16 replies to this topic

[kellakk]

Does anyone know why only queen ants seem to have the set of 3 ocelli on their heads?  I know other hymenopterans have it too, but I don't know if the worker castes in other eusocial/partly eusocial hymenopterans have ocelli.

[Gregory2455]

It is like their sonar, or extra vision for mating flights.

[drtrmiller]

Males do, also.

 

I won't bother looking for references, but it is speculated, from what I've read, the 3 lenses in ants are used during flight for enhanced stability and locating a mate.

[Gregory2455]

What are these though on workers? Primitive or underdeveloped ocelli?

http://www.antweb.or...project=calants

http://www.antweb.or...project=calants

http://www.antweb.or...project=calants

http://www.antweb.or...project=calants

[kellakk]

Oh, I see.  The use of ocelli for flights makes sense, it could help them orient vertically.  Actually, that hypothesis could be easily tested in a laboratory setting if a mating flight can be triggered... Where would I find those reference?  That'd be a fun experiment with great potential.

 

I had never seen ocelli on any of the workers of species I looked at, that's interesting.  I wonder if the occurrence of ocelli on workers is an ancestral trait, or does it have some use in those species that have it?  

[drtrmiller]

They're very common in insects.

 

You should see if there are particular genera of ants where most or all documented workers possess them.  Then, think for a second about what the ants of these seemingly unrelated genera have in common.

 

The answer may surprise you.

[Gregory2455]

Good vision? I do not know...

 

Then, think for a second about what the ants of these seemingly unrelated genera have in common.

[kellakk]

All of the genera that Greg listed spend a lot of time in trees? That's the best that I can do...

[drtrmiller]

Look at Cataglyphis.  They definitely don't spend time in trees, but they are overly reliant on sight for navigation.  

 

What other genera can you find?

Edited by drtrmiller, February 23 2015 - 9:09 PM.

[Gregory2455]

Myrmecia seem to have them, I know they rely a lot on sight.

[kellakk]

Well, clearly it has to do with navigation of some sort.  I just read a couple of articles on the role of ocelli in Melophorus bagoti, and they seem to use the ocelli both as a celestial compass and as a part of path orientation.  However, I'm not convinced that those results would hold true for all ant species that have ocelli in the worker caste.

[James C. Trager]

Not ants, but speaking of ocelli, look at this bizarre wasp with a wayward ocellus - https://www.facebook...58265968&type=1

[dspdrew]

Not ants, but speaking of ocelli, look at this bizarre wasp with a wayward ocellus - https://www.facebook...58265968&type=1

 

Only someone with a Facebook account AND permission to view that will be able to. I have a Facebook account, but don't seem to have permission to view that.

[James C. Trager]

 

Here you go. Click to enlarge.

Edited by James C. Trager, February 24 2015 - 2:35 PM.

[dspdrew]

Maybe I'm not seeing it right, but that thing's head doesn't look very symmetric to me.

[Miles]

Maybe I'm not seeing it right, but that thing's head doesn't look very symmetric to me.

I think it is deformed.

[James C. Trager]

Like I said, a wayward ocellus.

Edited by James C. Trager, February 25 2015 - 8:08 AM.