Brachiacantha ursina? - Brachiacantha felina

more evidence for B. felina

I realize I'm late to this party, but I'm on an ursina group kick today :)

Range - Nothing else in the ursina group is in Kansas at all; Douglas Co. is right smack in the eastern part of the state where B. felina occurs.

Size - Females of B. felina are up to 3mm long, like this one. Females of B. ursina are up to 4mm and B. decempustulata are not larger than 2.5 mm.

… Abigail Parker, 10 April, 2011 - 1:02pm

B. ursina group,

but may or may not be B. ursina. Gordon's ref.(1) lists about 12 species in the ursina group. Kansas appears to be in ursina no-man's-land. Most species have distros that stop east of Kansas (including B. ursina itself), a few to the south, and a couple to the west. Now distributions have a tend to be incomplete and changing, and obviously yours is proof of that. But your location also means the number of possibilities are greater, not fewer. If you can get a good frontal head photo, I might be able to get to a species (let's hope for a male, which have more distinct markings on the head). Otherwise, it might have to wait for an expert. The good news is that it may not be ursina, and thus a new species for the Guide.

… Tim Moyer, 30 October, 2007 - 12:35pm

I'll work on that soon!

I'm really busy till Thursday, but after that I'll have some leisur time to image specimens Thanks a lot!

… Will Chatfield-Taylor, 30 October, 2007 - 3:26pm

B. felina

thanks for the head shot. The lack of any yellow on the apical pronotum margin, and a little bit of brown/dark yellow around the eyes points to this being a female (a male would have been easier to determine). Based on size, shape, and everything else, I believe this is B. felina (Fabricius). The shape appears to be more round than oval - please confirm. And the size should be no larger than 3.0mm - please confirm. I reviewed my Kansas geometry to find where Larwence was (my apologies for being ignorant). And as it is close to the eastern boarder, this does fall just within the distribution pictured for B. felina. B. ursina makes it to northcentral Missouri, but not reaching the Mississippi. B. felina does have a wide distribution - east to the atlantic (Virgina Beach to Boston, north to Michigan (not UP), and south to Louisiana. So eventually someone else should find one too (even myself).
So if you can confirm the above observations, I'd say we have another new species for BugGuide :)

… Tim Moyer, 31 October, 2007 - 12:15pm

Thanks!!

Yes, the one thing that really struck me about this was how round it was compared to the other species in this, and it is around 2-3mm. Thanks a lot for all the effort you put into thio]s! I'm going to go ahead and create a page for it. Thanks again

… Will Chatfield-Taylor, 31 October, 2007 - 2:07pm

You need to stack imagesu

using only the in-focus parts of each image. You can do this manually or with a photo montage system.

… Jim McClarin, 23 October, 2007 - 9:13pm

stack who with the what now?

Um.... so take a bunch of images at different focuses and then layer them? I've never heard of that, sounds like a good idea though!

… Will Chatfield-Taylor, 23 October, 2007 - 11:43pm

See Forum discussion

Stacking Images.

… Jim McClarin, 24 October, 2007 - 2:01am

A problem arises

I don't know what f-stop, aperature, or any of these terms mean... I've never actually had a photography class

… Will Chatfield-Taylor, 24 October, 2007 - 2:15am

Ah, well then,

you might be able to get a bit more of the critter in focus by learning about and using the aperture setting on your camera. Set the aperture to the highest number, whatever it is (8 or 11 most likely but possibly higher). This will reduce the opening through which the light passes through the lens into your camera. It simultaneously will increase the focal depth, allowing you to get more of the subject in focus. You will have to boost the output of your ring flash to compensate. Play around with it and see what results you can achieve that way before considering image stacking.

… Jim McClarin, 24 October, 2007 - 5:44am