The identification of this spider is based on the Southern California location where the other similar species of Latrodectus (L. mactans and L. variolus) are unlikely and the judgment of a Cal State Fullerton professor who saw a picture of the spider and identified it as L. Hesperus.

The other images linked to here are different views of the same spider. This spider was observed to reside in the web of a dark colored female black widow for the period of about a month. Another more darkly colored L. hesperus male was observed to reside in the same web during the same time period.

The large disks on the end of the spiders pedipalps are used by the male spider to transfer its sperm to the female.

The body of this spider was about 7mm long.