Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Upcoming Events

National Moth Week photos of insects and people. Here's how to add your images.

Photos of insects and people from the 2019 BugGuide Gathering in Louisiana, July 25-27

Discussion, insects and people from the 2018 gathering in Virginia, July 27-29

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Photos of insects and people from the 2014 gathering in Virginia, June 4-7.

Photos of insects and people from the 2013 gathering in Arizona, July 25-28

Photos of insects and people from the 2012 gathering in Alabama

Photos of insects and people from the 2011 gathering in Iowa

Mystery Paederinae - Sunius rufipes

Mystery Paederinae - Sunius rufipes
Great Smoky Mountains National Park (I have a permit) County, Tennessee, USA
October 1, 2007
I've been going through leaf litter samples from Great Smoky Mountains National Park and by far the most numerous species (about 700 specimens) is a Paederinae of some sort. I've forced everyone in the lab to look at it. We think it's in the genus Sunius, but can't get it to a good species.

Visit for more pictures.

Images of this individual: tag all
Mystery Paederinae - Sunius rufipes Mystery Paederinae - Sunius rufipes

Moved from Medonina.

Lee Herman says this is Sunius rufipes (Casey).

Moved from Paederini.

Moved from Paederinae.

Lathrobium sp. but in case, c
Lathrobium sp. but in case, check out the elytra from the side in lateral view. If you see a line cutting across the side margin of the elytra, then it's a Labrothium, but I'm gonna bet my lunch money it's a Lathrobium. This genus is huge and difficult to tell apart. There are no comprehensive works. I would just say Lathrobium sp. X. There are a few papers that have tackled subgenera of the genus but I couldn't tell you how to ID to subgenus. Maybe there is a European work that will help you with that.

not Lathrobium nor Lobrathium
Paederini is correct, but it's in the subtribe Medonina (quadrate pronotum) rather than Lathrobiina (elongate pronotum, except in two southwestern US-Mexican genera). Lathrobiina also have apical ctenidia on the metatibia both anteriorly and posteriorly, as another comment alluded to, but that area's out of focus in the photo. I'd guess either Sunius or Medon, but you need a ventral view to see the gular sutures to separate those. (Or at least I do - I haven't seen enough of either genus to be really familiar with them.)

hind tibia ctenidium?
I'm just an amature, but keying using American Beetles, it appears that it could key to Sunius. But Lathrobium and Lobrathium also appear to be an option, at least from what I can see (or can't see) in the images. The key splits these using the ctenidium on the hind tibia - "well developed on both posterior and anterior face" for Lathrobium and Lobrathium, and "without well developed ctenidum on anterior face, thought usually present on posterior side". Perhaps I'm missing it, but I can't tell from the images which way yours is trending. I don't have access to a lot of collection material, but from the MCZ's type images, at least some of the Lathrobium and Lobrathium look similar. But MCZ doesn't appear to have much under Sunius to compare to.

Also, I did find Casey's 1905 ref. on-line, and from a quick key it looks like either S. binotatus or S. brevipennis might be possibilities. But I didn't get to study his reference, and it appears like he may have species listed under other genera which are now included in Sunius.

So I'm perhaps of little help, but the effort was fun :)

Probably not Lathrobium or Lobrathium
Under the big scope a case can be made that there is a complete hind tibia ctenidium, however, American Beetles says “well developed”. Just in case we tried a paper by Watrous (1980) on Lathrobium. In his diagnosis of the genus he mentioned asetose eyes (this specimen has small setae on the eyes), and a short prosternal intercoxal process (his figure shows one about ½ the length of this specimen). Plus his well developed ctenidia is very obvious.

All of what Casey (1905) calls Sunius have been moved to different genera! All of what we call Sunius now are under different genera in Casey.

It’s a fantastic puzzle.


spongymesophyll !!
We've always been fascinated by the palisade layer! Sorry, don't know the beetle, but couldn't resist.

Comment viewing options
Select your preferred way to display the comments and click 'Save settings' to activate your changes.