Flying ant -- Pogonomyrmex

rjlittlefield · Post by **rjlittlefield** » Tue Jul 03, 2007 9:23 pm

I wrote up the story behind these pictures as a posting over in Community Member and Friends.

This beast looks a lot like the flying ant tentatively identified by Gordon C. Snelling as Solenopsis, over in this other behavioral post from a couple of weeks ago.

If I can provide more detailed pictures of any part to improve the ID, please let me know what's needed.

By the way, the long sharp spur that's apparently sticking down from the ant's left front tibia, really is a long sharp spur sticking down from the tibia. All the specimens that I collected have it.

--Rik

Technical:

Image #1 is stacked by HF, 30 frames at 0.010" focus step, using Canon 300D camera and Olympus 80 mm f/4 bellows macro lens at f/8, with its additional closeup lens. Incandescent illumination from two photofloods. The specimen is posed on a piece of balsa and is fresh but dead (retrieved that way from a water bottle co-opted as a collecting container, hence the various hairs and wings out of place).

Image #2 is from a Canon SD700 IS, auto-everything, taken live in the field.

Edit: corrected ant's name in title.

beetleman · Post by **beetleman** » Wed Jul 04, 2007 4:53 am

Excellent photos Rik. You can really see the humped back (muscles for the wings and food storage till the workers hatch) on the queen in the first pic..almost looks like a backpack

Very nice details and a great posing job on the specimen.

Edit: ooops, I guess I should not have assumed these were queens in the picture....

(Gordon has the trained eye)

MacroLuv · Post by **MacroLuv** » Wed Jul 04, 2007 4:55 am

Very nice and detailed, Rik.

I do not know much about ants. That is something for Gordon and Betty.

Balsa? It looks like a finger skin on #2.

Gordon C. Snelling · Post by **Gordon C. Snelling** » Wed Jul 04, 2007 5:52 am

Rik, these are Pogonomyrmex sexuals which were indeed out doing the nasty. I forget which species are in Washington though.There are several species of this genus which mate in these large groups called "Leks" You happened to be the perfect location for one of these little parties. Both ants in the closeups are males.

Planapo · Post by **Planapo** » Wed Jul 04, 2007 8:41 am

Rik - nice shots, especially the first one is impressively rich in detail.

Concerning the tibial spurs: In ants and many other insects these spurs together with the end of the tibia and the proximate part of the first tarsal segment form V-shaped grippers important for hygiene. When self-grooming insects can be watched pulling their antennae through the V-shaped gap, thus brushing and cleaning them.

Btw, from your second picture I can clearly see that we have another thing in common: Like Gordon and me, you too seem to be
a great ant hugger!

Cheers,
Betty

rjlittlefield · Post by **rjlittlefield** » Wed Jul 04, 2007 8:42 am

Thanks for the ID, Gordon! I'm curious about that strangly shaped spur on the front legs. I think I see it also in some Solenopsis images I found on the web. Is it a very common feature, and I just haven't noticed? What do they use it for?

Nikola, yes image #2 is thumb and forefinger of the left hand. Only image #1 is the balsa. Other interesting features in image #1 are a) the fuzzy light line on the abdoment -- which I'm pretty sure is reflection of a fluorescent ceiling fixture in the room where I shot the stack, b) the row of hooks along the front edge of the left rear wing, which would normally hold it aligned with the front wing, and c) it's obvious that this is a stacked photo from the way the balsa suddenly shifts from perfectly focused to completely blurred, no detail at all.

--Rik

Planapo · Post by **Planapo** » Wed Jul 04, 2007 8:47 am

Seems our entries crossed in cyberspace, Rik?!

rjlittlefield · Post by **rjlittlefield** » Wed Jul 04, 2007 8:53 am

Betty, yes, our posts crossed on the net. What puzzles me about the tibial spurs is only the shape. In poking through other ant pictures, I find a few that look like these, but in most the foreleg spur is thickened only a little compared to the other two legs. In the ants of this post, the middle and rear spurs look "normal", while the front spurs are broadened out into this shape that looks more like a leaf.

--Rik

Gordon C. Snelling · Post by **Gordon C. Snelling** » Wed Jul 04, 2007 9:05 am

I am not entirely sure what the spur is for but I suspect it may be used in grooming. Pectinate (comb like) spurs are not uncommon in ants.and is a feature often used when making identifications

Mike B in OKlahoma · Post by **Mike B in OKlahoma** » Wed Jul 04, 2007 9:26 am

Way to go, Rik! I wish these were mine!

Mike B in OKlahoma · Post by **Mike B in OKlahoma** » Wed Jul 04, 2007 9:33 am

The cue (or at least a cue) for male reproductive ants vs. females is the size of the thorax (second part of the insect), and the size of the gaster (aka abdomen--third, tail part of the insect).

Male reproductives (drones) have to compete with dozens of other eager males to mate with a queen. Mating usually takes place in flight, so drones have hyperdeveloped wing muscles to give them an advantage in the jousting for position. You can see that on these, especially in the first photo.

Females don't have quite the exaggerated wing muscles, and usually have larger gasters for more massive ovaries.

Planapo · Post by **Planapo** » Wed Jul 04, 2007 9:39 am

Rik - the spurs vary in size and shape quite a lot.

Just two ad hoc thoughts, as functional approaches:

Some species, e. g. the soil dwelling ones might be more affected by dust and dirt and therefore need more effective cleaning devices.

Males rely on their antennae for finding the female by chemoperception and thus clean antennae are essential.

Cheers,
Betty

MacroLuv · Post by **MacroLuv** » Wed Jul 04, 2007 11:06 am

Planapo wrote:... Males rely on their antennae for finding the female...

That is why I'm keeping my cellular phone clean!

Planapo · Post by **Planapo** » Wed Jul 04, 2007 11:48 am

Nikola -

(And btw, that´s not the first time you make me smile.)

Best wishes,
Betty

rjlittlefield · Post by **rjlittlefield** » Wed Jul 04, 2007 11:39 pm

Gordon C. Snelling wrote:... these are Pogonomyrmex ...

Gordon, thanks for the ID. I corrected the title of this topic.

I also posted out some higher magnification pictures of the pectinate spur.

Thanks for prompting me to take a closer look at that!

I'm sure I must have read about those things at some point, but it had completely slipped my mind.

--Rik