125 



tlie boll- worm, [ReUothis armigera,) aud some iujury iu localities by the 

 tlie cotton-louse, or Aphis. 



The theory of our entomologist, which he deems to be sufficiently 

 verified by some years of study in the field, as to the movement and 

 spread of the caterpillar is, that iu the more northern portion of the 

 cotton-belt the frosts of winter destroy the insect in all its stages, unless 

 in situations of unusual protection, but that in the more southern por- 

 tion, where severe frosts rarely occur, they survive the risks of winter, 

 and as they increase, by their repeated generations during the summer, 

 they migrate northward in the fly-state (the perfect insect) to " fresh 

 fields and pastures new." This would account for the general preva- 

 lence of the insect on the Gulf coast, and its comparative scarcity and 

 late appearance in more northern regions, which facts are by no means 

 singular in the records of the past year, but in accordance with the his- 

 tory of former vi.sitatious. Their first appearance in Florida was noted 

 in June, while in North Carolina they generally came too late to do 

 much injury; indeed, their presence is rather desired in September by 

 many northern cultivators, that the leaves may be partially stripped 

 and the growth of weed checked for the better maturing bolls before 

 the coming of October frosts. Very few of the Tennessee counties re- 

 port injuries b}' cotton- worms, and those are either in the first or second 

 tier of counties from the southern line, and in no case is the injury re- 

 ported of any great severity. In Georgia several southwest counties 

 reported the presence of worms in June, as Stewart, Schley, and Sum- 

 ter ; in July the counties infested were farther north, but considerably 

 scattered. A similar state of facts is presented in returns from other 

 States, sufficient to show that their earliness of appearance, aud there- 

 fore serious multiplication in subsequent months, bears a marked rela- 

 tion to the degree of winter temperature of different cotton-growing 

 districts. Still, it is impossible to trace closely everj' step in their pro- 

 gress northward, from the tact that the caterpillar and boll- worm are 

 not generally distinguished in the reports, but are usually included 

 under the term " worms.'' 



These returns also include a record of the time of commencing the 

 first picking, a statement of the average date for a series of years, the 

 date of recurrence of the first killing frost, and the average date of the 

 first destructive frosts. The statements of the different counties of 

 each State, so far as reported, are recorded and an average made, which 

 is presented in the following table: 



These figures indicate about an average forwardness of the plant in 

 Georgia, with a constantly increasing retardation* westward, from Ala- 

 bama to Texas, though singularly enough the date of the five States 

 differs only by a single day, all but Texas and Alabama having the 



