Swift Crab Spider in Yellow

Moved

Moved from Spiders.

… john and jane balaban, 31 October, 2015 - 8:36pm

Moved

Moved from ID Request. The only other one I think we need to consider is M. oblongus.

… Lynette Elliott, 22 July, 2015 - 11:47am

Testing for Misumessus oblongus

This is from the info page for the genus Misumessus:
(1) Posterior of abdomen is diamond-shaped and not rounded. = FAIL
(2) Posterior of abdomen has a look like it's made of stacked layers, the way Misumenoides formosipes abdomens do. = FAIL?
(3) Abdomen is somewhat flattened and has a sense of projecting more away from the cephalothorax than over it ("oblong"). = FAIL
(4) The Misumessus in my area... = ?
(5) Like Misumena, but unlike Mecaphesa, Misumessus has a pattern of apodemes (dimples) on the abdomen. = FAIL

After looking at this test, what do you think, haha? Thanks

… Bob Biagi, 22 July, 2015 - 2:13pm

=] abdomen

tests often can't be used when the spider is gravid. Any front views of the eyes? For what it's worth I'm not really thinking it's Misumessus.... just making sure we've considered everything.

… Lynette Elliott, 22 July, 2015 - 2:56pm

alternatively

maybe an all yellow Misumena vatia?? BugGuide has only a few photos of Mecaphesa celer but the area around the eyes in M. vatia seems to be colored more like your spider than M. celer – I think (famous last words).
Either way it's a win because you either have something BugGuide has only a few photos of or you have BugGuide's first Arizona record for the other.

I guess we'll see what the experts call it. As long as it doesn't turn out to be a grasshopper, we're both okay

… Steve Scholnick, 21 July, 2015 - 8:49pm

Ruled it out already!

Steve, I looked at those spiders and ruled them out based on:
1) lack of large abdominal dimples
2) overall hairiness, mostly around the eyes
3) abdominal trapezium (4 to 6 pale dots) point or converge toward the spinneret.

Thanks for your assistance!

… Bob Biagi, 21 July, 2015 - 9:14pm

thanks

for the pointers, much appreciated

… Steve Scholnick, 21 July, 2015 - 9:34pm

thanks

but which did you rule out? I assume it was M. vatia. Which characteristics did you use to rule it out - I might as well learn something

… Steve Scholnick, 21 July, 2015 - 9:21pm

I was editing, sorry!

Also, if you check, the image for the yellow spider on the info page for Misumena vatia is now placed in Misumessus oblongus, haha! That was confusing.

… Bob Biagi, 21 July, 2015 - 9:27pm

this one's almost all yellow

, almost anyway :-)
I was actually looking at plate 74 in Bradley's Common Spiders of North America(1) which shows an all yellow M. vatia among other variations. It's a good book but, to be honest, I've been fooled by those illustrations before. The colors are sometimes off in confusing ways

… Steve Scholnick, 21 July, 2015 - 9:39pm

Great one from Lynette!

Yes, that is a good image for that species. You can see five large dimples and also two smaller ones, with two more little dots closer to the spinneret. Now, check the two in the middle of the abdomen and the two just below them, that form a squared box shape. These are the points where the trapezium dots show up. Sometimes they are dark spots and sometimes they are pale spots. This image shows them a little clearer than mine and you can see the shape of it better:

Also, the overall shape of the abdomen is more ovoid than most of the related genera and it rises farther above the carapice.

… Bob Biagi, 21 July, 2015 - 10:02pm

Thanks!

… Steve Scholnick, 21 July, 2015 - 10:23pm