Recently I have become fascinated with spiders, and in particular the Black and Yellow Garden Orbweaver spiders (Argiope aurantia). I’ve spent an amazing amount of time observing them and their webs. Already I have posted photos of the spiders themselves, their webs, and several types of prey that they have captured and wrapped in silk.
This past Monday I observed what I think was a spider actually feeding on a victim that I can’t quite identify. For some reason I used to think that spiders ate solid food, but now I understand that they have a mostly liquid diet. According to an article at earthlife.net, the mouth parts of these spiders have a serrated edge to cut into the prey and a filtering edge covered in fine hairs that prevents solid particles from entering the spider’s mouth. This filtering system is so fine that only particles smaller than 1 micron (0.001 of a mm) can pass through. The spider’s venom has enzymes which can help liquify the insides of a victim and the spider may also excrete digestive juices onto the victim. Spiders then have a sucking stomach that helps them ingest the liquids.
Argiope aurantia feeding on captured prey
Sharp-eyed viewers will notice that I rotated the image 90 degrees counterclockwise to make it easier to see what is going on. Note the positions of some of the spider’s legs as she cradles her victim. If you click on the image, you will get a higher-resolution view of the spider. My apologies if I have been too graphic in describing this spider’s digestive process.
© Michael Q. Powell. All rights reserved.
Mike Powell 