Araneae: Theridiidae: Latrodectus hesperus Chamberlin & Ivie, 1935, (Western Black Widow)

The female's occasional practice of devouring the male after mating has earned this species its name.

The sexes differ greatly in appearance: males are small (1/2 in., or 13 mm, in body length) and grayish black in color, with variable marks of red and yellow spots and stripes; females are alrge (1 to 1 1/4 in., or 25 to 32 mm, in body length) with very bulbous shiny black abdomens. Both sexes usually display a red spot shaped like an hourglass on the underside of the abdomen, although this mark and the rest of the color pattern varies from individual to individual.

LACM photograph

the Black Widow is all too common in the basin and likely to be found in any cool dry protected hideout. Favorite haunts are hollow stumps, woodpiles, crawlspaces under houses, and refuse stored in garages and attics. The web is made of rather coarse silk and is without definite form.

Although they are not at all aggressive, males and females occasionally bite people, often causing serious and even tatal consequences. the venom is reputed to be proportionately fifteen times as poisonous as that of the rettlesnake. For this reason, one should be very careful to avoid the spider and should immediately call a physician if bitten. First-aid treatment cosists of placing an ice bag on the wound and keeping the patient calm until the doctor arrives.

© 1993 Insects of the Los Angeles Basin