L. hesperus is classified under:

·         the Domain Eukaryota because they have organ-bound organelles

·         the Kingdom Animalia because they are heterotrophic and

·         the Phylum Arthropoda because they are bilaterally symmetrical, segmented and paired, jointed appendages. They also have an exoskeleton and grow by molting.

·         the Class Arachnida because they only two body regions that join at a waist

·         the Order Araneae because they prey on other organisms with a pair of chelicerae

·         the Family Theridiidae because they have a comb of bristles on their fourth leg that they use to control the sticky string web they produce.

·         the Genus Latrodectus because their differentiated sex organs from other species

·         the Genus Species Latrodectus hesperus because it’s found in the Western part of North America.

This taxonomy was found here.

The following phylogenic tree is a specific classification of the different species within Latrodectus and is based upon cytochrome oxidase I sequence.

taxon links

As you can see, there's a lot of work to be done in classifying the many different species of Latrodectus!

Here is a broader tree to give you an idea as to where L. hesperus stands in comparison to other Arthropods also in the subphylum Chelicerata:

Arachnid Tree closeup

This website, from which the above phylogenic tree was taken, also has an AWESOME animation of what the Chelicerates may have looked like as they evolved. Take a peek if you have time!!

Where are spiders in comparison to us (mammals)? The next tree demonstrates that.

Finally, to bring it all together, here's the broadest tree you can get.