Moved from Spiders.

These two species are very similar and I'm not sure we can be 100% sure which it is. However, I think that based on the documented range maps and the fact that A. trifolium is much more common this is a good placement.

Moved from ID Request. I think that ID is correct, but I'd just like to look at it one more time (when I have my references) before moving it to the species page.

Some are easy to tell with marmoreus having those bright orange or bright yellow colors

while trifolium has brown or dull yellow


Marmoreus also often has a Christmas tree-like folium pattern that reaches all the way to the front and palisade-like rows of spots in the front


Trifolium seldom has that folium pattern and it usually fades out on the front. It has those four light spots on the dorsal area and only a single row of spots on the front.


but sometimes we're just not that certain, so we understand your question!


In our experience we also tend to find trifolium locally in open grasslands on large herbaceous plants while we find marmoreus in our woodlands. We'll be curious to see other responses to your question and see what insights others have.

Thank you John and Jane, your spider identification is very appreciated. One of the reasons I keep posting Araneus trifolium photos is that I am trying to distinguish between them and A.marmoreus. It seems that they both have variable coloration. What do you think is the most useful detail for separating them? Thank you again, 7Song

say Shamrock, Araneus trifolium.