HISTOEY OF EAVAGES, 1645. 23 



the crop at least in this region lias been destroyed, how much more time will deter- 

 mine. With the overflow and now the army-worm, the planter has but a slender 

 prospect of being remunerated for his labor. 



The Alexandria Republican for August 31, 1844, has the following : 



A visit to Bayou Eeef has given us ocular proof of the fearful ravages of the dreaded 

 caterpillar. The work of destruction has been complete. Scarcely a green leaf is to be 

 seen in any direction the plantations resembling rye-fields. In the opinion of the 

 best informed, the yield in the parish will not be more than one-third of the average 

 crop. Bad news, but true. 



In other cotton States the destruction was not to be compared to this, 

 in spite of the newspaper exaggeration which marks it. In Mississippi 

 the damage was slight. In Alabama, certain localities report consider- 

 able injury. In Monroe County the worms were " bad in sections." In 

 Clarke County they were very destructive. In Greene County the loss 

 amounted to 33 per cent. In Georgia and Florida the loss was very 

 slight. 



In 1845, the damage was greater than it had been since 1838. A 

 curious instance is mentioned of this year by Mr. E. Richards,* of Cedar 

 Key, Ma., showing the migratory power of the moth : 



The last of July, 1845, these caterpillars made their appearance in a small field of 

 tliree or four acres of sea-island cotton, planted on Way Key, as an experiment to see 

 if cotton could be advantageously cultivated on the Keys, no other cottou having 

 been previously planted within 80 miles of them; but the whole crop was devoured. 

 The caterpillar was at the same time destroying the cotton in the interior of the 

 country. 



Mr. Glover remarked concerning this statement 



It would seem to prove that it (the cotton-moth) is migratory in its habits, as there 

 is no other way of accounting for its sudden presence, except that, having previously 

 existed on some other plant or weed, it had left it for food more congenial to its taste, 

 although it has been asserted that the real caterpillar will eat nothing but cotton. 



This being the year preceding the graat cotton-worm year of 1846, it 

 is worth our while to look at it more carefully than at others. It is at 

 the head of an ascending scale of years, beginning with 1839. Eacli year, 

 from 1839 to 1845, the destructions were gradually increased. As more 

 moths hibernated, the more caterpillars there were the ensuing year. 

 Throwing parasitic and climatic checks aside, the tendency would be 

 for the worms to increase in geometrical proportion. As the caterpillar 

 increased, however, so, naturally, will the parasites ; and when once, 

 through meteorological reasons, the cotton-worms receive a decided 

 check, the parasites will be in a position to reduce their numbers to a 

 marked degree. This being the case, we would expect to see, in a suc- 

 cession of favorable years, a gradual increase in the ravages of the 

 caterpillars, until, after a year of great injury, there is a sudden falling 

 off a drop, as it were to the bottom of another ascending scale of 

 years. This succession will, of course, be modified by many circum- 

 stances, but the tendency will always be the same. 



The year 1846 was the third of the twenty-one-year irruptions, and 

 * Dept. of Agr. , Eept. 1855, p. 74. 



