9 replies to this topic

[Voidley]

So I’ve got this one Lasius neoniger queen who I’m going to take out of hibernation soon. However, it seems like this queen can hardly wait!

 

 

For reference, here is a photo of this queen before diapause. Looks pretty normal, right?

 

Well, this is her now…

 

Her gaster literally looks like it’s about to explode.

 

I really thought that she was infected with a parasite or something. And honestly, that still isn’t off the table, But when I zoomed in on her you can actually see the individual eggs that she’s producing, so I think that she is just super physogastric. Hopefully, her first batch will do well.

 

Here is the closeup photo of her gaster. It has expanded so much that the thin membrane is practically see-through. Look closely and you can see each egg clustered inside.

[ReignofRage]

Contrary to what people usually say, those are not eggs. Rather, they're lipid stores that develop in the queen. Gynes still have ovaries, ovarioles, and oviducts; not some alien system where they fill with eggs that are outside of any organ. Fedoseeva & Gretsova (2020) explains the processes, development, and other changes in founding gynes along with summarizing numerous other studies on the topic. A breif quote:

 

"The fat body contains numerous lobes and clusters of cells. Its periphery is comprised of a parietal layer adjacent to the body wall, and a layer that surrounds internal organs called the perivisceral layer [Schwanwitsch, 1949]. The fat body is most conspicuous in the abdomen, but some portions of the organ extend into the thorax and head [Chapman, 1998]. In imagoes [sic], perhaps this is the most dynamic organ since its content and size changes throughout the life of an insect."

 

Soon after this quote, it explains two different modes in which the wing muscles of a gyne will break down and ultimately become adipocytes.

[ANTdrew]

Make that your profile pic.

[GOCAMPONOTUS]

Will you make a journal?

[bmb1bee]

I wonder why the abdominal segments on queens sometimes appear to have peeled off. I found a couple Prenolepis imparis dealates like that last year, so I’m guessing it’s either from a molting defect or some sort of injury.

[Voidley]

Contrary to what people usually say, those are not eggs. Rather, they're lipid stores that develop in the queen. Gynes still have ovaries, ovarioles, and oviducts; not some alien system where they fill with eggs that are outside of any organ. Fedoseeva & Gretsova (2020) explains the processes, development, and other changes in founding gynes along with summarizing numerous other studies on the topic.

Very interesting! I guess you learn something new every day. So is this something that only really happens with Lasius, or does it also occur for other physogastric insects? Does this still mean that this L. neoniger queen is not really physogastric? or is it just that they always have these fat bodies but they are only visible when the queen is physogastric?

 

 

Will you make a journal?

I wasn't planning on it. I have thought of making journals for my colonies in the past, but I've found that documenting everything ends up sort of discouraging me from even checking on the colonies, and it ruins a lot of the fun of antkeeping for me. If I do notice something particularly noteworthy, I just take a photo of it and maybe make a small post about it—but that's it. I may make a journal if I find something really unique or interesting, but at least for now most species I keep are common and have already been thoroughly journaled.

 

 

I wonder why the abdominal segments on queens sometimes appear to have peeled off. I found a couple Prenolepis imparis dealates like that last year, so I’m guessing it’s either from a molting defect or some sort of injury.

In the case if this queen it was an injury from when I was catching her and putting her into a test tube. At first I was worried that she might not make it, but it seems that these kind of injuries are pretty common and many people have had succesful queens even with these kind of injuries. I mean, this one seems to be doing quite well.

[ReignofRage]

Physogastrism is not restricted to Lasius or ants for that matter and occurs in many insects and other "bugs." The amount of adipocytes is always changing, but they are always present - they only being notabe when a gyne has developed a lot of them as is the case for your gyne.

[gcsnelling]

A possibility that no one seems to have mentioned, unless I missed it is the possibility of a parasitic infection. I have seen infected ants on many occasions.

[dspdrew]

If it is parasites, I guess they should come bursting out soon enough.

[OhNoNotAgain]

I know I may be totally wrong, but I associate extreme physogastric appearances to possible egg-laying issues. It happened once with a proven Liometopum queen I had, with an established colony. She stopped laying and instead her gaster ballooned as per your photo. As I often have pet birds I am aware of things like egg-binding and got pretty worried. Eventually that Lio queen died without having laid any new eggs. When I saw one of my Camponotus also becoming overly physogastric, I actually took her out (she only had a couple workers so that was easy), put her in a plastic bag, and did some gaster massage (at the egg-laying end) with a toothpick ... yeah, I know, possibly silly. Either way the condition went away soon after that. P.S. I have some idea of what's normal for the species I mentioned so I could tell when it was getting abnormal.

Edited by OhNoNotAgain, March 27 2024 - 5:52 PM.