BLACK WIDOW SPIDER — D'AMOUR ET AL. 407 



(Dictionary of Latin Combining Forms Used in Zoological Names) 

 derives it from latro, Greek, a robber; and dect(o), Greek, to bite, biting, 

 a biter; hence, Latrodectus, a robber-biter. Mactans is a Latin word 

 meaning "murderous." 



DISTRIBUTION 



The most recent review of the distribution of the black widow which 

 has come to our attention is that of Burt (1935). This study, com- 

 bined with that of Bogen, leaves only the following States from 

 which the black widow has not been reported: Oregon, Minnesota, 

 Iowa, Missouri, Wisconsin, Illinois, and Vermont. It is almost cer- 

 tainly present in Oregon; in fact, very probably it will be found in 

 every State of the Union. According to Phillip (1935), Canadian 

 records are available for the Provinces of Alberta, British Columbia, 

 Manitoba, and Ontario, and southward its range in the mainland ex- 

 tends at least to Peru. The species has also been reported from 

 the West Indies. 



HABITAT 



The web of the black widow is an irregular structure, made of coarse, 

 elastic, tough silk. There is usually a central nest or pocket about the 

 size of one's finger to which the spider retreats when she is frightened, 

 and to which she carries many of her meals. The web is evidently 

 being constantly renewed and repaired, as the silk in an abandoned 

 web is dull in appearance, brittle, and weak, and easily distinguished 

 from the silk in an occupied web. The structure may be of no greater 

 extent than the mouth of a gopher hole, or as much as a yard each 

 way on the surface of a bank, probably being enlarged with the con- 

 stant renovation. Once the widow has established her web, she is 

 not likely to be found outside of it unless by accident or intent some 

 superior force drives her out. When this happens, she shows her dis- 

 comfort and fear by timid and awkward actions. With the onset of 

 cold weather, however, many reports have reached us of spiders 

 crawling about on walls and floors of dwellings. Apparently the cold 

 has driven them inside and they are hunting a more favorable winter 

 residence. 



The location of the web seems to be largely a matter of chance, 

 though in our locality some favorite sites are permanent holes or 

 fissures in a bank, such as the excavations made by swallows in a clay 

 bank; in brick, rock, or trash piles; in sheds, garages, outbuildings, and 

 basements; under loose rocks and in eroded holes in granite; in tile 

 roofs, etc. Webs and spiders have been found in abandoned birds' 

 nests in the pine trees of the foothills. Recently we found the whole 

 south side of a new country house in the suburbs of Denver harboring 

 young widows of this season in every possible retreat behind shutters, 



