322 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 3 



and ill normal conditions showed jinu-tically no difference in the mortality 

 resulting. 



The earliest weevil emerged on February 21; the last one on June 29, the 

 period of emergence covering 129 days. The earlier the weevils were confined 

 in the fall, the earlier the majority of them emerged in the spring. This 

 shows very clearly the value of early destruction of the stalks in the fall in 

 connection with poisoning with dry arsenate of lead as they are poisoned 

 much more easily in the spring. It is shown that weevils hibernating in 

 moss emerge much later than under natural conditions, 50 per cent emerg- 

 ing over a month later. 



The same is true of weevils hibernating in swamps and it is shown that 

 "the weevils hibernate in cool and shaded locations do not leave hibernation 

 till the summer heat has risen sufficiently for these places to be warm to the 

 temperature reached in the fields one to three weeks earlier." 



The average time the weevils lived in hibernation without food was 150.7 

 days. The weevil which lived the longest without food was placed in a cage 

 September 28 and emerged June 9, 255 days later. A detailed study of the 

 relation of the time of emergence from hibernation to the time when the 

 weevils were deprived of food in the fall, shows that when all cotton plants 

 are destroyed by October 1st the average weevil must live 183 days without 

 food before emerging from hibernation, but when the plants are left until De- 

 cember 21 the average weevil has but 94 days to remain without food before 

 leaving winter quarters. The average length of life of the weevils after leav- 

 ing hibernation was 10.7 days, the longest lived individual living 144 days. 

 The life of the weevils becomes shorter after leaving hibernation as the 

 weather becomes hotter. 



The weather conditions during the winter in which these investigations 

 were made are considered in detail and the authors conclude that "We 

 might therefore be justified in supposing that the normal .winter would be 

 survived by a slightly smaller percentage of the weevils, though an average 

 difference of 3.1° in temperature could hardly be expected to materially In- 

 crease the winter mortality among the insects," and "In the average season 

 the weevils would emerge from hibernation somewhat more quickly during 

 May than they did in this experiment. The winter was an exceptionally 

 dry one tho not far from normal so far as the temperature was concerned." 

 They conclude that the number of weevils living thru the winter of the ex- 

 periment was above the average, but that the rate of emergence from hiberna- 

 tion was normal. 



E. D. Sanderson. 



Lead Arsenate, by J. K. Haywood and C. C. McDonnell, U. S. 

 Dep't. Agric, Bur. of Chem., Bill. 131, p. 1-50, 1910. 



This interesting bulletin is in three parts. The first is on the results 

 of a chemical examination of the composition of lead arsenates found on 

 the market. Analyses of fifty different samples produced by fourteen 

 different firms are given. That the names of these firms are not given is 

 to be regretted, though the reasons for this are obvious, for anyone planning 

 to buy arsenate of lead would probably avoid purchasing of manufacturer 

 J. of the list, for example, if he could learn for whom J. stands. 



On the whole, the analyses show a considerable variation in the amount 

 of arsenic present and too much of it is in a soluble form, in many cases. 



