Spiders Celebrate National Moth Week

While I was conducting my mothing session for National Moth Week, some spiders decided to observe the week in their own idiom. When I put the black light out, I spend most of my time watching and photographing moths on the white sheet I hang next to the light. However, I also check potential moth perches away from the sheet — hosta leaves in the garden next to the sheet, the lattice fencing I hang the sheet from, the back wall of the house, and nearby trees. Two spiders had spun webs against the back of the house. When I first noticed them, they were simply lying in wait, but they soon moved to action.

The larger one, identified on BugGuide as Neoscona crucifera (a type of orbweaver), caught a moth larger than itself. The moth appears to be a noctuoid of some sort, but I would not be able to identify it to species without unwrapping it and depriving the spider of its meal.

The second spider is most likely a House Spider (Parasteatoda tepidariorum) or a closely-related species. It caught a small moth, probably a micromoth. This moth is so well wrapped that I am not even sure what superfamily it belongs in. Seeing these two acts of predation make me wonder how much my black light influenced the spiders' success. Were these moths blundering around the back of the house because their direction-finding capabilities were addled by the ultraviolet light? Or would these moths have been caught anyway?