Western Black Widow

(Latrodectus Hesperus)

black widow

 

Latrodectus hesperus, the  western  black widow spider  or  western widow, is a venomous spider species found in western regions of  North America. The female’s body is 14–16  mm (1/2 in) in length and is black, often with an  hourglass-shaped red mark on the lower abdomen. This “hourglass” mark can be yellow, and on rare occasions, white. The male of the species is around half this length and generally a tan color with lighter striping on the abdomen. The population was previously described as a subspecies of  Latrodectus mactans  and it is closely related to the northern species  Latrodectus variolus. The species, as with others of the genus, build irregular or “messy” webs: Unlike the spiral webs or the tunnel-shaped webs of other spiders, the strands of a  Latrodectus  web have no apparent organization. Female black widows have potent venom composed of neurotoxins. Fatalities usually only happen with children and the elderly, however medical treatment may be required for others as well. However, the male black widow is harmless to humans. The female’s consumption of the male after courtship, acannibalistic  and suicidal behaviour observed in  Latrodectus hasseltii  (Australia’s redback),[3]  is rare in this species. Male western widows may breed several times during their relatively short lifespans.[4]  Males are known to show preference for mating with well-fed females over starved ones, taking cues from the females’ webs.[5]

Taxonomy/Etymology Latrodectus Hesperus also known as black widow or western black widow.

 

Info By http://en.wikipedia.org/wiki/Latrodectus_hesperus

Pic By cisr.ucr.edu