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Photo#431147
Adult female - Phylloneta impressa - female

Adult female - Phylloneta impressa - Female
Whitecourt, Alberta, Canada
July 22, 2010
Size: BL ~ 4-5 mm
I'm putting this under T. impressum for now, based on the general abdominal pattern, size, web type with the typical cup-like retreat formed out of bits of vegetation and remains of prey, and the blue egg sac, all consistent with others of this species I've found in my area. The colors are different on this specimen, though. Compare with the more "usual" specimen I'm used to seeing:



These spiders are interesting in that the young stay with the mother through several molts and often for many weeks after hatching. She lets them eat from prey she captures during this time. The female doesn't live long after the spiderlings hatch, maybe a couple of weeks, and the young remain in her web after she has died. I have found juveniles almost as large as the mother, still in her web, a few weeks after she has died. No evidence yet that they make a meal of her.*

It will be a while before I can verify the species ID on this one by the epigyne. I have to let the babies hatch first so that nature can take its course.

The web was constructed in the dead outer twigs of a raspberry bush, about 2 feet off the ground. She will add to and enlarge her retreat with the remains of future prey, and it will soon be large enough to shelter her upcoming brood. I took the picture from underneath the spider, looking straight up.

[* - After posting these remarks, a female I had in the lab was eaten by her spiderlings. They'd been in her web for a few weeks, and sharing her food. Then, one day they basically swarmed over her, and though she struggled they were overwhelming and she soon died and was eaten. The spiderlings had been fed regularly before they did this, so why they suddenly turned on their mother is a mystery. Of the maternal webs I've found in the wild, and visited regularly over a period of several weeks in each case, the young usually molted through several instars while the mother was still alive, but I noticed no hostility from one to the other.]

Should the page for Theridion impressum
be deleted?

 
..
I thought I'd leave it for a while so that anyone looking for T. impressum will find a link there to the new name and guide page.

 
..
I don't know if there is a better way to do this, but this (maintaining the old page) is useful, otherwise links to the species become broken. I suppose the alternative is to maintain the same node number (the BG number) and then modify the taxonomic information as necessary? Perhaps that would be better? But is it possible? Or preferable?

In my own database I do both. In somecases a "page" remains, but is assigned "synonym" status (changes heading color, among other things), so that one can click through from the synonym page to the current name. In other cases (e.g. a species is moved to another genus), I simply update the information on the current page and add the old genus name to the.. "old genus names list".

 
T. pictipes was also moved to Phylloneta
in 2008. I moved it here and I'm doing a little experiment to see what happens with the links. I'll let you know what I find.

Edit ~ I followed every link that the search brought up. As long as the link was to the species images page it brought me to the new Phylloneta page. However, if it was linked to the genus page.. of course that still take the person to Theridion. None of the links were 'broken'.

Moved

Moved

Wow -
great photo and natural history information, John!

..
The amount of black pigment in this holarctic species also seems to vary quite a bit. Nice observations.

-K

Quite "impressive"
indeed! Lovely

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