Insect and Spider Identification: Is this a black widow???, 1 by bokisan

bokisan wrote:
that is definitely a female black widow spider, Latrodectus mactans

the degree of black on their bodies depends upon how many times they have molted.

they begin with the same colouring as males,
overall olive colour with complex red and cream pattern underneath,
also red and cream stripes on the back. the pattern is typically, one stripe down
the middle of the back, and then a set of parallel stripes from it, angling downward and backward.
these stripes have a red core, surrounded by cream.

through successive instars, the females' olive/amber background colour quickly turns black, and the cream disappears, then, gradually the red. the last remaining red on an adult female is the red hourglass on the belly.
then, further instars result in the splitting of the hourglass into to red marks, then onwards to no red at all, if she lives long enough.

the males never lose their juvenile colouration through their entire life.

the reason her abdomen looks weird, is that it is shriveled.
she just hasn't eaten in a long time, and if she is stressed, and doesn't eat soon, she will perish.
if the jar remains unmoved overnight, and she hasn't built some sort of confused web,
she is doomed. if she hasn't built a confused, but clean, web with taught strands within a couple days of the jar not having been disturbed, better to put her out of her misery.

if she does set web, put a small bug in for her, to revive her.
a fly, a bee, or small cricket are best.

when a female is eating regularly, her abdomen inflates like a balloon.

the real give-away between males, and juvenile females, is the appearance of their pedipalps, or "feelers", at their mouth.
males have bulbous ones, because that's their sex organ.
females have tiny ones, like little feeler legs, tiny and slim, no bulk, no matter how big she is.

i just published this time-lapse video yesterday, of an adult male being placed on a new structure, free of web.
in this first hour+ on the structure surrounded by a moat, you can see that he checks out the extent of his new world,
sets down some basic strands that he can then navigate with, and then sets up at the high point and chills

i believe he is Latrodectus hesperus, but his colouration is typical of males, and of juvenile females of the mactans species, as well.
when you see a female she may look like this, or like any one of the stages in the sequence of her losing her colour and becoming all black, so that is what you are looking for, ... something anywhere from this, to jet black high gloss.

i have been keeping, and raising black widow spiders, off and on, since 1976

video here
http://www.youtube.com/watch?v=je96UIquQ8g

This message was edited Sep 22, 2011 6:33 AM