THE BOLL WORM REMEDIES. 379 



natingchrjsalids. Professor French has experimented upon thispoint, 

 and we quote his results from the Prairie Farmer for October 26, 1878 : 



To see what effect freezing would have upon the chrysaliUs under different circum- 

 stances I obtained quite a number the fore part of last December and treated them 

 as follows, numbering the different lots for convenience : No. 1 I put in loose dirt, 

 moistened a little and allowed to freeze ; No. 2 were put in loose dirt of the same 

 character, kept slightly moist, but were not allowed to freeze ; No. 3 were placed in 

 segments of the smooth cells or holes from which they hod been taken, the dirt of the 

 cells kept as moist as vrhen token from the field, but no loose dirt allowed to get into 

 the cells round the chyrsolids, and they were allowed to freeze ; No. 4, were treated in 

 the same way, but were not allowed to freeze ; No. 5, were cared for in a room of 

 about the iame temperature all winter and in a way best adapted to keep them from 

 moalding. 



After a few hard freezes, and the tempera.ture hod become milder, an examination 

 of lota 1 and 3, that hadbe-en allowed to freeze, showed that a.ll of lot one were dead, but 

 none of lot 3. Lots 2, 3, 4 and 5 were then placed side by side and cared for alike 

 the rest of the winter, go far as moisture and temperature were concerned, but after a 

 while those of lot 2 were taken out of the dirt and cared for the same as lot 5. These 

 began hatching May 27, of last spring, o.nd continued to come out till July 29, and 

 I could not see as any greater per cent, of lot 5, that had been well cared for all the 

 time, hatched, than 2 or 3. 



From the effect of freezing upon those that had been mixed with moist earth, the 

 conclusion was inevitable that fall plowing followed by fall rains and winter freezing 

 would produce the same result, for the plowing must break up their smooth cells and 

 allow them to become surrounded by the loose soil which when wet sticks to them. 

 If frozen in this condition they are evidently easily killed, but so long as their cells 

 remain entire no amount of freezing under ordinary circumstances seems to injure 

 them. 



This evidence seems very satisfactory, and in the northern part of the 

 cotton belt at least, as well as in the great corn-growing regions of the 

 West, fall plowing will undoubtedly prove an excellent remedy. In the 

 major part of the cotton belt, however, something else is needed. 



Destruction of the moths. — Lights and poisoned Sioeets. — These 

 remedies have been fully discussed under the head of Aletia, and the 

 reasons fcr their apparent want of success given. Testimony is not 

 wanting as to their efficacy with Heliothis. Mr. Schwarz, in one of his 

 letters from Texas, describes a simple trap-lantern used by planters in 

 the vicinity of Hearne, Tex., the use of which '^proved most effectual 

 against the ravages of the Boll Worm, which in 1877 did more harm here 

 than Aletia, and which was killed in great numbers by this method." 

 Experiments made by Mr. Schwarz during the summer of 1879 at Colum- 

 bus, Tex., where twenty lamps were watched and the captures tabulated, 

 showed that, although not so abundant, the moths of Heliothis were 

 more readily attracted by the lamps than Aletia, and more were caught 

 in this way. It must be remembered, however, in experiments of this 

 kind, that a large proportion of the moths captured are males, or females 

 which have already deposited their eggs. Mr. Crane, of Mandarin, Fla., 

 who lost in 1878 a large proportion of his crop of tomatoes by Helio- 

 this, in 1879 built fires of light wood in his field with much profit. 



