Stoneflies!

[Ralph]

What the heck are these?? Found them in a trib to the Yuba and cannot figure them out in any key. Very small wingless adults.

[Tfisher]

Are you sure that's a stonefly? Looks more terrestrial based to me. Almost wasp-like or damselfly in appearance. I'll try and key it out using Merrit & Cummings sometime later, but am almost sure that it isn't from the Plecoptera family.

[Ralph]

Pretty positive these are stoneflies but VERY willing to be proved wrong!! Did Merrit (and some more recent keys) and hit dead ends. Thanks for any input!

[Chris Laskodi]

It's definitely a Coleopteran. The parts with the yellow dots are its reduced elytra. I've keyed out a beetle similar to this before. I remember it as a Staphylinidae. Check out couplet 5 in Merritt and Cummins for your answer.

[SHigSpeed]

Looks close:

http://bugguide.net/images/raw/U00020Q0W0R060Z07QQ0XQH0W0ORSQURG0YQ80Q020CRU03QFK 3QG0BR70R090K080UR3KDR3KBR70.jpg

Rove beetle.

I think it's certainly not a stone, more likely a beetle family bug like Chris mentioned.

I couldn't find it here but it's probably in there somewhere:

http://bugguide.net/node/view/60

_SHig

[Ralph]

You are right, they are adult rove beetles (Genus Stenus). I found these amid stonefly husks of the same size underneath stream side boulders. This winter I caught a bunch of Utacapnia tahoensis for BYU and the general shape, size, and behavior are similar. My search image was pretty biased. Thank you for the correction!!

This is from Dick Baumann (Dr stonefly at BYU) after he looked at the photo:

"I once had a German colleague tell me to collect Stenus when I was in the field. I asked him if there was an easy way to tell them from micropterous stoneflies. He said that when you uncover the beetles they look up at you with their big eyes in an inquisitive way instead of running away to hide as quickly as possible."

[CPasley]

Beetle larvae - appear to be the predatious type.

[Ralph]

Steve Heydon at the UC Davis Bohart museum of entomology believes these are Dianos rather than Stenus. Apparently they don't clearly key out and need to be turned over to some poor grad student to dig into the taxonomy. Nothing to do with fishing, but cool regardless.

[Bob Laskodi]

UMMMM, Ralph, that would have been Chris. He worked in the UC Davis Museum of Entomology while at UC Davis!!!!

[Ralph]

UMMMM, Bob, I've known Steve Heydon for a long, long time and even hunted bugs in Borneo with him. Even at my infirm state of derangement I doubt I would confuse Steve with anyone else. Chris probably worked for Steve who is the museum curator.

[Bob Laskodi]

Ralph, you misinterpreted my message. Chris was the poor student doing the classifications in the museum and yes he did work for Steve.

[Ralph]

If Chris doesn't already know, Stella passed away a couple of weeks ago. Quite sad. I spent a month in Malaysia with Steve and Stella - it was their first real date. She never complained about the swarms of sweat bees, knee deep mud, cobras or kraits and after that she still married him.

[Bob Laskodi]

Sorry to hear that bad news. Chris has been out of Davis for two years now and has not kept up contacts. Chris did a lot of the classifications for aquatics in the entomology museum, and IIRC, a lot of the CALIF specimens in the museum (aquatics) were from his personal collections.