47 



In experiments 1 and 2 the American squares were attacked more 

 extensively than were the Egyptian, while in experiments 3 and 5 

 greater injury was done to the Egyptian. In experiment 4 the smaller 

 number of egg and feeding punctures made in the Egyptian squares is 

 counterbalanced by the larger number of squares attacked. Although 

 the totals from these five tests show slightly less injury to the Egyp- 

 tian than to the American squares, it could hardly be expected that 

 two arbitrarily chosen series, even if of the same variety, would show 

 any closer agreement in the points of comparison made in fchis table 

 than is therein shown by the American and Egyptian squares. 



HAS THE WEEVIL ANY OTHER FOOD PLANT THAN COTTON? 



The question* of the possibility of boll weevils feeding upon some 

 other plant than cotton is one of great importance. It is a well- 

 known fact that insects which have few food plants usually confine 

 their attacks to closely related plants belonging to the same botanical 

 family, or even genus. Accordingly, most of the plants which have 

 been tested especially are most closely related to cotton. Four species 

 of Hibiscus (H. esculentus, H. vesicarius, H. manihot, H. moscheutos) 

 were grown and an effort made to see whether weevils would feed 

 upon either the leaves, buds, or seed pods. In no case, however, did 

 they live on any of these for any considerable time, though they fed 

 slightly upon some of the parts. Hibernated weevils starved in an 

 average time of about 4 days with leaves of either okra or Sunset 

 Hibiscus. The buds and seed pods were not formed at that time, so 

 could not be tested. Weevils of the first generation, which had had 

 no cotton for food, were placed upon Sunset Hibiscus, and these 

 starved in an average of 3 or 4 days. First generation weevils, which 

 had fed for a few days on squares, were placed upon leaves, buds, 

 and seed pods of Hibiscus vesicarius. Though they fed a little, all 

 starved in an average of about 5 days. A lot of first generation 

 weevils, fed first for several days with squares, were given leaves, 

 buds, and seed pods of okra. More feeding was done by this lot than 

 by anj 7 other, all parts being slightly attacked. These weevils lived 

 for an average of 7 days. 



Numerous other plants, including sunflower (Helianthus annuus), 

 bindweed (Convolvulus repens), the slender pigweed and the spiny 

 pigweed (Amaranthus hybridus and A. spinosus), and western rag- 

 weed (Ambrosia psilostachy a), and various other species of weeds and 

 grasses which occur more or less frequently around cotton fields 

 were tested, but in no case was feeding noticed except in the case of 

 weevils supplied with pieces of the stem of sorghum, the stems of which 

 were cut into short lengths and some of the pieces split lengthwise. 

 Upon the exposed, juic} 7 pith weevils fed considerably, but they did 

 not puncture through the hard stem to obtain the juice. The sweet 



