Black Widow Eggs Sac | Spider Baby Size

Black Widow Eggs Sac | Spider Baby Size

Latrodectus genus broadly distributed genus and contains lots of species & few are common. Black Widow Spider commonly known due to fact that female spider kill and also eat male spider after mating. Know about Black Widow Spider Egg sac, baby and size details. Black Widow known as most venomous spider in the world. Also venom of Latrodectus spider species 15 times strong than rattlesnake.

Common Species

  • Latrodectus mactans (Southern Black Widow)
  • Latrodectus hesperus (Western Black Widow)
  • Also Latrodectus variolus (Northern Black Widow)
  • Red Widow Spider (L.bishopi)
  • Brown Widow Spider (L. geometricus)

Black Widow Eggs

Widow spider life cycle – Black widow mating occur in springtime into early summer. In few cases female widow spider eat male after mating, feeding on them as nutrient source for egg fertilization. They produce egg sac in summer season. Black Widow egg sac – Sacs are as silken cups, tightly woven and protected until spiderlings comes out.

Egg sac color – white, gray or tan color and paper like texture.

Black Widow Eggs Sac
Black Widow Eggs Sac

Black Widow Egg size РEgg case 12 to 15 mm in diameter. Shape Рpear shape or globular and contain hundred of eggs. Only few spiderlings survive (due to black widow are cannibalistic during early stage).

After that surviving Black Widow Babies undergo developmental stage including various instars. Babies are orange to white in color and as same as mature spider males. Female get black color as they grow older. Hatched spiderlings leave web within couple of days and begin to spin own web and capture their own food.

Lifespan of black widows is about one year and some species live upto three years. These spiders live long in captivity.

Black Widow Spider Eggs

Latrodectus mactans (considered as original black widow) – Southern Black Widow egg sac brown, papery and about half inch long. Also shape varies oval to pear shape. They hold 25 to 900 or more eggs. incubation period of 20 days and growth period 60-90 days. Older females dying in autumn after egg laying.

Latrodectus hesperus – Western Black Widow Egg sac – Free hanging – tear drop to spherical in shape. Color – Light yellow to tan color, margin distinct. Covering very tough silk covering (paper like texture). Number of eggs per sac – 160 to 225 and a female spider can produce min 14 sac in a summer season.

Latrodectus variolus – Northern Black Widow Egg Sac – Egg sac commonly white, tan or grayish in color. Shape – spherical or pear shaped object hung in female’s web. It contain 100 to 400 eggs. Incubation period – about one month as incubation.

Widow spider babies are known as cannibalistic and few survive. Also it take up to three months to develop from juvenile to adulthood.

Black Widow Spider Baby

Brown Widow Spider Egg sac – Latrodectus geometricus egg sack about one centimeter in diameter. New Brown Widow sac white but become yellow or tan with age. After hatching of young, egg case turn dark gray because mass juvenile show through walls. It’s sac unique because of white silk spikes on surface unlike others. Egg sac diameter – 1 cm and egg diameter 0.1 mm.

Red Widow Spider Egg Sac – Latrodectus bishopi has red to orange cephalothorax and black abdomen. It does not have familier hourglass.

Read more about – Brown Widow Spider Poison

Overview – Black Widow Spider egg sac contain as many as 400 eggs in a single case and produce several egg case in summer season. After black widow spider hatch, babies begin to change color. Time taken depends on conditions like temperature and when babies come out. Babies goes through lots of phases called molting. On average basis only 30 of babies survive after initial molting.

Black Widow Spiderlings take 60 to 90 days to mature. They can breed after 6 to 9 months (when fully mature). No parental care for newborn babies. Male black widow have shorter lifespan as compare to female.

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