42 REPORT UPON COTTON INSECTS. 



paper, Mr. Townend Glover was casually placed on record * as favor- 

 ing what may be called & partial iitun it/ration theory, in the, following 

 words : 



The theory of oar 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 iu situations of unusual protection, but that ui the more southern 

 portion, where severe frosts rarely occur, they survive the risks of Avinter, and us they 

 increase, by their repeated generations during the summer, they migrate northward 

 *a the fly-state (the perfect insect) to "fresh fields and pastures new." This would 

 account for the general prevalence of the insecton the gulf coast and its comparative 

 scarcity and late appearance in the more northern regions, which facts are by no 

 means singular in the records of the past year, but in accordance with the history of 

 former visitations. 



All credit should be given to Mr. Glover for this phase of the theory, 

 which the extended investigations of the past year show to have been 

 more nearly correct than any suggestion heretofore made. Indeed, the 

 work of Mr. Glover on cotton insects, the results of which are scattered 

 all through the Department of Agriculture reports from 1854 to 1874, is 

 by far the most valuable that has been done by any one person. This 

 tribute is due to Mr. Glover, and we can only regret that a painful dis- 

 ease debars him from prolonged scientific work. 



In 1875, instead of an increase over the preceding year, we see a still 

 further decrease in the prevalence of the cotton caterpillars, owing to 

 nearly the same causes which produced the decrease iu 1874. Eighteen 

 hundred and seventy-five was another very dry year, and in August and 

 September there was an occasional severe storm, causing great damage- 

 From these causes the caterpillars were so held in check that in the 

 monthly report for September, 1875, we find the following statement : 

 "Losses from prevalence of insects will scarcely be a factor in calculat- 

 ing the product of the present year." In fact, the only State in wliich 

 much damage was done was Florida. In Texas they were first seen in 

 July, but in very small numbers. In Austin County alone do they ap- 

 pear to have done any material damage, unless we except Polk County, 

 where the crop is said to have been " partially destroyed." Slight in- 

 juries were reported from Matagorda, Fayette, Waller, Hardin, Walker, 

 Limestone, Bosque, and Upshur. From Louisiana there were no reports 

 of insect prevalence in 1875. The cotton- worm was there, but in such 

 small numbers that it would have been a waste of ink on the part of 

 correspondents to mention it. From Arkansas the caterpillars were re- 

 ported from Woodruff and Pope Counties. In Mississippi the damage 

 was very slight. In Alabama the worms were more abundant than in 

 the last-named States, but still did but little injury to the crop. In 

 Lowndes they were reported to have eaten things clear, but in other lo- 

 calities they were not worthy of extended notice. In Florida the damage 

 was greater. The caterpillars do not seem to have been noticed early in 



Department of Agriculture, monthly Report, February :md March, 1*74. 1 



