The sharpest end of a paper wasp

[rjlittlefield]

As far as I can tell, the anatomy of a wasp stinger basically consists of a conical hollow sheath having a broad C-shaped cross section, inside which there are two lancets, side by side, each with barbs on the outer surface and a grooved inner surface.

Earlier, I posted an overview shot of the end of abdomen with stinger exserted.

In this picture we see a closeup view of the tips of both lancets, the surrounding sheath -- which ends about 1/2 way down what's visible here -- and a bit of fluid captured in the grooves at the end of the lancets.

I read that the mechanism operates by pushing the lancets forward alternately, with the moving one cutting and penetrating while the fixed one holds the whole stinger in position aided by the passive action of the barbs. When both lancets are sufficiently deep, a shot of venom is delivered down the groove between the lancets, after which the wasp pulls out the whole assembly by simply ripping the barbs out of the victim's flesh. (I suppose I should say "the aggressor's flesh". The sting is delivered only defensively, of course. )

I have not read how fast all this happens, but judging from the size of the lancets, they really wouldn't have to vibrate very fast. Say 0.1 mm per stroke, 200 strokes per second, would take 'em skin deep in 1/10 of a second! Now that would be an interesting exercise to photograph...

--Rik

Technical: Canon 300D, 20X NA 0.40 microscope objective on 150mm extension, 8 frames stacked at about 0.0002". The subject is Polistes dominulus, a different specimen from the earlier overview.

[Adrian]

very cool, great detailed explination, thanks.

the first thing i notaced upon looking at it was those barbs, and i was thinking ouch.

[beetleman]

Incredible work Rik. Some really great detail showing in the stack. It just makes me want to stay away from them even more

[Ken Ramos]

Rik wrote:

The sting is delivered only defensively, of course. )

Doesn't take much to put them on the defense either!

[rjlittlefield]

Doesn't take much to put them on the defense either!

So I hear. But there seems to be quite a difference from one species to another. These particular beasts (the immigrant Polistes dominulus) are noted for being relatively non-violent, much more inclined to just threaten than to actually attack. It's been suggested that a) this feature is enabled by more obvious warning coloration than most paper wasps, and b) it may be partially responsible for the greater success of P. dominulus, over the native P. fuscatus. [ref]

I don't have a lot of data from personal experience, and I'm happy to keep it that way. The ones in my garden shed never did attack, despite having their nest only about a foot over the door. On the other hand, when it was time to remove the nest, I went equipped with gloves, goggles, hood, and a powerful vacuum cleaner. The process was successful and painless for me, less so for the wasps.

--Rik

[Ken Ramos]

Rik wrote:

I went equipped with gloves, goggles, hood, and a powerful vacuum cleaner

I don't know about that vacum cleaner Maybe a General Electric J-79 with the intake at the door might would do better. Don't cha' suppose? Probably would suck up some annoying neighbors kids too while you were at it.

[rjlittlefield]

The effect of the vacuum cleaner was pretty interesting. Any wasp that took off got sucked in, but apparently they're adapted for dealing with high winds because most of 'em just hunkered down and held onto the nest. Eventually I had to go in with a stick and pry 'em loose one at a time.

By the way, if you ever use this vacuum cleaner trick, be sure to carefully think through the whole process before starting to work. The first time I did this (several years ago...), I ended up with a vacuum cleaner full of live yellowjackets. The challenge, of course, then became how to kill the yellowjackets without ruining the vacuum cleaner. I forget what the solution turned out to be, but I remember it was a lot of trouble. This time, I sewed up a long skinny "sock" of mesh fabric, stuck it between two tubes of the vacuum cleaner, and had myself a nice little disposable filter. Worked great.

I'll have to think about the J-79 approach. That bit about the neighbors kids is a little scary. I like the ones that are there now, and if they disappeared, who knows what might move in!

--Rik

[Ken Ramos]

I was just thinking. If you put the vacum on blow after having sucked up the wasps or yellow jackets and ran it in someones window that you didn't like, well...

The F-4 Phantom is proof that if you put J-79's on a "rock," it will fly! Still a great fighter though, loved working on their weapons system.

[Mike B in OKlahoma]

By the way, if you ever use this vacuum cleaner trick, be sure to carefully think through the whole process before starting to work. The first time I did this (several years ago...), I ended up with a vacuum cleaner full of live yellowjackets. The challenge, of course, then became how to kill the yellowjackets without ruining the vacuum cleaner. I forget what the solution turned out to be, but I remember it was a lot of trouble.

Rik, as it happens, someone forwarded me this link just a couple of days ago....The perpetrator works in a lab--Wasn't you, by chance, was it?

http://www.darwinawards.com/personal/pe ... 07-04.html

Incidentally, the shot of the wasp stinger is amazing....

[Mike B in OKlahoma]

These particular beasts (the immigrant Polistes dominulus) are noted for being relatively non-violent, much more inclined to just threaten than to actually attack. It's been suggested.....it may be partially responsible for the greater success of P. dominulus, over the native P. fuscatus. [ref]

I've only killed one wasp in my life. While I was in the Army about 1987, I was about to move out of a Bachelor Officer Quarters into a more congenial setting off-post, when I noticed a "dirt dauber" wasp starting a nest just a few feet above my door. I was going to be gone in about two days, so I decided to just let it be.

A couple of days later, as I was carrying a load out to my car, the wasp, without warning that I could see, swooped down from above and stung me on the back of my neck! That might not have been so bad, except that I was carrying a color television set that was at the limit of my carrying capacity anyway! I managed not to drop the television set, carried it off to a safe distance, watchfully ran back into my quarters, and came out with a can of hair spray. I managed to spray the wasp as it swooped by, and the hair spray gummed its wings together. Nowadays, I'd be thrilled at the opportunity for major high-magnification macro opportunities on this specimen, but back in those days, I was more uncouth. I just practiced my Mexican Hat Dance on top of the wasp!

[Ken Ramos]

I wonder just how many of us would have done the same thing? Come on people...fess up!

I remember something that was very cruel but the outcome was funny despite the act of cruelty. These people hated cats and had one that began to hang around their home. In desperation to get rid of the cat, after several humane attempts, they set fire to it with lighter fluid. The cat proceeded in its agony to run under the house. Thus setting fire to it and burning it to the ground. Justice will prevail!

[rjlittlefield]

Rik, as it happens, someone forwarded me this link just a couple of days ago....The perpetrator works in a lab--Wasn't you, by chance, was it?

http://www.darwinawards.com/personal/pe ... 07-04.html

(Gasping, wheezing, choking with laughter. Holding sides in pain! Guffaw! Snort!! Wiping tears from eyes...)

No, not me. But so spectacular an image, I almost wish it were!

--Rik

[Walter Piorkowski]

Excellent work Rik. I tried to do such an image of a honey bee stringer I removed from my own flesh, throbbing poison delivering organ still attached. This was before my introduction to this form and I didn't get anything like you acieved here. And thanks Mike, I got a good chuckel out of that one.

Waly

[Planapo]

This one is at least as great as the overview shot! Master Rik has mastered the task again!

Hope I will be able to produce something alike eventually.

(Dunno why I didn´t add my bravos for this one in the first place, perhaps being busy with laughter about Mike´s story and got distracted.)

--Betty

[DaveW]

If a wasp sting is barbed but it can extract it from your flesh without ripping it's sting from it's body why is a bee supposed to kill itself when it stings because it's sting I understand is ripped from it's body and remains in your flesh with the venom sack still pumping. Does a bee have far more pronounced barbs on it's sting?

DaveW