Life Cycle Of Black Widows
The black widow spider is so named since the female eats up the male after mating. Approximately 11 percent males get eaten by the females post mating while many escape from becoming a prey. Males are consumed approximately a week after mating and not immediately after mating.
The males can mate almost three times or even more with one female after the other. The pheromones which are impregnated in the web of the female assists the male in identifying the female to mate with. Once identified, the male begins to cut and reconstruct the web in to sheets, strands and shapes of balls with the silken thread secreted for holding them together. During this period, the male keeps the female in a state of trance by vibrating his abdomen in a way so as to calm down the female. After about an hour’s time and completion of the weave, the male approaches the female in an attempt to mate. If he is repulsed, he will resume the cutting and rearranging routine and make two or more attempts for mating.
The female will be almost blind with this reconstruction while the male is well aware with it. Once the male feels that the female is ready, he will cautiously and continuously tap the female with his frontal legs and pedipalps. If not attacked, he will spin a weave around called the bridal veil in order to have a second to drop from the web if attacked at any stage hereon till mating. The male will insert its pedipalps and then introduce the sperm into the female. The male is considered to be in highest danger during insemination since it will take a little longer to withdraw and make a drop. Once the mating is complete or if the male is rejected many times by the female, it departs from the web in search of other females.
When located outdoors, the spider mates and spins its egg sacs in warm season. If located indoors, they will be able to mate and produce babies through out the year. In laboratory conditions, females were found to live for almost 3 years while males lived for a year.
The injected sperms will be stored in the spermatheca in the females. Once the eggs are available, the sperms will fertilize them and the fertilized eggs in the sacs will be spun in the silk cocoon. On an average a female can produce 5 to 10 sacs and each can house 150 to 250eggs. The eggs hatch in these sacs and disperse soon after hatching.
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The University of Tennessee Agricultural Extension Service: The Black Widow Spider