BLACK WIDOW SPIDER — D' AMOUR ET AL. 421 



drastic methods of eradication are employed, we will have a con- 

 siderable, and probably an increasing number of these unwelcome 

 guests. 



This leads to the problem of eradication. We have tested, under 

 laboratory conditions, several of the more common insecticides. The 

 general conclusion was that such insecticides as Flit and Black Flag, 

 in concentrations sufficient to kill promptly all flies within the room, 

 is without effect upon spiders, as would be expected from the difference 

 in the anatomy of the respiratory organs. Sulphur dioxide, in high 

 concentration, will kill them in time, as will carbon disulphide, though 

 relatively high concentrations and long exposures are necessary. 

 Often the spider appears to be dead and remains so for hours but 

 eventually recovers. Hydrogen cyanide, in the form of cyanogas, is 

 effective, but too dangerous to recommend for general use. The 

 California State Department of Health recommends the use of 

 creosote and crude oil sprays, which would no doubt be effective in 

 certain locations, but are obviously unavailable in vineyards or 

 tomato beds. The spider is far from gregarious in its habits and 

 consequently a given basement or garage will not harbor more than 

 perhaps a half dozen. Our suggestion, when called upon for advice, 

 has been to locate the individual spider, easiest done at night, and 

 destroy it, rather than resort to general fumigation. This advice is 

 valueless for the aforementioned farmer or fruit grower; protective 

 clothing during the picking season and burning of debris afterward is 

 about all that can be suggested. 



Does the spider represent a real menace? We have emphasized 

 throughout, in our dealings with the press and public, the fact that 

 the spider is above all extremely timid. We have rarely seen a spider, 

 disturbed in her web, who made any pretense of defense, to say noth- 

 ing of attacking. They will almost invariably run and hide and re- 

 main out of sight in a crevice or hole for hours afterward. The 

 danger lies in accidentally squeezing one when picking up some object 

 to which the spider is clinging, when putting on old clothing left 

 hanging in a shed, or in some similar way. Some children enjoy 

 catching and playing with crawling things, which cannot be done 

 with impunity with the black widow. As to the bite itself, there can 

 be no question of its frequently serious, sometimes fatal, effects. 

 The statement sometimes heard, even from zoologists who should 

 know better, that the bite of a black widow is no more dangerous than 

 that of a mosquito, must, in view of extensive clinical experience, be 

 branded as false and dangerous. 



There is, at present, no effective antidote. First-aid treatment 

 might well comprise the application of a tourniquet, free incision and 

 the sucking out of the venom either by means of the mouth or some 

 mechanical device. However, as Bogen has emphasized, the spider 



