Insect Picture of the Day

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Platycryptus undatus! This is one of my favorite spiders. (I showed one of these last year.) In the picture last year, I mentoned that they have a very recognizable chevron pattern down their back. This female is somewhat small and her chevrons aren’t perfectly delineated, but you can sort of make them out nonetheless.

This spider has been living inside the screen of the stairwell of my house. I kept meaning to catch her and release her outside, because houses are like deserts to hunting bugs: there’s often no water, and little prey. When I cornered her to catch her, she looked right at me and said “Hey! I’m doing just fine here without your help, bozo!”

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You can sort of tell she’s saying that from this photo. See how wide her abdomen is? What you can’t really tell from this picture is that her abdomen is swollen upwards as well as side-to-side: this means that she is very pregnant, and that means that she is getting plenty of water and prey!

I left her in the window. As of this writing, that was a week ago, and she’s still up there. I kept an eye out for prey, and it turns out that in the morning light, any bugs that got into the house overnight move to the East- and  South-facing windows. The stairwell faces South, and sure enough, it’s a spider bed and breakfast!

That didn’t explain the water situation, though. She is clearly getting it from somewhere: unlike orb weavers, jumping spiders can’t get all their moisture from their prey, and have to augment their diet with fresh water. Then it hit me: that window is directly above one of the sprinkler heads on my lawn. Three times a week, I spray water on her screen for several minutes!

So there you have it. Cute, adaptable, and obviously smarter than me. That’s why I like Platycryptus undatus.

P.S. She’s about 7mm long. Big enough to qualify as a “big” spider if you’re afraid of them, but small enough to qualify as a “cute little spider” if you’re not.