Chalcid Wasp: All You Need to Know in a Nutshell

Chalcid wasps are tiny, yet fascinating creatures that play a significant role in ecosystems. These small, dark-colored parasitic wasps can often be observed with metallic blue or green hues and complex sculpturing on their bodies. Ranging in size from 1/50 to 1/16 inch, hundreds of species inhabit regions like the Pacific Northwest, where they mostly target the eggs and larval stages of moths, flies, grasshoppers, and beetles [1].

These beneficial insects contribute to natural pest control, making them a valuable asset in gardens and agricultural environments. Studies on the biology of parasitoid wasps reveal that the larvae feed on pests, while adult wasps consume nectar, pollen, and honeydew [2]. Depending on the species, Chalcid wasps can have various effects on trees, such as the chalcid wasp family Eurytomidae, which has only been found on Pinus eldarica (Afghan pine) and infests trees of all ages [3].

Chalcid Wasp: Basic Information

Size and Appearance

Chalcid wasps are tiny insects, usually measuring from 1/50 to 1/16 inch in size. They exhibit metallic blue or green coloration and display intricate sculpturing patterns on their body. These wasps have wings, which enable them to fly.

Order Hymenoptera and Superfamily Chalcidoidea

Chalcid wasps belong to the order Hymenoptera, and they are part of the superfamily Chalcidoidea. Hymenoptera includes other well-known insects like ants and bees. Within Chalcidoidea, there are many different species that share distinct features:

• Antenna: Chalcidoid wasps have a characteristic antenna with an extended, thread-like part.
• Wings: They possess two pairs of wings, one larger than the other.
• Size: Chalcidoid wasps are generally small in size, often barely visible to the naked eye.

Worldwide Distribution

Chalcid wasps can be found all over the world, with hundreds of species present in various regions. For example, the Pacific Northwest is home to numerous species that primarily attack the eggs and larvae of other insects, like moths, flies, grasshoppers, and beetles source.

Classification and Families

Family Chalcididae

Chalcid wasps belong to the order Hymenoptera, within the subphylum Hexapoda, phylum Arthropoda, and kingdom Animalia. Specifically, they belong to the family Chalcididae in the no taxon “Parasitica”—a group of parasitoid wasps¹. There are several families within Chalcididae, including Agaonidae and Mymaridae.

• Features:
  • Small size, usually less than 1/2 inch long
  • Parasitic or parasitoid lifestyle

Agaonidae and Fig Wasps

Agaonidae, also known as fig wasps, is a family within Chalcididae. They have a unique relationship with figs, as they play a vital role in the pollination of these plants².

• Characteristics:
  • Size: Approximately 1.5 millimeters in length
  • Symbiotic relationship with fig plants
  • Key role in ecosystem as pollinators

Mymaridae and Fairyflies

The Mymaridae family is another group within Chalcididae, commonly known as fairyflies. These tiny wasps are among the smallest insects in the world³.

• Features:

  • Size: As small as 0.2 millimeters in length
  • Often have delicate, fringed wings

• Examples:

  • Dicopomorpha echmepterygis
  • Kikiki huna

Comparison Table

Chalcid Wasp Life Cycle and Behavior

Parasitic Behavior

Chalcid wasps are known as parasitoid wasps due to their unique behavior of laying eggs inside or on the body of their host insects. Some common hosts include:

• Moths
• Nematodes
• Galls

Eggs, Larvae, and Pupae

Once the chalcid wasp lays an egg(s) on or within its host, the larvae start feeding on the host tissue. The larvae stage varies in length depending on the specific wasp species and the host type. After completing their development, the larvae become pupae, eventually emerging as adult wasps.

Adult Wasps

Adult chalcid wasps feed on nectar, pollen, and honeydew. They are typically small, ranging from the size of a pepper fleck to under 1/2″ long. Adult life spans differ among species but are generally short, lasting only a few weeks.

Features of adult chalcid wasps:

• Small size
• Nectar, pollen, and honeydew diet
• Short life span

Sounds they make

Chalcid wasps are small, and their sounds are often inaudible to the human ear. They may produce tiny buzzing sounds when flying, but these are typically drowned out by other environmental noises.

Impact on Agriculture and Gardens

Garden Pests

Chalcid wasps play a significant role in controlling garden pests. They are parasitoids to a variety of insects, such as aphids, leafhoppers, whiteflies, scale insects, and some beetles, flies, butterflies, and spiders. Examples of targeted pests include:

• Aphids
• Whiteflies
• Scale insects
• Leafhoppers

Helpful Predators

They are considered beneficial insects in agriculture as they help control garden pests. Gardeners and farmers often rely on these tiny wasps to naturally keep pest populations in check. Some specific examples of Chalcid wasp species that act as helpful predators include:

• Aphid Parasitoids: target aphids to protect plants
• Scale Insect Parasitoids: focus on controlling scale insects

Specific Plant Interactions

Chalcid wasps have different interactions with various plant species. Some wasps are drawn to specific plants, which can then be used to attract and maintain their populations in gardens and agricultural spaces. A few examples of plants that attract Chalcid wasps are:

• Alfalfa
• Yarrow

Chalcid wasps can benefit plants by controlling pests from the Hemiptera order, such as leafhoppers, which can damage stems and flowers. However, they may not be as effective against certain beetles, flies, butterflies, or spiders since they are selective in their targets.

Research and Literature on Chalcid Wasps

Major Studies and Discoveries

• Optimized DNA extraction and library preparation for minute arthropods: A study on the application to target enrichment in chalcid wasps used for biocontrol.
• Parasitoid assemblages associated with chalcid wasps: An in-depth analysis of food web structure in 18 species of chalcid wasps feeding on 10 grass species.

Taxonomic Changes and Synonyms

• Invasion from Anatolian Peninsula: Researchers found inferences on population history of a seed chalcid wasp and its potential invasion routes.

Resources for Further Reading

• Ecosystem services provided by aculeate wasps: A comprehensive review of how aculeate wasps, including chalcid wasps, contribute to regulatory, provisioning, supporting, and cultural ecosystem services.
• Wasp venom biochemical components: Learn more about the potential medicinal applications of various wasp venom components, including those found in chalcid wasps.

Comparison Table: Solitary vs. Social Wasps

Pros and Cons of Using Chalcid Wasps for Biocontrol

Pros:

• Natural pest control
• Low environmental impact
• Sustainable alternative to chemical pesticides

Cons:

• Risk of non-target effects
• Unpredictable results
• Might require additional pest control methods

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 – Chalcid Wasp: Brachymeria fonscolombei

Subject: Is this fly or bee dangerous to homeowner?
Location: South Eastern Massachusetts (Cape Cod)
August 12, 2012 5:28 pm
Hi guys!
This little fella is about 1/4 inch long and seems docile enough, but a client has several of them (she calls it an infestation – I counted six) in an enclosed entryway into her beachside, Cape Cod home. She thinks they are entering through the floorboards and that they burrow in the sand. I saw no evidence of burrowing. She is considering major renovations and other drastic measures. I would like to identify this insect, its food source and be able to tell her that tearing out the floor is not an answer and that they are not dangerous to humans. Can you help me out? Thanks again!
Signature: Tim Crowninshield

Dear Tim,
This is exactly the kind of letter we enjoy researching.  You have provided us with plenty of information as well as excellent photographs.  Additionally, you seem genuinely interested in learning about this creature to prevent its needless elimination.  We could tell immediately that your insect was a Chalcid Wasp, a group of parasitic hymenopterans, but we needed to identify it so that we could provide more specific information.  According to BugGuide‘s superfamily page on Chalcid Wasps:  “most parasitize eggs or immature stages of other insects or arachnids” and “Some are used to control insect pests (Lepidoptera, Diptera, Coleoptera, Hemiptera).”  We than found a matching photo on BugGuide identifying it as Brachymeria fonscolombei with the cryptic information:  “A whole group of these colorful chalcidids showed up in an office building. It turned out that a pigeon had died on the roof next to a ventilation duct. The larvae had crawled into the shaft to escape the summer heat and pupate.”  Intrigued we continued to research, but alas there was no helpful information on the species page, so we continued to search individual postings in the hope of learning more.  Another image on BugGuide provided this information:  “Emerged from a fly puparia.”  A third image on BugGuide contained this helpful bit of information:  “This species is a parasitoid of fly maggots. It can often be found hanging around road-kill.”  With all that information, we are now ready to pass on information for you to advise your client that this Chalcid is not harmful to her or her home.  It is actually a beneficial species that will help to control the fly population near her home.  If these Chalcids are actually emerging from the floor boards, it is possible that some animal died and rotted beneath the floor.  If she never noticed an odor, than it was most likely too small to be a problem during decomposition.  If Flies already found the rotting corpse, than the Chalcids have already done their job of consuming the maggots that would have eventually metamorphosed into adult flies.  The appearance of these Chalcids is most likely an indication that trying to remove the dead animal would not be necessary at this point as nature has already taken its course.  Again, we want to stress how much we enjoyed doing this particular bit of research.

Letter 2 – Parasitized Inchworm with Chalcid Wasp Pupae

Subject:  Stickbug?
Geographic location of the bug:  Silver Spring, MD
Date: 08/12/2018
Time: 12:14 PM EDT
Your letter to the bugman:  Found this in the back yard.  Looks like there maybe eggs on its back.  Is it going to mess up my garden?
How you want your letter signed:  Gene

Dear Gene,
Your “stickbug” is an Inchworm or Spanworm, the caterpillar of a moth in the family Geometridae, and they are excellent twig mimics.  What you have mistaken for eggs are actually the pupae of parasitoid Chalcid Wasps.  Here is a similarly parasitized Inchworm on BugGuide and here is an image of the Chalcid Wasp that emerged, also on BugGuide.

Letter 3 – Chalcicid Wasp

Subject:  Yellow winged tiny wasp like insects
Geographic location of the bug:  California
Date: 08/31/2018
Time: 01:34 PM EDT
Your letter to the bugman:  I found this on my car and i never seen this before i tried looking it up on internet but no pics or anything wondering if you can help please im curious
How you want your letter signed:  Adrian Barbosa

Dear Adrian,
This is a parasitoid Chalcidid Wasp, probably in the genus Conura, formerly Spilochalcis.  According to BugGuide:  “most attack Lepidoptera pupae; a few parasitize Coleoptera (Chrysomelidae, Curculionidae) and Diptera (Syrphidae); some are secondary parasites of Ichneumonidae and Braconidae.”

Letter 4 – Chalcid Wasp

ID yellow wasp
Hi,
I saw this tiny (between 10mm and 15mm) yellow wasp and would like your help to ID it. Right after this shot, I took a sequence of around 30 more shots of it laying eggs with a large ovipositor inside a pupa in a cocoon (below this leaf). The sequence was taken in the Botanical Garden of Rio de Janeiro, Brazil. Thanks a lot!!! Luis A. Flori

Hi Luis,
What a wonderful image of a Chalcid Wasp. Your description of the egg laying is very accurate with regards to this parasitic species. You photo greatly resembles a Golden Yellow Chalcid, Spilochalcis mariae, which has an extensive North American range. Your specimen might be the same, or a closely related species.

Hi, Thanks a lot, Daniel! Here you have the complete sequence of my (much bigger and detailed) shots of the Chalcid Wasp laying its eggs, just in case you want to look at it, with your ID acknowledgment at the end. It seems that to ID the pupa with these poorly lit images would be even more difficult… I searched the internet for another pictures of the wasp, but I wasn’t able to find any. Wonderful site you had built! Please keep it strong!! Thanks again!!
L.

Letter 5 – Chalcid Wasp

chalcid wasp in my house
May 24, 2010
Hi, just discovered that this is a chalcid wasp and that they are beneficials, but don’t know how or why they are in the house and would like to see if anyone knows what type of chalcid this is, bc I guess that term is pretty broad. Would these guys get in the house from a parasitized house fly?
Thanks!
Tiffany
Wilmington, NC

Hi Tiffany,
WE do not have the necessary skills to identify this Chalcid Wasp to the species level.  Most Chalcids parasitize insects in the orders Lepidoptera and Diptera, but some parasitize beetles.  According to BugGuide:  “All chalcidids are parasitic. Most attack pupae of Lepidoptera and Diptera, but some parasitize other Hymenoptera or beetles. Parasites of Lepidoptera usually attack young pupae, while those of Diptera attack mature larvae.”  We frequently receive letters regarding flies suddenly appearing in the home, and often a failure to remove garbage in a timely manner will cause maggots to proliferate.  An incident like that could give rise to the Chalcid sighting.

Letter 6 – Chalcid Wasp

Unidentified bug
Location: Virginia
August 10, 2011 8:27 am
https://lh6.googleusercontent.com/-CqODzDPwr6s/TjdQAR1dssI/AAAAAAAAHdk/76wYWF8GuVY/s640/DSC_4954.jpg
Saw this insect on a flower, haven’t been able to identify it.
Signature: Matt

Hi Matt,
We were uncertain if this was even a wasp or a fly, so we immediately contacted Eric Eaton for assistance.  Eric quickly wrote back.

Eric Eaton provided identification
Daniel:
It is a wasp, one of the chalcids.  Genus is probably Conura:
http://bugguide.net/node/view/83330
Great shot of what is a small wasp!
Eric

Chalcid Wasps generally parasitize caterpillars.  Eric Eaton has requested permission to post this image to his blog, and we would be greatly appreciative if you would allow Eric to disseminate this image and his information to his readership.  Eric has a long standing relationship with What’s That Bug? and we frequently consult him on difficult identifications.  A strong network of insect enthusiasts ensures that identifications will be easier for the web browsing public.

Letter 7 – Chalcid Wasp

odd parasitic wasp
Location: Beaverton, OR
August 15, 2011 8:09 pm
Found this little lady trying to bore holes in the side of our mason bee colony we made out of a 4×4. It’s ovipositor is extending from the first joint of the abdomen, I’ve never seen this before. Hopefully the photos will give you an idea of what this thing is. I’m dying to know!
Signature: Jason

Dear Jason,
Your photo is stunning, and perfectly composed to show the distinguishing features of this parasitic wasp.  We believe your wasp is a Chalcid Wasp, more specifically, Leucospis affinis, and about a year ago, we posted a photo of one.  We originally identified it on BugGuide.  According to BugGuide, it is “Parasitic on Megachilid bees” which is consistent with your observations.  We will be copying Eric Eaton because he is currently developing a blog post about Chalcid Wasps, and he may request permission to use your photograph.

Thank you! I’m very happy to have this gal identified. I hope she manages to lay a few successfully, that wood’s pretty tough. I’d be happy to allow the use of this photo in Mr. Eaton’s blog post, just let him know to mail me at this address so he can have direct confirmation from me. Thanks again for the compliment and a fantastic web site for us budding entomologists!

Letter 8 – Chalcid Wasp

Subject: TINY BEE?
Location: Fannie, Ark.
October 24, 2014 5:46 pm
This little bee (when I say little I mean smaller than the head of a pin) appeared in a photograph I took of another insect (Bluet). I literally could not see it until I had cropped the picture. It was on a Sicklepod Senna leaf. I didn’t think bees could get this tiny!
Signature: Bill

Dear Bill,
This is not a Bee, but rather a parasitic wasp in the family Chalcididae.  We believe we have identified it as Conura amoena, and according to BugGuide:  “hosts: hairstreak butterflies (Theclinae).”  Most parasitic wasps prey upon the immature stages of insects, and we are guessing that this Chalcid Wasp was searching for caterpillars, though of the genus BugGuide notes:  “most attack Lepidoptera pupae; a few parasitize Coleoptera (Chrysomelidae, Curculionidae) and Diptera (Syrphidae); some are secondary parasites of Ichneumonidae and Braconidae.”

Letter 9 – Chalcidid Wasp

Subject: what is this
Location: waco tx
October 12, 2015 6:45 pm
Don’t know what this bug is.. it’s in my house
Signature: what is it

There is not enough detail in your image for us to make a definite species identification, but the rear legs indicate that this is a Chalcidid, a parasitic wasp in the family Chalcididae.  It resembles this image from BugGuide of a member of the genus Conura.  Many members of the family pictured on BugGuide have the distinctive rear legs and this information is provided regarding diet:  “hosts: mostly Lepidoptera and Diptera, though a few attack Hymenoptera, Coleoptera or Neuroptera(1). Parasites of Lepidoptera usually attack young pupae, while those of Diptera attack mature larvae.”

Letter 10 – Chalcidid Wasps

Subject: Identify
Location: Memphis TN
July 24, 2017 8:57 pm
These were in my friends house and we don’t know what they are. Ranged in size from an ant to a large housefly.
Signature: Kim Hicks

Dear Kim,
These look like parasitoid Chalcid Wasps to us, but upon researching that possibility, we learned on BugGuide that:  “The terms ‘chalcid’ and ‘chalcid wasp’ typically refer to the whole superfamily Chalcidoidea, so it is best to use ‘chalcidid’ when specifically referring to this family.”  Following that advice, we believe this is a Chalcidid Wasp.  According to BugGuide:  “hosts: mostly Lepidoptera and Diptera, though a few attack Hymenoptera, Coleoptera or Neuroptera(1). Parasites of Lepidoptera usually attack young pupae, while those of Diptera attack mature larvae.“

Letter 11 – Chalcidoid Wasp

Baffling wasp
Location: Kickapoo State Park, Illinois
October 26, 2010 4:14 pm
I have a strange wasp I found at a local state park last week. Unlike most wasps, it did not have a tapering abdomen. I wondered if it was a queen of some sort, but I couldn’t find any matching images for a queen wasp. Any ideas?
Signature: Josh

Hi Josh,
We did not recognize this distinctive wasp, so first we tried Sawflies as a possibility.  We quickly abandoned that venture and explored the Parasitic Hymenopterans on BugGuide where we found Leucospis affinis pictured.  BugGuide indicates “One of the largest of the Chalcidoids in the U.S., and the only one exhibiting wing-folding as part of its mimetic morphology” and “Parasitic on Megachilid bees.”  The family Leucospidae page on BugGuide states:  “Usually black and yellow. They are stout insects, they fold wings longitudinally at rest and look a little like small yellowjackets. The ovipositor is long and curves forward and upward over the abdomen, ending over the posterior part of the thorax. Like the Chalcidids they have the hind femora greatly swollen and toothed on the ventral side.”  It is difficult to be certain because of the camera angle, but your photo does appear to show the ovipositor curved over the abdomen.

When I zoom in on the full-size shot, I can definitely see the ovipositor as shown on BugGuide. Thanks!
-Josh

Letter 12 – Golden Chalcid Wasp

Whats this (wasp)?
I’m in Jacksonville Florida and saw this little guy on on Cassia tree. Check out those hind legs! It also appears to have a (face?) on it’s rear end.. Can you tell me what it is please? I love your site, you guys and your contributors are amazing! Thanks,
George Fleischer

Hi George,
This is some species of Chalcid Wasp in the family Chalcididae. We found a match on BugGuide, but the species is not identified. We believe this might be in the genus Spilochalcis.

Letter 13 – Katydid Eggs Parasitized by Chalcid Wasp

Subject: Chalcid wasps from katydid eggs
Location: Kirksville, Missouri
April 10, 2014 1:02 pm
I discovered your site last fall in my search to identify some katydid eggs attached to a sweet gum ball. I kept the eggs on my desk in the hopes of seeing katydids hatching, but ended up having parasitized eggs–I had about a dozen chalcid wasps emerge from the eggs. Sadly, they didn’t survive.
I used this site and bugguide to figure out that they were chalcid wasps, but I’d like to narrow down the identification if possible.
Thanks!
Signature: AC Moore

Dear AC Moore,
We actually found your answer much faster than we anticipated.  We found this posting to BugGuide of Parasitized Katydid Eggs and a comment reads:  “The holes you are seeing are actually the emergence holes of wasps that parasitize the eggs of katydids. The wasps produce these circular holes to escape the confines of the egg in which they develop. When a katydid hatches it splits the side of the egg open. I know wasps in the genus Anastatus (Eupelmidae) and Baryconus (Scelionidae) attack katydid eggs having reared some myself.”  We then searched for images of wasps in the two mentioned genera, and this image of a Baryconus species on zsi.gov looks nothing like your wasp, however the Anastatus that is pictured on BugGuide looks very much like your wasp.  You are correct.  It is a Chalcid.

Letter 14 – Scelionidae (not Chalcid) Wasp emerges from Parasitized Eggs

Hey bug guru
I cant tell you how much I appreciate your dedication to one of my geeky passions. Your time and work does not go unappreciated. Please evaluate the attached photos. I hope they meet your guidelines for size. I found a few small eggs on a leaf in a ficus tree in the front yard. Lucky me, I just purchased a new microscope.

The egg pictures were taken at 100x and the hatch was taken at 50x. I live in Mesa AZ. I found the eggs on 4-21-07 and they started hatching on 4-27-07. The little bugger started to warm up and moving subjects at 50x are hard to capture. When he, sorry, or she was fully stretched out it looked like a miniature wasp. Im thinking some kind of boring wood wasp, but Im sure you will set me straight. The attached photos are composite images of over 60 taken on each final photo. The 5mp camera and the Image-Pro Express software are impressing the you know what out of me. The eggs are about half the size of a pin head. In some of the photos you can see small particles of dirt on the side of the eggs. Thanks to you and yours for all your work Thanks
Danny
Empire Fluids Lab

Hi Danny,
These are pretty awesome images, though hearing that they are composite has us a bit troubled. We hope the integrity of the actual even is faithful. We suspect that this is some species of Chalcid Wasp. Chalcid Wasps parasitize other insects, and according to the USDA: “All chalcidids are parasitic. Most attack pupae of Lepidoptera and Diptera, but some parasitize other Hymenoptera or beetles. Parasites of Lepidoptera usually attack young pupae, while those of Diptera attack mature larvae (Clausen 1940).” often Bugguide doesn’t have any documentation quite like this, and as the wasp and host are quite specific, we will see if Eric Eaton can assist us in identifying the eggs and wasps. We will also try to contact Bill Oehlke who operates an awesome Sphingidae page since these eggs look like they might be Lepidoptera eggs, and the Ficus Sphinx is a moth that feeds on Ficus. Thankfully, you not only provided us with awesome images, but with enough background information to continue sleuthing until we exhaust our means in the identification.

Daniel,
Thank you so much for you work on this. I want assure you that my integrity is of the highest. I have sent you picture’s in the past. This Leica will not let me take a clear single image and to appreciate the details of the egg I spent a bit of time stacking multiple images. Im dedicated to the appreciation of mother natures gifts. … Thanks again for all your time dedicated to informing the world on BUGS. It is nice seeing others around the world send pictures and how the site is growing. Thanks
Danny

Hi Danny,
Consider us chastised. There has been much publicity in the world of photo journalism due to photographers combining images digitally that, while they convey the truth of the experience, are still considered tampering. Your photos are quite gorgeous and the effort you have expended to assure detail in every portion of the image is obvious. We hope that both Bill Oehlke and Eric Eaton respond to our queries. Though we do not know the exact species here, we are still confident that your images are of a Chalcid Wasp. Thanks again for writing.

Hi Daniel,
I ran the photo by Lubo (Lubomir Masner) and he confirmed them to be male Trissolcus (Scelionidae:Telenominae: Trissolcus). Take care.
Hans

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 – Chalcid Wasp: Brachymeria fonscolombei

Subject: Is this fly or bee dangerous to homeowner?
Location: South Eastern Massachusetts (Cape Cod)
August 12, 2012 5:28 pm
Hi guys!
This little fella is about 1/4 inch long and seems docile enough, but a client has several of them (she calls it an infestation – I counted six) in an enclosed entryway into her beachside, Cape Cod home. She thinks they are entering through the floorboards and that they burrow in the sand. I saw no evidence of burrowing. She is considering major renovations and other drastic measures. I would like to identify this insect, its food source and be able to tell her that tearing out the floor is not an answer and that they are not dangerous to humans. Can you help me out? Thanks again!
Signature: Tim Crowninshield

Dear Tim,
This is exactly the kind of letter we enjoy researching.  You have provided us with plenty of information as well as excellent photographs.  Additionally, you seem genuinely interested in learning about this creature to prevent its needless elimination.  We could tell immediately that your insect was a Chalcid Wasp, a group of parasitic hymenopterans, but we needed to identify it so that we could provide more specific information.  According to BugGuide‘s superfamily page on Chalcid Wasps:  “most parasitize eggs or immature stages of other insects or arachnids” and “Some are used to control insect pests (Lepidoptera, Diptera, Coleoptera, Hemiptera).”  We than found a matching photo on BugGuide identifying it as Brachymeria fonscolombei with the cryptic information:  “A whole group of these colorful chalcidids showed up in an office building. It turned out that a pigeon had died on the roof next to a ventilation duct. The larvae had crawled into the shaft to escape the summer heat and pupate.”  Intrigued we continued to research, but alas there was no helpful information on the species page, so we continued to search individual postings in the hope of learning more.  Another image on BugGuide provided this information:  “Emerged from a fly puparia.”  A third image on BugGuide contained this helpful bit of information:  “This species is a parasitoid of fly maggots. It can often be found hanging around road-kill.”  With all that information, we are now ready to pass on information for you to advise your client that this Chalcid is not harmful to her or her home.  It is actually a beneficial species that will help to control the fly population near her home.  If these Chalcids are actually emerging from the floor boards, it is possible that some animal died and rotted beneath the floor.  If she never noticed an odor, than it was most likely too small to be a problem during decomposition.  If Flies already found the rotting corpse, than the Chalcids have already done their job of consuming the maggots that would have eventually metamorphosed into adult flies.  The appearance of these Chalcids is most likely an indication that trying to remove the dead animal would not be necessary at this point as nature has already taken its course.  Again, we want to stress how much we enjoyed doing this particular bit of research.

Letter 2 – Parasitized Inchworm with Chalcid Wasp Pupae

Subject:  Stickbug?
Geographic location of the bug:  Silver Spring, MD
Date: 08/12/2018
Time: 12:14 PM EDT
Your letter to the bugman:  Found this in the back yard.  Looks like there maybe eggs on its back.  Is it going to mess up my garden?
How you want your letter signed:  Gene

Dear Gene,
Your “stickbug” is an Inchworm or Spanworm, the caterpillar of a moth in the family Geometridae, and they are excellent twig mimics.  What you have mistaken for eggs are actually the pupae of parasitoid Chalcid Wasps.  Here is a similarly parasitized Inchworm on BugGuide and here is an image of the Chalcid Wasp that emerged, also on BugGuide.

Letter 3 – Chalcicid Wasp

Subject:  Yellow winged tiny wasp like insects
Geographic location of the bug:  California
Date: 08/31/2018
Time: 01:34 PM EDT
Your letter to the bugman:  I found this on my car and i never seen this before i tried looking it up on internet but no pics or anything wondering if you can help please im curious
How you want your letter signed:  Adrian Barbosa

Dear Adrian,
This is a parasitoid Chalcidid Wasp, probably in the genus Conura, formerly Spilochalcis.  According to BugGuide:  “most attack Lepidoptera pupae; a few parasitize Coleoptera (Chrysomelidae, Curculionidae) and Diptera (Syrphidae); some are secondary parasites of Ichneumonidae and Braconidae.”

Letter 4 – Chalcid Wasp

ID yellow wasp
Hi,
I saw this tiny (between 10mm and 15mm) yellow wasp and would like your help to ID it. Right after this shot, I took a sequence of around 30 more shots of it laying eggs with a large ovipositor inside a pupa in a cocoon (below this leaf). The sequence was taken in the Botanical Garden of Rio de Janeiro, Brazil. Thanks a lot!!! Luis A. Flori

Hi Luis,
What a wonderful image of a Chalcid Wasp. Your description of the egg laying is very accurate with regards to this parasitic species. You photo greatly resembles a Golden Yellow Chalcid, Spilochalcis mariae, which has an extensive North American range. Your specimen might be the same, or a closely related species.

Hi, Thanks a lot, Daniel! Here you have the complete sequence of my (much bigger and detailed) shots of the Chalcid Wasp laying its eggs, just in case you want to look at it, with your ID acknowledgment at the end. It seems that to ID the pupa with these poorly lit images would be even more difficult… I searched the internet for another pictures of the wasp, but I wasn’t able to find any. Wonderful site you had built! Please keep it strong!! Thanks again!!
L.

Letter 5 – Chalcid Wasp

chalcid wasp in my house
May 24, 2010
Hi, just discovered that this is a chalcid wasp and that they are beneficials, but don’t know how or why they are in the house and would like to see if anyone knows what type of chalcid this is, bc I guess that term is pretty broad. Would these guys get in the house from a parasitized house fly?
Thanks!
Tiffany
Wilmington, NC

Hi Tiffany,
WE do not have the necessary skills to identify this Chalcid Wasp to the species level.  Most Chalcids parasitize insects in the orders Lepidoptera and Diptera, but some parasitize beetles.  According to BugGuide:  “All chalcidids are parasitic. Most attack pupae of Lepidoptera and Diptera, but some parasitize other Hymenoptera or beetles. Parasites of Lepidoptera usually attack young pupae, while those of Diptera attack mature larvae.”  We frequently receive letters regarding flies suddenly appearing in the home, and often a failure to remove garbage in a timely manner will cause maggots to proliferate.  An incident like that could give rise to the Chalcid sighting.

Letter 6 – Chalcid Wasp

Unidentified bug
Location: Virginia
August 10, 2011 8:27 am
https://lh6.googleusercontent.com/-CqODzDPwr6s/TjdQAR1dssI/AAAAAAAAHdk/76wYWF8GuVY/s640/DSC_4954.jpg
Saw this insect on a flower, haven’t been able to identify it.
Signature: Matt

Hi Matt,
We were uncertain if this was even a wasp or a fly, so we immediately contacted Eric Eaton for assistance.  Eric quickly wrote back.

Eric Eaton provided identification
Daniel:
It is a wasp, one of the chalcids.  Genus is probably Conura:
http://bugguide.net/node/view/83330
Great shot of what is a small wasp!
Eric

Chalcid Wasps generally parasitize caterpillars.  Eric Eaton has requested permission to post this image to his blog, and we would be greatly appreciative if you would allow Eric to disseminate this image and his information to his readership.  Eric has a long standing relationship with What’s That Bug? and we frequently consult him on difficult identifications.  A strong network of insect enthusiasts ensures that identifications will be easier for the web browsing public.

Letter 7 – Chalcid Wasp

odd parasitic wasp
Location: Beaverton, OR
August 15, 2011 8:09 pm
Found this little lady trying to bore holes in the side of our mason bee colony we made out of a 4×4. It’s ovipositor is extending from the first joint of the abdomen, I’ve never seen this before. Hopefully the photos will give you an idea of what this thing is. I’m dying to know!
Signature: Jason

Dear Jason,
Your photo is stunning, and perfectly composed to show the distinguishing features of this parasitic wasp.  We believe your wasp is a Chalcid Wasp, more specifically, Leucospis affinis, and about a year ago, we posted a photo of one.  We originally identified it on BugGuide.  According to BugGuide, it is “Parasitic on Megachilid bees” which is consistent with your observations.  We will be copying Eric Eaton because he is currently developing a blog post about Chalcid Wasps, and he may request permission to use your photograph.

Thank you! I’m very happy to have this gal identified. I hope she manages to lay a few successfully, that wood’s pretty tough. I’d be happy to allow the use of this photo in Mr. Eaton’s blog post, just let him know to mail me at this address so he can have direct confirmation from me. Thanks again for the compliment and a fantastic web site for us budding entomologists!

Letter 8 – Chalcid Wasp

Subject: TINY BEE?
Location: Fannie, Ark.
October 24, 2014 5:46 pm
This little bee (when I say little I mean smaller than the head of a pin) appeared in a photograph I took of another insect (Bluet). I literally could not see it until I had cropped the picture. It was on a Sicklepod Senna leaf. I didn’t think bees could get this tiny!
Signature: Bill

Dear Bill,
This is not a Bee, but rather a parasitic wasp in the family Chalcididae.  We believe we have identified it as Conura amoena, and according to BugGuide:  “hosts: hairstreak butterflies (Theclinae).”  Most parasitic wasps prey upon the immature stages of insects, and we are guessing that this Chalcid Wasp was searching for caterpillars, though of the genus BugGuide notes:  “most attack Lepidoptera pupae; a few parasitize Coleoptera (Chrysomelidae, Curculionidae) and Diptera (Syrphidae); some are secondary parasites of Ichneumonidae and Braconidae.”

Letter 9 – Chalcidid Wasp

Subject: what is this
Location: waco tx
October 12, 2015 6:45 pm
Don’t know what this bug is.. it’s in my house
Signature: what is it

There is not enough detail in your image for us to make a definite species identification, but the rear legs indicate that this is a Chalcidid, a parasitic wasp in the family Chalcididae.  It resembles this image from BugGuide of a member of the genus Conura.  Many members of the family pictured on BugGuide have the distinctive rear legs and this information is provided regarding diet:  “hosts: mostly Lepidoptera and Diptera, though a few attack Hymenoptera, Coleoptera or Neuroptera(1). Parasites of Lepidoptera usually attack young pupae, while those of Diptera attack mature larvae.”

Letter 10 – Chalcidid Wasps

Subject: Identify
Location: Memphis TN
July 24, 2017 8:57 pm
These were in my friends house and we don’t know what they are. Ranged in size from an ant to a large housefly.
Signature: Kim Hicks

Dear Kim,
These look like parasitoid Chalcid Wasps to us, but upon researching that possibility, we learned on BugGuide that:  “The terms ‘chalcid’ and ‘chalcid wasp’ typically refer to the whole superfamily Chalcidoidea, so it is best to use ‘chalcidid’ when specifically referring to this family.”  Following that advice, we believe this is a Chalcidid Wasp.  According to BugGuide:  “hosts: mostly Lepidoptera and Diptera, though a few attack Hymenoptera, Coleoptera or Neuroptera(1). Parasites of Lepidoptera usually attack young pupae, while those of Diptera attack mature larvae.“

Letter 11 – Chalcidoid Wasp

Baffling wasp
Location: Kickapoo State Park, Illinois
October 26, 2010 4:14 pm
I have a strange wasp I found at a local state park last week. Unlike most wasps, it did not have a tapering abdomen. I wondered if it was a queen of some sort, but I couldn’t find any matching images for a queen wasp. Any ideas?
Signature: Josh

Hi Josh,
We did not recognize this distinctive wasp, so first we tried Sawflies as a possibility.  We quickly abandoned that venture and explored the Parasitic Hymenopterans on BugGuide where we found Leucospis affinis pictured.  BugGuide indicates “One of the largest of the Chalcidoids in the U.S., and the only one exhibiting wing-folding as part of its mimetic morphology” and “Parasitic on Megachilid bees.”  The family Leucospidae page on BugGuide states:  “Usually black and yellow. They are stout insects, they fold wings longitudinally at rest and look a little like small yellowjackets. The ovipositor is long and curves forward and upward over the abdomen, ending over the posterior part of the thorax. Like the Chalcidids they have the hind femora greatly swollen and toothed on the ventral side.”  It is difficult to be certain because of the camera angle, but your photo does appear to show the ovipositor curved over the abdomen.

When I zoom in on the full-size shot, I can definitely see the ovipositor as shown on BugGuide. Thanks!
-Josh

Letter 12 – Golden Chalcid Wasp

Whats this (wasp)?
I’m in Jacksonville Florida and saw this little guy on on Cassia tree. Check out those hind legs! It also appears to have a (face?) on it’s rear end.. Can you tell me what it is please? I love your site, you guys and your contributors are amazing! Thanks,
George Fleischer

Hi George,
This is some species of Chalcid Wasp in the family Chalcididae. We found a match on BugGuide, but the species is not identified. We believe this might be in the genus Spilochalcis.

Letter 13 – Katydid Eggs Parasitized by Chalcid Wasp

Subject: Chalcid wasps from katydid eggs
Location: Kirksville, Missouri
April 10, 2014 1:02 pm
I discovered your site last fall in my search to identify some katydid eggs attached to a sweet gum ball. I kept the eggs on my desk in the hopes of seeing katydids hatching, but ended up having parasitized eggs–I had about a dozen chalcid wasps emerge from the eggs. Sadly, they didn’t survive.
I used this site and bugguide to figure out that they were chalcid wasps, but I’d like to narrow down the identification if possible.
Thanks!
Signature: AC Moore

Dear AC Moore,
We actually found your answer much faster than we anticipated.  We found this posting to BugGuide of Parasitized Katydid Eggs and a comment reads:  “The holes you are seeing are actually the emergence holes of wasps that parasitize the eggs of katydids. The wasps produce these circular holes to escape the confines of the egg in which they develop. When a katydid hatches it splits the side of the egg open. I know wasps in the genus Anastatus (Eupelmidae) and Baryconus (Scelionidae) attack katydid eggs having reared some myself.”  We then searched for images of wasps in the two mentioned genera, and this image of a Baryconus species on zsi.gov looks nothing like your wasp, however the Anastatus that is pictured on BugGuide looks very much like your wasp.  You are correct.  It is a Chalcid.

Letter 14 – Scelionidae (not Chalcid) Wasp emerges from Parasitized Eggs

Hey bug guru
I cant tell you how much I appreciate your dedication to one of my geeky passions. Your time and work does not go unappreciated. Please evaluate the attached photos. I hope they meet your guidelines for size. I found a few small eggs on a leaf in a ficus tree in the front yard. Lucky me, I just purchased a new microscope.

The egg pictures were taken at 100x and the hatch was taken at 50x. I live in Mesa AZ. I found the eggs on 4-21-07 and they started hatching on 4-27-07. The little bugger started to warm up and moving subjects at 50x are hard to capture. When he, sorry, or she was fully stretched out it looked like a miniature wasp. Im thinking some kind of boring wood wasp, but Im sure you will set me straight. The attached photos are composite images of over 60 taken on each final photo. The 5mp camera and the Image-Pro Express software are impressing the you know what out of me. The eggs are about half the size of a pin head. In some of the photos you can see small particles of dirt on the side of the eggs. Thanks to you and yours for all your work Thanks
Danny
Empire Fluids Lab

Hi Danny,
These are pretty awesome images, though hearing that they are composite has us a bit troubled. We hope the integrity of the actual even is faithful. We suspect that this is some species of Chalcid Wasp. Chalcid Wasps parasitize other insects, and according to the USDA: “All chalcidids are parasitic. Most attack pupae of Lepidoptera and Diptera, but some parasitize other Hymenoptera or beetles. Parasites of Lepidoptera usually attack young pupae, while those of Diptera attack mature larvae (Clausen 1940).” often Bugguide doesn’t have any documentation quite like this, and as the wasp and host are quite specific, we will see if Eric Eaton can assist us in identifying the eggs and wasps. We will also try to contact Bill Oehlke who operates an awesome Sphingidae page since these eggs look like they might be Lepidoptera eggs, and the Ficus Sphinx is a moth that feeds on Ficus. Thankfully, you not only provided us with awesome images, but with enough background information to continue sleuthing until we exhaust our means in the identification.

Daniel,
Thank you so much for you work on this. I want assure you that my integrity is of the highest. I have sent you picture’s in the past. This Leica will not let me take a clear single image and to appreciate the details of the egg I spent a bit of time stacking multiple images. Im dedicated to the appreciation of mother natures gifts. … Thanks again for all your time dedicated to informing the world on BUGS. It is nice seeing others around the world send pictures and how the site is growing. Thanks
Danny

Hi Danny,
Consider us chastised. There has been much publicity in the world of photo journalism due to photographers combining images digitally that, while they convey the truth of the experience, are still considered tampering. Your photos are quite gorgeous and the effort you have expended to assure detail in every portion of the image is obvious. We hope that both Bill Oehlke and Eric Eaton respond to our queries. Though we do not know the exact species here, we are still confident that your images are of a Chalcid Wasp. Thanks again for writing.

Hi Daniel,
I ran the photo by Lubo (Lubomir Masner) and he confirmed them to be male Trissolcus (Scelionidae:Telenominae: Trissolcus). Take care.
Hans