location: Vail, az
June 30, 2015 10:02 pm
Hello,
On a hot and sunny tucson summer day I found this curiosity burrowed in my grass, apparently trying to keep cool. I know it’s not a tarantula hawk from the antenna, but it was making stinging-like motion with its abdomen on the stick I used to relocate away from me and my children. Wish I had a clearer picture of the mouth, but, what say you?
Thank you for your wonderful site!
Signature: Jennifer

Dear Jennifer,
Thanks for the compliment.  We believe we have correctly identified your Scoliid Wasp as Triscolia ardens based on images that are posted to BugGuide.  Alas, BugGuide does not provide any information on the species, and the genus information is also very limited on BugGuide except for “a single species in our area, 2 total”, however, the family page on BugGuide indicates common names “Flower Wasps, Mammoth Wasps, Scarab Hawks, Scarab Hunters” and provides this information:  “Larvae are parasitoids of ground-dwelling scarab grubs, esp. Phyllophaga; adults take nectar.  Life Cycle  Female digs down to the host grub, stings it, and lays an egg on the paralyzed grub.”  Perhaps your wasp is hunting for Scarab Beetle larvae in the lawn.  Scarab Hunters are not aggressive wasps, but because you were thoughtful enough to relocate it due to concerns for your children’s safety rather than to kill it, we are tagging your submission with the Bug Humanitarian Award. 

Letter 24 – Scarab Hunter Wasps

Subject:  hundreds swammed in yard
Geographic location of the bug:  kentucky
Date: 08/25/2018
Time: 01:09 PM EDT
Your letter to the bugman:  At first I thought these had something to do with the bag worms in a tree in my yard, but I have no idea what these are, maybe a bee? It’s a full blown infestation.
How you want your letter signed:  billie

Dear billie,
These are Wasps in the family Scoliidae, Scolia dubia, commonly called Scarab Hunter Wasps, Digger Wasps or Blue Winged Wasps, and they are not aggressive toward humans.  Female Scarab Hunter Wasps prey upon the grubs of Scarab Beetles, including Japanese Beetles, and the large number you have encountered indicates that last year, many Beetles did not mature as they provided food for the current generation.  We suspect they are interested in the evergreen shrub because they are feeding on sweet sap.

Letter 25 – What's Buzzing the Baccharis??? Scarab Hunter Wasps

Scarab Hunter Wasps on the Baccharis
Location:  Elyria Canyon Park, Mount Washington, Los Angeles, CA
October 14, 2012

In Los Angeles, we enjoyed our first (and early) rain of the season, and the weekend following is gloriously sunny and warm, but not too hot.  It seemed like a good day to visit the Baccharis in Elyria Canyon Park, camera in hand.  Soon after arriving, we photographed this large, nervous wasp that we thought might be a Scarab Hunter in the family Scoliidae, a hunch that eventually proved correct after returning home and checking BugGuide.

By the time we set the camera to macro feature and waited for the lengthy recording time, we managed to get two good photos and several less than ideal images.  A few minutes later, we noticed a more orange individual.  It should be noted that these are large wasps, at least 1 1/4 inches in length and easily twice as big as a Honey Bee.  As we moved closer to the more orange individual, it was buzzed by a more yellow individual that may or may not have been the individual we had just photographed.

The first thought that entered our mind was “could these be sexually dimorphic individuals of the same species?”  Well, that thought turned out to be accurate when we returned home and identified these Scarab Hunter Wasps as Campsomeris tolteca on BugGuide.  Alas, there is no species specific information on Campsomeris tolteca, but according to the data page, the species is reported from California to Texas along the border states.  The male images on BugGuide match our male and the female images on BugGuidematch our female.

Despite the lengthy record time, we managed to get two shots of both individuals together before the male flew off.  We then got several nice images of the female.

The best place we have discovered to read about the Scarab Hunter Wasps is on our contributor Eric Eaton’s blog, BugEric.  According to BugEric:  “Campsomeris wasps belong to the family Scoliidae, all of which are known parasitoids of scarab beetle grubs. A parasitoid is a parasite that invariably kills its host. Female scoliids, with their heavy, spiny legs, dig up a scarab grub, sting it into brief paralysis, and then lay a single egg on the beetle larva. Then the wasp leaves the scene. The grub eventually regains consciousness and control over its motor skills (such as they are), resuming its underground existence feeding on the roots of plants. Meanwhile, the wasp egg hatches and the wasp larva begins feeding as an external parasite of the beetle grub.”

Here is one final image of this impressive Scarab Hunter Wasp.