Orbweaver - Philoponella oweni

Moved

Moved from Philoponella. Not a new species for the guide, but some great new photos & lots of new info. Nice.

… Lynette Elliott, 24 January, 2014 - 9:00pm

P. oweni

Based on range information and the length of leg I in comparison to the carapace I think this spider is likely P. oweni.

I put the image in photoshop measured the carapace and then measured leg I. Leg I came to almost exactly 5 times as long as the carapace.

Let's see what John & Jane think.

… Lynette Elliott, 24 January, 2014 - 8:38am

The rest of the description seems to fit also

arizonicus should be lighter without these heavy dark markings. It should be longer and flatter with the peak of the abdomen farther back, etc. We would agree with your choice of oweni

… john and jane balaban, 24 January, 2014 - 1:48pm

Moved

Moved from Spiders. Well so far all I've been able to figure out is that it should be either. P. arizonica or P. oweni unless P. semiplumosa has had a range extension. So, between P. arizonica & P. oweni I'm not sure how to separate them based on color or pattern. Both descriptions say they are variable. However, one difference is that P. arizonica as described as having posterior eye row nearly straight while P. oweni is described as having a slightly recurved posterior eye row. Also P. arizonica has its first leg 6.5 times as long as the carapace while P. oweni only has first leg 5 times as long as the carapace.

Other small points P. owneni is slightly smaller, P. arizonica has more distinct anterior humps and abdomen more flattened.

I'm going to try to measure leg I using photoshop tonight. Meanwhile I'm open to any opinions.

… Lynette Elliott, 23 January, 2014 - 9:28am

Thank you Lynette

I think it was on a dry branch of a weed or grass. Nearby were some Agave, Prickly pear cactus and mesquites; it was a little up on a hill, rather dry, but close to the edge of a more densely vegetated (dry) stream bed, about 1/3 of a km. from some buildings of the Santa Rita Experimental Station. I thought it was an egg sac because of the way it refused to leave it behind during the photos and it's general appearance, but it did seem rather large. Now I wish I'd taken more photos!
Thank you for all of your work and constant help - I've learned more about spiders because of you than anyone else!

… Lon Brehmer and Enriqueta Flores-Guevara, 22 January, 2014 - 9:12am

More info on eggs of P. oweni

found here though I don't think it helps us much.

… Lynette Elliott, 22 January, 2014 - 9:38am

Thank you

I've added all the additional views I have - some of them are not very useful. Feel free to frass any you don't need. Thanks again.

… Lon Brehmer and Enriqueta Flores-Guevara, 21 January, 2014 - 8:41pm

Great.

I just realized that the brown seedpod looking object in the photo could be the egg sac. I am assuming that its interesting shape could be helpful as well though so far I haven't been able to find much info about the egg sacs.

Egg sac info I found in Bradley 2013:
P. oweni - holds the egg sac with its legs until the young emerge
U. glomosus - egg case has an irregular lumpy shape, same color as spider

However since this family of spiders doesn't have venom they wrap their prey in many layers of silk then eat both the prey and the silk, so at this point I'm not sure the brown object isn't wrapped prey.

Can you describe the habitat a little more? Was it found near buildings?

… Lynette Elliott, 22 January, 2014 - 8:45am

Side View

Do you have a side view so I can get a clear idea of how many 'bumps' are on this spider's abdomen? Any other angles that you aren't already showing go ahead and post as well. At this point I think I'm seeing two sets of bumps, but I'm not positive.

My thoughts so far are that it does look like something in Uloboridae. According to NMSU the species we should find in AZ are Hyptiotes puebla, Philoponella arizonica, Philoponella oweni, Siratoba referens, Uloborus diversus, Uloborus glomosus & Uloborus segregatus.

With the long legs.. Hyptiotes is out.
Based on leg rings .. S. referens is out. (= Ariston referens pg. 19 Muma Gertsch 1964)

I have to be honest it does resemble Philoponella semiplumosa (=Uloborus variegata pg. 32)

Now that I'm thinking about this a little more that iridescence might be caused by a recent molt which could throw off the coloring of this spider.

... more notes coming as I have time

… Lynette Elliott, 21 January, 2014 - 6:15pm

Moved to Spiders

Moved from ID Request.

Cool Spider! I like the iridescent scales. I'll do some reading and give my opinion as soon as I have a decent one. =]

… Lynette Elliott, 21 January, 2014 - 5:18pm

Size

The combined head-body length would have to be a minimum of 6 mm, it could be more. I still have a hard time getting size down. Thanks!

… Lon Brehmer and Enriqueta Flores-Guevara, 21 January, 2014 - 1:49pm

Very interesting!

Wonder if this is a Uloborid in the genus Philoponella? Let's wait to see what Lynette thinks. Either way - Nice find!
What would you say for combined head and body length, 3mm or 10mm?

… john and jane balaban, 21 January, 2014 - 1:30pm