16 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 



As partly illustrating this difficulty it will bo well to elaborate the 

 statcmeuts made in a paper read by the writer before the National 

 Academy of Science at its meeting in Washington in the spring of 1879. 



There are three principal theories on the subject that are wortliy of 

 consideration, and that are held by those with whom we have come in 

 contact, or with whom we have corresponded. These are: 



1st. That it hibernates in the chrysalis state. 



2d. That it hibernates as a moth. 



3d. That it does not hibernate in any part of onr cotton-growing 

 States, but comes into them on the wing from warmer climates where 

 the cotton-plant is perennial. 



Some few persons think that it winters in the egg state in cotton- 

 seed or on the dead stalk of the plant; but such views may be disposed 

 of by the statement that they are unsupported by even the appearance 

 of fact. 



At first blush it would seem easy enough to dispel whichever of these 

 theories is erroueuus and settle the question under consideration by a 

 few simple facts of observation. The trouble is, however, to get at the 

 facts. 



About one-fourth of the intelligent people of the South hold the opin- 

 ion that this Aletia hibernates in the chrysalis state, some believing that 

 it does so above ground, others that it retreats beneath the surface of 

 the ground. It has generally been stated by the writers on this insect 

 that the chrysalis could not endure the slightest frost. We have been 

 able to prove that it will suffer with impunity a temperature of from five 

 to ten degrees below the freezing point, but that it cannot withstand a 

 lower temperature; and all those chrysalides which do not give out the 

 moth before severe cold weather sets in perish beyond any doubt. ETow 

 easily men are misled even on this jjoint, however, may be gathered from 

 the fact that Dr. Anderson kept what he believed to be living specimens 

 nntil after the severe cold of December. A careful examination proved 

 that the lifelike motions of such chrysalides were due to the living pupa 

 which they contained of one of the parasites {Fimpla conqnisitor) pres- 

 ently to be described. The larger proportion of chrysalides that are 

 not empty after a severe frost has occurred are infested with some kind 

 of parasite, though many of them have perished from the effects of the 

 frost and are either rotten or moldy. 



Any number of intelligent planters insist that they plow up the 

 chrysalides in spring, and the belief that the last brood works beneath 

 the ground, out of reach of frost, is very firmly held by some of the 

 most experienced cotton growers; but in every instance that has come 

 to our knowledge the chrysalides thus ])lowed up have proved to be- 

 long to other species, most of them of the same family, and many of 

 them having a sufficiently close resemblance to those of Aletia to con- 

 found any but the most skilled and experienced entomologist. As an 

 illustration of the ease with which erroneous conclusions can be drawn 



