Male Leaf-Curling Sac Spider

2021 May 2

This leggy male spider was on our house siding on June 9, 2020.


I can tell he’s a male because his pedipalps have enlarged tips, which is characteristic of male spiders.


He also has smooth, glossy hair on his abdomen, slightly projecting spinnerettes, a reddish-brown body, and a black face. And, his eyes are a continuous row of 6, plus 2 more above, and the two upper eyes reflect light the same way as a cat’s eyes do [1].


He’s a dead ringer for Clubiona canadensis, one of the “leaf-curling sac spiders”. These are the ones that curl up a leaf into a refuge, and then pounce on prey as it ambles or flutters past. This isn’t my first picture of what looks like this same species, I also have one from June 2015 that looks pretty darned similar. Same time of year, too. Which implies that early June is when the males abandon their rolled-up leaves and go out looking for the females.

[1] If you go out into a yard at night, hold a flashlight up beside your head, and shine it into the grass, you can see the reflections from the wolf spider and sac spider eyes, glimmering back at you like tiny little gemstones in the darkness.

One Response
  1. May 7, 2021

    Nice photography, but an unattractive beastie. I do like the idea of the flashlight, though I don’t have much of a chance to practice it in San Diego.

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