What do bed bug shed skins look like?

by nobugsonme on January 15, 2013 · 11 comments

in bed bug shed skins, bed bugs, photos

More helpful images from Lou Sorkin — in this case, images of bed bug shed skins. Bed bug shed skins are one of the visual signs we look for in order to confirm bed bugs: bed bugs, bed bug eggs, bed bug fecal stains and bed bug shed skins (which are also known as bed bug cast skins — usually among our European readers). So learning how to identify bed bug shed skins can be very useful.

Most people are surprised that shed skins look so much like bed bugs — kind of like the bed bug took off a full-body suit. It’s usual to see the legs and outline of other body parts.

3 shed skins of 5th instar bed bug nymphs

Lou Sorkin’s description of his photo:

“A dorsal, and 2 ventral views of the exuviae or shed skins of 5th instar bed bug nymphs. You can see the 3 dorsal scent gland areas on the middle of 3 dorsal abdominal sclerites in bug on left. You are looking into the bug: the thoracic sclerites split down the center and on head and the adult crawled out. The proboscis is evident as are 2 antennae of the bug on right. Contrast, brightness, gamma settings modified to enhance the sclerotized parts.”

And now, for their close-ups:

close-ups of 3 shed skins of 5th instar bed bug nymphs

Lou describes this image:

“Magnified view of the 3 exuviae (shed skins) of the 5th instar bed bug nymphs. Stylet fascicle and labium visible in shed skin on right (on its back, venter up). The fine, hairlike white strands in the sheds are the tracheae, very fine tubes (finer ones are tracheoles) through which air is transported within the body and are connected to the outside world via the spiracles (openings in body wall for air to enter and leave body– some can be seen where tracheae meets the body wall in shed on left, dorsum up). Can also look inside hollow leg sockets. Contrast, brightness, gamma settings modified to enhance the sclerotized parts.”

Golden bed bug skins!

These images of bed bug shed skins are actually, dare I say it, beautiful.

shed skin of 5th instar bed bug nymph

Lou describes this photo as follows:

“Side view of a shed skin (exuviae) of a freshly molted 5th instar bed bug nymph. Thoracic sclerites have a break in their centers and also in head area, so the sclerite breaks and the adult is able to crawl out. Membrane is pale, sclerotized body segments are darker brown. You can see antenna on front of head. Dorsal scent gland area on middle of 3 abdominal sclerites. Adult insect doesn’t retain the dorsal abdominal scent glands. Contrast, brightness, gamma settings modified to enhance the sclerotized parts.”

I love it when I can actually see the fine hairs on a bed bug image.

Thanks, Lou!

Note that we also have a helpful FAQ with photos from Franco Casini which compare bed bug shed skins with those of German cockroaches, dermestid beetle larvae, carpet beetles, and also an image which compares shed skins of bed bug nymphs of various stages: What do bed bug cast skins look like?

All images above used with permission of Lou Sorkin, under a Creative Commons Attribution/No-Derivatives license. You can view Lou’s photostream on Flickr.

Updated 7/2015

1 TAOT January 15, 2013 at 5:38 pm

Lou, what is the texture of the casts? How does the texture differ from carpet beetle casts? Are either cast hard to the touch? Can you show a grouping of skins without any fecal? Does that ever happen?

Final question (double points): what is carpet beetle fecal like? If you have “bites” and they turn out to be carpet beetles, will you ever see fecal and casts from carpet beetles in a similar way to bed bugs?

2 Sandy Honess January 16, 2013 at 9:03 am

Great images Lou. Thanks for taking these. Alot of folks mistake the cast skins for live bugs. Good to have these images.

3 Lou January 16, 2013 at 10:22 am

Shed skins of larval carpet beetles look very different from those of bed bug nymphs because the CB L is elongate and have legs way up front and does not resemble an adult beetle at all; the BB N resembles an adult BB in body shape. Cast skins are flimsy since they are only cuticle, no solid body. They will dry out some time after ecdysis (molting) and become more brittle and break up when touched or prodded. Bed bug legs easily break off of the shed skin.
See if this link works that shows adult and larval shed skin of a black carpet beetle. Stored food product pest in this picture. It’s also one of mine.
Yes, you can certainly locate adult beetles, larvae, shed skins, their droppings (dry, not released as wet like bed bugs). Shed skins (exuviae) may not be readily located around the bed, but could be under floors, carpeting, dresser drawers, etc. Bed bug harborages are often closer to where you are for longer periods of time (such as your bed, sofa, chair, futon) since its inhabitants like to be close to the next meal. You don’t matter to the carpet beetles since they don’t feed on you. They are basically around feeding on what’s left over: dead insects, dried animal carcasses, animal nests, hair, dander, furs, woolens, stored certain food products, etc. Adult beetles often attracted to light and can be found on window sills and other times are negatively phototropic and go to darkened areas, especially to lay eggs. The adults consume pollen from particular plants.

4 NotSoSnug January 16, 2013 at 5:45 pm

Thanks Lou, for the very interesting photos and descriptions.

I note on the first closeup dark material in the middle skin extending from the anus into the abdomen. Is the dark material just fecal matter stuck to the anus that extrudes during molt or a portion of the hindgut wall that detaches during molt?

I find it quite confusing that the trachae are fine white hairs and the background material also has fine white fibres.

5 Lou January 17, 2013 at 7:29 am

The dark material is fecal, not hindgut wall; it isn’t in all exuviae. Sorry about the background fibers. Tracheae are actually fine tubes and not fibers since air is carried within them to parts of body.

6 Winston O Buggy January 17, 2013 at 1:24 pm

Always a pleasure to see Lou Sorkin at work.

7 Jessi January 23, 2013 at 3:55 am

Thank you so much for all the great information!

There has been a smell in my room for quite some time and I couldn’t put my finger on it-it’s like a “funk” that I just can’t seem to get rid of. Also, I woke up last week with what I thought were misquetto (sp) bites (3 of them in a row) that were very swollen and very itchy. At first I thought I might have been bites from fleas because my dog sleeps on my bed with me…..but now I’m almost positive they’re from bedbugs.

Can you tell me the difference between bedbug and flea bites-just in case? I feel itchy sometimes and find myself scratching these little itches I have….can they get on your clothes and hang out in them?

Also, is it safe to sleep in the bed before changing the bedding and cleaning the room? Is there anything else I can do to get rid of the “funky” smell?

Thanks again for your help, I appreciate it 🙂

8 Lou January 23, 2013 at 10:08 am

Actually there is nothing to do to get rid of the smell because you don’t know the origin. You should place monitors to see if you can capture any crawling creatures. Examine places to see if you can find any evidence of the insect or artifact from them if are bed bugs, for instance.
Check out the the FAQ section of this site for assistance. If you find anything, you can take a picture and email it or go to the forum section and post a message and link your image from flickr.com or other photo sharing site. Instructions for all this also on the forum area.

9 Carlo@PestVlog January 23, 2013 at 11:42 am

Question Lou, when the body is fully engorged, does that blood fill the entire Bed Bugs body? And if so, where does all that current liquid go? Or does it simply fuse together?
Seeing just there casts really gives you an “inside look” on natures work. Astonishing that they live only in a modern world now. We filmed natures work when we filmed this Bed Bug flipping over – http://www.youtube.com/watch?v=yUb_6zqxWoM

10 Lou January 24, 2013 at 4:24 am

The shed skin is only the skin, the outer covering plus what internal structures are derived from the same cells in the embryo. Beginning and end of the digestive tract are of ectodermal origins. The internal organs are not not in the shed skin. The blood that is taken in during feeding is in the gut. Engorged bed bugs have their digestive tract full of blood and in different stages of digestion over time as its food is moved through to finally be voided when it is ejected out.
That’s a nice close up of the bed bug righting itself. You can see a movie of the same behavior I took some time ago plus some others regarding bed bug behavior. http://www.youtube.com/user/lougentpix

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