8 replies to this topic

[Antennal_Scrobe]

How exactly do I tell the difference between the two species in the title? Currently, I call the normal black or red and black varieties C. nearcticus and the oddly colored ones with orange markings C. caryae. I know caryae has hairs on its face that are absent in nearcticus, but I don't think those are very easy to detect when they are there. The most interesting form I see is a subgenus myrmentoma major with a black gaster, orange mesosoma, and a reddish brown head. This I always call caryae. 

[Ferox_Formicae]

Literally the only way to tell is that C. caryae has punctures and hairs on the malar area while C. nearcticus lacks this. Color is almost never a good indicator of a species, especially species with such extreme color variation as C. caryae and C. nearcticus, both species of which can range from pitch black to red with a black gaster. Color varies between individuals from the same populations, even within the same colony.

[Antennal_Scrobe]

How closely would I have to look to see the facial hairs? Would a phone camera work? I like to use the video camera as a microscope without actually filming anything.

[Ferox_Formicae]

You have to look pretty close. I have an eye loop I use, but I occasionally use a microscope. If you have a macro lens, you could use that with your phone. They're pretty cheap.

[Antennal_Scrobe]

I don't have a macro lens, but want one. So it seems like you can't really tell without actual magnification equipment. So then I think I'll have to wait till next year for that first worker to die before I can identify my colony. I think I'll still call them cf. caryae though.

Edited by Antennal_Scrobe, September 2 2019 - 2:58 PM.

[Aaron567]

As Ferox_Formicae said, color has nothing to do with differentiating C. nearcticus from C. caryae. On queens or major workers the hairs should be somewhat prominent with the naked eye if light is reflecting off of them in a certain way. You'll see them very easily with a simple, cheap macro lens. Minor workers of caryae still have little to no malar hairs so you'll need to get a major or queen to identify them. 

[Antennal_Scrobe]

I keep trying to see if my queen has those hairs, I just can't tell. I wish C. caryae was better known, since it seems to have a wide range.

[Aaron567]

There are some good examples of the malar hairs in this Mississippi Entomological Museum article.

[Polyacanthus]

There are some good examples of the malar hairs in this Mississippi Entomological Museum article.

 

Thanks for this. I had the same question. Looks like I have nearcticus.