Nutrition
The L. hesperus is a carnivore that eats mostly from the orders Coleoptera (beetles) and Hymenoptera (ants, wasps and bees) although they do eat other organisms such as grasshoppers and even other spiders (Salomon 2011, Drees and Jackman 1999). There still has not been a lot of research done on their diet but it is certain how they eat.
Both
photos by Richard Greene
Widow spiders are not fast eaters by any means. Once their victim gets stuck in their extremely sticky and strong web, the spider rushes out to further entrap them by spinning more web and using specialized comb structures on their fourth tarsus (seen below) to throw it around various parts of the victims body (Smithsonian National Museum of Natural History 2012).
Photo by Jeremy Miller
Only when completely
immobilized, the spider bites their victim and the strong neurotoxin
venom (which is 15 times stronger than a
rattlesnakes!) injected kills the prey in about ten minutes. In the meantime, the spider
continues wrap their prey with web. Once movement ceases, the spider then releases enzymes to start digesting the prey. In
nature, the spider would then drag its prey into a more secluded
"retreat" area to either store it until the spider is hungry or feast upon it.
When Latrodectus hesperus eats its prey, it siphons out the
inside material, that has been liquefied by the enzymes, and leaves
the outside of the prey intact, like a shell of what it used to be
(Animal Diversity Web 2001).
Here are a couple fantastic YouTube videos of female black widows in
captivity capturing prey: