Weird Weevil Wildness

[MikeBinOKlahoma]

Okay, so it isn't actually "wild", but I found it very peculiar. This is the same "mystery weevil" I posted earlier today--With the new policy, I'm gonna go ahead and post another shot.

This is a 100% crop of one of my weevil shots. What interested me is that this weevil is blowing bubbles. More precisely, he has a drop of fluid (water?) in his mouth, and he was manipulating it and it was going in and out. This struck me as odd behavior at the time, but I couldn't see the rather dim outline of the bubble (the fluid is pretty clear, but there is some gunk in it you can see cutting off abruptly at the curved forward edge of the bubble--I couldn't see it through the viewfinder, but I could tell something odd was going on). And I could tell he was holding his mouth open.

We've seen this behavior in several shots people have posted earlier from many different species of insect.
http://www.photomacrography1.net/forum ... .php?t=576

Above is an example. I seem to recall Danny posting a fly mouthing out something vivid (orange, maybe) but can't locate it now.

I'm wondering what this is. The most obvious answer is temperature regulation, but if anything, the weevil should have been chilly being taken from the subtropical outside of Miami Beach to several hours in an air-conditioned hotel room. Humidity regulation doesn't explain either, it must have seemed very dry to him.

I have a book about insect temperature regulation (I know, I'm sick) called "The Thermal Warriors" (quite a good and readable book, actually) and I can't find anything on this sort of behavior in paging through it. I may have to use this as an excuse to reread the thing!

It's Finals week or winter break here at our Universities, when things get back to normal, I am gonna try to call the entomology department at one of our schools and see if one of the all-knowing PhDs can give me an answer!

controlled situation
180mm macro with 2x teleconverter
tripod mount
100% crop of small portion of image
1/250th second @ f/22
ISO 160

[nzmacro]

I copied this and pasted it into Photoimpact....no I didn't save it , but I was interested as well Mike. Yep, thats a bubble alright. Amazing for a crop and very interesting behaviour shot. Exactly why they do this, I'm not too sure mate. I've been told about controlling temperature and also the threatened aspect of it. I'm still not convinced Mike. What ever it is, its interesting for sure.

All the best Mike, excellent seeing and a great crop IMO.

Danny.

[S. Alden]

This is interesting. I talked to the guys over in our entomology department about the bubble blowing and if memory hold up, they said the color of the bubble depended on what they just ate. It is a digestive thing they do. At least for flies, as that was the example I asked about (Danny's orange bubble vs. my clear bubble).

[nzmacro]

Yes that seems to make sense Sue. One of my shots is a yellow/brown colour and that looks like regurgitating. The others are crystal clear, so it must just be in the digestive juices as you say.

Certainly is interesting behaviour thats for sure.

Danny.

[MikeBinOKlahoma]

Digestion might make sense, especially if they do it instinctively whether they've eaten or not. When I took this shot, the little guy had been without any food for eight hours or so, so his digestive tract was surely pretty empty. Thus we have a clear bubble.

Danny, the comment about feeling threatened may be worth following up on. In North America we have several species of grasshopper that spit "tobacco juice" onto anything that they feel is a threat (including humans who pick them up). The grasshoppers have learned to incorporate toxins into this. I can't remember now whether they manufacture the toxins, or save them up from plants they eat. But the toxins are a mildly effective pesticide.

Maybe some species of insects that aren't as far along in evolving that type of defense spit up their digestive juices. Presumably the fluids that can break down food are going to be irritating, or at least unpleasant when smeared onto the eyes, antennae, or body parts of an aggressor.

I'm gonna think about this some more, and eventually will ask some questions of whatever experts I can find. Sue, if you get anymore input from your entomologists, please let us know!