Long-Jawed Orbweaver

2016 September 28

While I was bicycling home on June 20, 2016, I saw this large and excellent spider hanging out on the handlebars. It liked to rest with its legs stretched out in a line, which on a plant stalk or tree trunk would have made it really hard to spot.


The text it is sitting on is standard 12-point type, so its body is close to half an inch long, and the total legspan is around one and a half inches. This is a pretty big spider.


Looking at the face, we can see that the chelicerae (the jaws) are quite elongated, and the pedipalps (the appendages around the mouth that resemble short legs) are thin and threadlike.



The abdomen is pretty elongated as well, and it looks like the underside of the abdomen is completely black.


This is most definitely one of the Long-Jawed Orbweavers, family Tetragnathidae, and more specifically the very elongated ones in the genus Tetragnatha. I have photographed spiders in this genus twice before, but the first one was a very different color (and probably a different species), while the second one was much thinner (and may have been either an immature, or a male).

There are 15 known species in this genus in North America, but evidently they are so variable in size and coloration that they are very difficult to distinguish in photographs. At least, the people on BugGuide mostly aren’t distinguishing them. Anyway, while they are harmless to humans, the fact that I’ve found two out of the three pretty much by accident (and one by blundering into its web) suggests that they are somewhat more likely than average to suddenly turn up crawling around on a person. Which, since they can be quite large, probably leads to a certain amount of distress in people that don’t like spiders crawling on them. But, fear not. Just go outside and chase them off, and you’ll be fine.

One Response
  1. Mark Sturtevant permalink
    October 7, 2016

    Those are good pictures! I have taken some pictures of these recently. The jaws make them look really scary, but they are really benign.

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