244 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 4 



of 3'ears. The last thoroughly wet summer here was in 1891. During 

 the cooler months, from June to October, there is considerable moisture 

 in the air, especially during the night and the early forenoon. The 

 weevil can flourish here only during the cooler weather, its greatest 

 influence on the crop* being visible in July and August. Cold, \vith 

 humidity, is thus seen to be the indirect cause of the damage, in so 

 far as it allows the weevil to become and remain active. 



It was noted in Piura Department that the season following the 

 wet summer of 1891 showed a practical absence of hielo symptoms, 

 the heavy floods having probablj^ destroyed the major part of the 

 weevils in the cotton districts. 



It should be noted here that I have not as yet found the weevil 

 attacking the l)olls to any extent whatever. So far as I have been 

 able to ascertain, its injury is confined to the squares, and the term 

 square-weevil therefore seems fitting. But it must be stated that 

 cotton grows and produces squares the year round in this country, 

 and it is highly probable that in the absence of squares this weevil 

 would attack the bolls in much the same manner as the boll-weevil. 



Since the present species is so closely similar to the boll-weevil in 

 general form and appearance, if not in structure, and has practically 

 identical habits, it may be seen that its investigation throws important 

 light on the boll-weevil problem in North America. While the boll- 

 weevil has spread northward through Mexico into Texas, and east- 

 ward into the humid cotton area of the Southern States, it has been 

 noted with surprise that it has never become established in the exten- 

 sive cotton growing region of Mexico known as the Laguna District. 

 The latter is extremely hot and dry, lying as it does in a low basin of 

 the plateau region. On a trip which the writer made to Yucatan in 

 May, 1896, only one specimen of the boll- weevil could be found. 

 May is the height of the dry season in Yucatan, and the weather was 

 extremelj^ hot. The boll-weevil is much less serious in the central 

 and western parts of Texas than in eastern Texas and Louisiana. The 

 former are very dry and hot as compared with the latter. It has been 

 noted that since the boll-weevil entered the humid part of the cotton 

 belt its progress has been much more rapid and its damage more 

 serious. It has long been recognized that heat and drought are the 

 most potent factors in the natural control of the boll-weevil, but we 

 were not at first prepared to accept them as an actual barrier against 

 its spread. Such, however, seems to be very largely the case. Com- 

 paring the facts in both cases, it becomes evident that the boll-weevil 

 of North America and the square-weevil of South America are alike 

 in their inability to withstand great heat and drought. 



It may be inferred as extremely probably that Anthonomus is a 



