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we are acquainted. On the years of its appearance, the entire 

 cotton crop of certain districts is often cut short ; and in not a 

 few instances, single plantations have suffered to the amount of 

 from ten to fifteen thousand dollars. 



It is one of the span-worms or GeometridcB^ belonging to the 

 same family of insects as the canker-worm, which is so much 

 feared by horticulturists of the north. 



I have as yet only seen the larva. It is not indigenous to the 

 Southern States, and there is no evidence that it can live natu- 

 rally north of the shores of Texas. Most probably it is a native 

 of Brazil or some other equatorial climate in that vicinity ; for it 

 is so sensitive to the cold, as to quickly die in an atmosphere 

 even approaching the freezing point. It appears, then, on the 

 Southern cotton fields, always as in migration, coming suddenly 

 like a foreign enemy, and always selecting the most thrifty 

 plantations. It is very remarkable, therefore, that it should 

 appear regularly at intervals of every three years in the same 

 districts, striking first the seaboard and progressing gradually 

 inland as circumstances may favor. But equally remarkable in 

 this connection is the fact, that its most extensive and deplorable 

 ravages occur always after intervals of twenty-one years, or 

 every seventh time of its advent, as shown in the years 1804, 

 1825, and 1846, during the last half century. These facts are 

 inexplicable, unless referable to some peculiar conditions of their 

 economy in their native land. Little is known from what south- 

 ern direction they come ; for, like all insects of this family, their 

 movements are made at night, and the seaboard planter often 

 rises in the morning to find whole sections of his plantations 

 covered with the adult insects busily engaged in depositing their 

 eggs on the tender leaves of the cotton. There is, however, no 

 regularity in the exact month of their coming, for Mr. Chisolm 

 says that on his plantations they came in 1840 quite early, but in 

 1843 much later, and remained until frost ; in 1846, in June, and 

 in 1849 and 1852 in August. 



The cotton-caterpillar is nearly always accompanied directly 

 by another insect called the Boll-worm (probably one of the 

 Noctuidcp) which confines its attacks to the immature lint and 

 seeds of the green pods of the short-stapled variety of cotton ; 

 and, as short cotton is mostly cultivated in sections farther south 

 than those of the long-stapled variety, this boll-worm is generally 



