420 ANNUAL. REPORT SMITHSONIAN INSTITUTION, 19 3 8 



its habits, that is, is it leaving its rural haunts and invading settled 

 communities to a greater degree than before? 3. What methods of 

 eradication are feasible? 4. Does the spider represent a real menace? 

 5. Is there any effective antidote? 6. What are the possibilities of 

 antivenin? To the first question the authors do not hesitate to give 

 an affirmative answer. This may appear unjustified since this is 

 admittedly the first year in which we have collected the spider. If 

 the black widow were smaller, if its appearance were not so striking, 

 if it were easily confused with some other form, or if it had previously 

 been fairly common, one might hesitate to commit himself. How- 

 ever, as an example, we have a cold box set just outside the labora- 

 tory, on the ground level, and opening into the room by means of a 

 window. So far, we have on two different occasions found three 

 spiders at one time and another time two spiders, in webs close to 

 the window. They are visible all the way across the room. When 

 opening the window, one must be blind not to see them. This box 

 has been there for years. We feel morally certain that had spiders 

 ever been in the same location before we would have Eoticed them. 



It is, of course, true that one sees what one looks for, and the 

 newspaper publicity which these spiders have received has caused 

 many more of them to be noticed and reported than would otherwise 

 have been the case. On the other hand, farmers and fruit growers 

 are usually quite observant as to the kind of insects found on their 

 crops and when this year, for the first time, reports are received 

 that tomato growers find the spiders so bad that protective clothing 

 must be worn, when grape growers report that in some places the 

 spiders are so numerous that the pickers refuse to work and the 

 grapes are rotting upon the vines, and peach growers notice many of 

 them in their orchards, the conclusion seems inescapable that they 

 are more numerous this year than ever before. 



The second question, relating to an apparent change in the habits 

 of the spider, in that it seems to be invading settled communities to 

 a greater degree, is to some extent dependent upon the first. If the 

 spiders in a given region increase greatly in numbers, their manner of 

 dispersal by wind and their utilization of such means of transporta- 

 tion as box cars would make it inevitable that some would find them- 

 selves within towns and cities. Once having become established, 

 their chances for survival and increase are favored. Many of them 

 have been found in basements, garages and similar places where they 

 are protected against the cold to a much greater degree than would 

 be the case out in the open. We believe that the increase in num- 

 bers noted during the past summer is due to the mild winter which 

 preceded it; however, cold will not operate as a check upon those 

 which have established themselves in the garages and basements of 

 heated buildings. The conclusion appears inescapable that, unless 



