The black widow spider

A female black widow spider photographed from above.

The moment I saw it, I knew it was a black widow spider, and a female with eggs to boot.  She was suspended upside down between two concrete blocks on her web of death, the ample bodies of her victims strewn beneath her.  I uncovered this deadly arachnid as I was tidying up an area; as I removed some overburden she was exposed.  The red hourglass mark (see inset) on her abdomen gave her identity away.

Although lethal in a larger dose, black widows are not normally able to kill a human.  Their venom is about 15 times more potent than a rattlesnake's, but the amount they can inject in a single bite is relatively minute.  The poison is alpha-latrotoxin and acts by altering the permeability of neurons to cations causing extreme pain.  In large doses it causes lysis of cell membranes and will result in death; fortunately, that rarely happens.  Of the 1015 people bitten by black widows in 2018, none died from the attack.

Male black widows look considerably different from their female counterparts and are not themselves equipped with such potent venom.  While females tend to remain in a single area, males wander about in search of a potential mate.  They are much smaller than the large females and are easily overpowered by them.  The black widow gets the name honestly; males are often devoured after their part of courtship has been completed.  Apparently, the wanderlust associated with the desire to mate can be fatal.  I wonder if the same holds true for us.

Thanks for reading.

Eric Svendsen     www.ericspix.com