Cuckoo's at Sunrise

[A-PeeR]

Sunrise on Buffalo Bayou mid November 2018, a group of male Coelioxys still asleep awaiting the morning sun for energy. One of my favorite bees to photograph, since Hurricane Harvey I am finding large groups of these bees. Pre storm, I was lucky to stumble across one or two on a hike. Looking forward to finding many more this spring



Photo specs:
Nikon D850
Sigma 150 Macro
45 Image field stack on tripod rig
RAW processing in DXO
Stacked in Zerene
Touch-up in PS

[ChrisR]

That's a nice scene. Are their eyes always like that?

[Olympusman]

Nice find and nice photo.

Mike

[A-PeeR]

That's a nice scene. Are their eyes always like that?

Thanks Chris,

Yes, I believe their eyes are always like that. Here is an image of a solitary Cuckoo I photographed a while back. It will give you a closer look at the peeper ;-)



Best regards - William

[A-PeeR]

Nice find and nice photo.

Mike

Thank you Mike...

[rjlittlefield]

This is a beautiful image!

Nikon D850
Sigma 150 Macro
45 Image field stack on tripod rig

Was this shot with the D850's built-in focus stacking using the motor in the lens, or with some sort of rail device?

Are their eyes always like that?

Are you're referring to the pattern of dark dots? Those look to me like a distorted version of the hexagonal pattern that we often see in butterfly eyes. From reading various articles, my understanding is that the anatomy of these eyes allows the dark-colored photoreceptors of each ommatidium to see straight out through their own ommatidium's lens, while also seeing obliquely out through the lenses of neighboring ommatidia, sometimes in multiple rings. Looking in from the outside, as we do, this arrangement produces as a dark pseudopupil where the ommatidia face us directly, with progressively less dark pseudopupils where the ommatidia face slightly away from us but at the correct angle for those photoreceptors to see us also. Presumably the insect's retina is wired to take advantage of this sort of multipath input, but I don't know if the details of that have been worked out.

Note: the above explanation is not correct. See corrected version, BELOW.

--Rik


Edit: to flag incorrect explanation.

[ChrisR]

ChrisR wrote:
Are their eyes always like that?

Are you're referring to the pattern of dark dots?

The yellowness really. I imagne it's basically hairs/setae but a lot of insects have those without making the eye look light.

[rjlittlefield]

The yellowness really. I imagne it's basically hairs/setae but a lot of insects have those without making the eye look light.

There definitely are yellow hairs, but I think the yellow surrounding the black spots is mostly reflection from internal structures. See for example https://www.flickr.com/photos/-can-/302 ... 6/sizes/o/ .

--Rik

[Thagomizer]

Are you're referring to the pattern of dark dots? Those look to me like a distorted version of the hexagonal pattern that we often see in butterfly eyes. From reading various articles, my understanding is that the anatomy of these eyes allows the dark-colored photoreceptors of each ommatidium to see straight out through their own ommatidium's lens, while also seeing obliquely out through the lenses of neighboring ommatidia, sometimes in multiple rings. Looking in from the outside, as we do, this arrangement produces as a dark pseudopupil where the ommatidia face us directly, with progressively less dark pseudopupils where the ommatidia face slightly away from us but at the correct angle for those photoreceptors to see us also. Presumably the insect's retina is wired to take advantage of this sort of multipath input, but I don't know if the details of that have been worked out.

--Rik

I've often wondered about that patterning, thank you. I had suspected it was an optical or depth effect that would shift and change with camera angle, rather than the result of any surface pigmantation. It's like a multiple version of the dark spots that show up in mantis eyes and follow you around?

[rjlittlefield]

It's like a multiple version of the dark spots that show up in mantis eyes and follow you around?

Yes, I believe that's exactly correct.

I'm guessing a little bit, because I've never played with one of these bees.

But at least in still images, the appearance looks just like what I'm familiar with in butterflies with light-colored eyes, such as the sulphurs and Painted Lady (example images HERE and HERE), and in those critters the multiple dark spots definitely move around with the observer.

--Rik

[A-PeeR]

This is a beautiful image!

Nikon D850
Sigma 150 Macro
45 Image field stack on tripod rig

Was this shot with the D850's built-in focus stacking using the motor in the lens, or with some sort of rail device?

Thanks Rik,

Capture was done with the in camera stacking utility/lens motor. It takes some practice to get a feel for the "step" size. I was conservative with this image. I probably could have compiled the same image with 20-to-25 images. One nice thing about the D850 is the "Silent Live View Photography" essentially an electronic shutter - no physical shutter (or mirror) movement during the stack acquisition. This all but eliminates any camera induced vibrations. Just keep your fingers crossed that the insects stay still and a slight breeze doesn't pick up...

Best regards - William

[MarkSturtevant]

Interesting points about the pseudopupils.
It can also be pointed out that cuckoo bees are so named b/c they are 'kleptoparasites', meaning they lay their eggs in the nests of other bees (like cuckoo birds). There are many species, and there are bees in various families with this behavior. Including some species of bumblebees (I was surprised to learn that recently).

[Troels]

Very nice pictures and interesting comments.

[rjlittlefield]

I've done some more reading about the pseudopupils. I think the story is firming up, and it's different from the way I had previously understood it.

At https://rcannon992.com/2019/01/02/the-e ... udopupils/ , Ray Cannon writes that

... essentially, if I have understood it correctly, the principal pseudopupil appears as dark spot because of the black – usually jet-black – pigments clustered closely around the cones. In the words of Professor D. G. Stavenga, of the University of Groningen, NL (pers. comm.), who authored an 80-page publication on this subject, ‘the pigments in the pigment cells surrounding the photoreceptor set of each ommatidium function as shields for stray light … they are usually blackish, absorbing throughout the whole wavelength range.’ So, in the principal pseudopupil, one is in effect looking right down a small group of ommatidia – down their vertical axis – and there is little or no light scattered back by the black primary pigments. In the principal pseudopupil, the black pigment is seen directly through the facet lens of the ommatidium, whereas in the accessory pseudopupils, the pigment is observed through the facet lens of the neighbouring ommatidia (Stavenga, 1979).

So, what's being seen are not the photoreceptors themselves, but rather pigment cells around the photoreceptors. That means the ommatidia in the accessory pseudopupils are not seeing out at sideways angles as I had thought. That makes perfect sense to me, particularly since it allows any number of accessory pseudopupils without requiring any modification of the retinal wiring.

My misunderstanding probably comes from reading about fly eyes, which have a somewhat different structure. Quoting from "The Insects // Structure and Function", by R.F.Chapman (4th edition, 1998), pages 587-588,

In most insects, the rhabdomeres abut on each other along the axis of the ommatidium forming a 'fused' rhabdom (although the cells are not actually fused), but Diptera, Dermaptera, some Heteroptera and some Coleoptera have widely separated rhabdomeres forming an 'open' rhabdom (Fig. 22.3). In a fused rhabdom, all the retinula cells within one ommatidium have the same field of view. In species with open rhabdoms each retinula cell within an ommatidium has a separate visual field, shared by individual cells in each of the adjacent ommatidia (see Fig. 20.21b).

On re-reading, I realize that there's probably no connection between the appearance of accessory pseudopupils and the sharing of visual fields described by Chapman. That was just a spurious connection that formed in my own head.

You learn something new every day, and sometimes you have to un-learn old stuff!

--Rik

[Yawns]

The kind of photo to get the top places in a contest ....

besides of the very peculiar scene, the composition and execution are superb...
Congrats...