Question about sampling/pinning/drying

tsfields

tsfields

Egg
Hi all,

I am working on/for a grazing ecology research project this summer, on a bison ranch. I decided to do a little personal collecting in the field today, and I had some things happen that I'd like some expert input on, as I'm pretty new to insect collecting. I worked on this project last summer, and part of my job was trapping and identifying dung beetles, which got me very excited about insects—dung beetles especially.

Anyway, I collected quite a few Aphodius spp., among other things, from bison dung pats today, and stored them in alcohol, in a whirl-pak, in the glove-box of the side-by-side I was driving during the afternoon in the field. This is the only way I could really store them, at least with the "equipment" I have at the moment. Later in the day, I was examining my specimens in their bag, and I noticed that a number of them seemed to be stretched or bloated between the head and thorax, and the thorax and abdomen. Also in the general area of the genital opening. I'm sure there's a term for this, but I don't know it. In one case, it was prolapsed, but I didn't take a picture of that.

See connection between thorax and abdomen of Aphodius fimetarius (I think, not certain):

Aphodius fimetarius 1(1).jpg

And the genital area of an as-yet-unknown dung beetle (please forgive the low-quality; I had to compress and trim to all heck to make it small enough to upload):

beetlesnip.PNG

The two questions I have are: will this return to normal/shrink back up as the beetles dry? And: is there a way to prevent this when in the field for a long time?

Thanks everyone.
 
Yes, it will usually go back to normal. This is commonly seen in dung beetles and other beetle species attracted to animal feces. During summer collecting, high temperatures can cause the specimens to start decomposing very quickly, which makes them appear bloated like a balloon. Even if you collect them and immediately place them in alcohol, the heat in the field can still cause this to happen. Once the specimens are properly prepared and dried, they typically return to their normal shape.

By the way, your first picture is between prothorax and mesothorax, not abdomen.
tsfields said:
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Click to expand...
 
Jkim, thanks so much for the info! That is relieving to know—and I'm glad I didn't mishandle them in any way. Thanks, too, for correcting me on the body segments. No worries if not, but would you happen to have a diagram for this? The key to the Scarabaeoid beetles of my state has a detailed diagram of parts/terminology, but it doesn't name the body segments. Just want to make sure I know what I am looking at in the future!
 
tsfields said:
Jkim, thanks so much for the info! That is relieving to know—and I'm glad I didn't mishandle them in any way. Thanks, too, for correcting me on the body segments. No worries if not, but would you happen to have a diagram for this? The key to the Scarabaeoid beetles of my state has a detailed diagram of parts/terminology, but it doesn't name the body segments. Just want to make sure I know what I am looking at in the future!
Click to expand...
How big are those?
 
tsfields said:
Jkim, thanks so much for the info! That is relieving to know—and I'm glad I didn't mishandle them in any way. Thanks, too, for correcting me on the body segments. No worries if not, but would you happen to have a diagram for this? The key to the Scarabaeoid beetles of my state has a detailed diagram of parts/terminology, but it doesn't name the body segments. Just want to make sure I know what I am looking at in the future!
Click to expand...
Diagram can be found HERE. I must have deleted accidentally:ROFLMAO::ROFLMAO: before posting, but I actually intended to write: "By the way, your first picture is between prothorax and mesothorax (not a common term used), not abdomen."

I'm glad to see someone in the forum posting thread from research-end. I used to love seeing Aphodiinae under microscope when I was a student. Although I gave up identifying species level after some, I still have bunch in drawers waiting to be id-ed some day...
 
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