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Darkling Beetle - Calosoma peregrinator

Darkling Beetle - Calosoma peregrinator
San Pedro River Valley area, SE of San Manuel, Pinal County, Arizona, USA
July 25, 2011
Size: approx 15-20 mm
Sonoran Desert area, many Creosote bushes nearby, comes to light at night, elev 2800 feet

Images of this individual: tag all
Darkling Beetle - Calosoma peregrinator Darkling Beetle - Calosoma peregrinator


Moved from ID Request.

C. peregrinator?
I'd guess C. peregrinator which I've collected near there, except for the fact that C. peregrinator would be a little larger than your estimated length.

I seem to be missing the correct size
often on my estimations. I apologize - I still haven't figured out a good way to incorporate getting a good estimate into my process - something to work on. I'm trying to get better at this. Thank you for your help!

estimating size not easy
I am not so good at it myself, it is a skill you learn if you keep measuring stuff and get a feel for what a 20mm bug looks like!

it's not easy indeed, and takes years of practice
for identification purposes, only accurate measurements are helpful, while the estimates are, more often than not, misleading --so i would recommend leaving the size field blank wherever no measurement data is available.
that being said, Lon's estimates amaze me --in a good way, too!!-- in that he, unlike the vast majority of nosotros humans, tends to underestimate the size, while the 'ordinary people' do the opposite: BG submissions with size data hyperinflated x2-3 times is painfully common

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