Black Widow, Latrodectus hesoerus     * * images of  female, immature and male * *

Mature female latrodectus hesoerus in webAdult female Black Widow Spider
left - Mature female Black Widow
right - Female with penny for size comparison
In nature, and especially at Kaweah Oaks Preserve, never put your hand into a squirrel, rabbit or other dark hole in the ground or tree. This is the most likely habitat for hungry Black Widow Spiders. Their bite is painful and is the most toxic of all spiders in the Central Valley. Its poison can cause flu-like symptoms and, in severe cases, liver damage - especially in young children or the elderly.
Luckily, they are very sensitive to insecticides and, therefore, easy to control.

Immature Black Widow
immature Black Widow found on a wall same baby widow in a plastic container

Immature Black Widows have the same shape as the mature "Widow" but with dramatic color markings. An immature Widow, although much smaller that an adult, can still cause a painful and dangerous bite. As you can see, the characteristic hourglass marking is yellowish, not red, in this young female spider. After mating, the female spider takes on the sinister black with red hourglass coloration.

The Male Black Widow Spider
adult male black widow spider
adult male black widow, retains youthful makings
This male specimen was found on the outside of a neighbor's home
in mid-October, well after mating season. So he either did not mate
or was faster (or smarter) than most of his species.
left - the adult male Black Widow

The hourglass marking is faint, but discernable. 

Mating is usually the last activity for a male Latrodectus hesoerus, and he generally never escapes to tell the tale. The female rewards the male by killing and eating him after mating. That's why she's always a...

"Black Widow."

a note from Marjorie Moody about male black widows:
I have never heard of an adult male black widow being implicated in poisonous bites.  I assume that they are relatively safe.  The thing that makes the female's bite so dangerous is the great size of the poison glands which are not just confined to the chelicerae but extend back into the top of the head, allowing them to hold so much more venom.  I don't know at all about the size of the male's venom glands. 

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