72 



These figures become exceedingly striking in consideration of the 

 fact that the cotton leaves were often purposely left until they became 

 moldy and decayed or dried and wholly unfit for food. It was at such 

 times that most of the weevils sought the sweet in preference. Should 

 we leave out of the account the weevils found at the molasses or sirup 

 when the cotton was unfit for food, the number attracted there would 

 be reduced fully one-half. In either case the fact remains that none of 

 the sweets can be said to have attracted weevils from the cotton leaves. 



INEL.XJENCE OF SWEETENED WATEit UPON EEEDnSTXJ OE WEEVILS 



ON COTTON PLANTS. 



It is easy to demonstrate that weevils will in confinement feed upon 

 sweet solutions. To prove that they will show the same attraction to 

 such solutions in the field is a far more difficult matter. 



For the purpose of these experiments, cheap molasses was used, 

 mixing 1 part of molasses with 25 parts of Avater, as is generally 

 recommended in spraying formulae. Three pairs of young plants 

 which had not begun to square were then selected from those growing 

 upon the laboratory grounds. The plants in each pair were of equal 

 size, and both in healthy condition and standing closely enough together 

 to be both covered by one cage. One plant of each pair was then 

 dipped in the sweetened water, while the other was left in its natural 

 condition. In each of the cages 10 weevils were then placed upon 

 the ground and midway between the bases of the plants. The object 

 of the test was to see which plant, the treated or untreated, would 

 attract the larger number of weevils. During the first three days 

 observations were made several times each day. Weevils found upon 

 either plant were counted at each observation. 



A summar}^ of the observations made on the first day before the 

 liquid had dried showed 15 weevils upon the sweetened plants and 16 

 on those not sweetened. These results were so remarkably even that 

 no attraction or repulsion could be ascribed to the liquid before it dried. 



During the ten days covered by the observations, however, 63 wee- 

 vils were found upon the unsweetened plants and only 45 upon those 

 sweetened. The weevils fed largely upon the petioles and somewhat 

 upon the blades of the leaves and the main stems of the plants. No 

 indication was observed of special feeding upon the ''gloss" left by 

 the drying of the sweetened water. In each cage the normal untreated 

 plant was destroyed before the treated one. During the first half of 

 the observations 52 weevils were found feeding upon the unsweetened 

 plants and only 32 upon the sweetened. Only after every leaf on the 

 untreated plants hung black and dead, while the sweetened plants 

 were in much better condition, did more weevils attack the sweetened 

 plants. 



