162 EXPERIMENT STATION RECORD. [Vol.43 



The European corn borer problem, E. P. Fklt (Jour. Econ. Ent., 13 (1920), 

 No. 1, pp. 59-91). — This is a general exposition of the European corn borer 

 problem, followed by a discussion of the subject by C. L. Marlatt (pp. 73-86) 

 and others. 



The mosquito must go, T. J. Headlee and M. Cabboll {New Jersey Stas. 

 Circ. Ill (1919), pp. S-j^Jf, figs. 11). — This is a discussion of the mosquito prob- 

 lem in New Jersey, in which the results already obtained are reviewed and the 

 work still to be accomplished is set forth. The benefits obtained from mosquito 

 elimination are emphasized, and correspondence relating to the subject is 

 appended. 



State laws concerning nu)squito control work in New Jersey (New Jersey 

 Stas. Circ. 110 (1919), pp. 8). — The texts of the laws relating to mosquito con- 

 trol in New Jersey are here brought together. 



Anopheles quadrimaculatus and A. ijunctipennis in salt water, F. E. 

 Chidester (Science, n. ser., 51 (1920), No. ISlIf, pp. 2^, 2Jf5). — The author 

 records the rearing of several adults of A. quadrimaciilattis and A. punctipetmis 

 from larvfe taken in brackish water. 



Notes on poisoning the boll weevil, W. TVewell and E. K. Bynum (Jour. 

 Econ. Ent., 13 (1920), No. 1, pp. 123-136, pi. 1, figs. 5).— This is a report of an 

 investigation made to determine whether the presence of dew or rain water 

 on cotton plants is necessary to the effective use of arsenates. The results 

 have been sunmiarized as follows : 



" The mortality among boll weevils on cotton plants treated with lead and 

 calcium arsenates and kept protected from all rain and dew was appreciably 

 higher than the mortality on plants similarly treated but exposed to dew and 

 normal precipitation. As the presence of dew or rain water on the cotton 

 plants does not increase the effectiveness of either lead or calcium arsenate as 

 a boll weevil poison, it is evident that mortality from the use of either poisons 

 is brought about by ingestion of the poison with the weevil's food and not 

 by drinking the so-called ' poisoned dew.' 



" Dew collected from cotton plants treated with lead arsenate at the rate 

 of approximately 8 lbs. per acre was found, upon analysis, to contain 6.7 parts 

 of arsenic per million. Dew from plants treated with calcium arsenate at the 

 same rate was found to contain from 10 to 43.5 parts of arsenic per million. 

 The dew was collected only from cotton leaves that showed a distinct, 

 thorough white coating of the arsenates. 



" Boll weevil deprived of all food and having dew from treated plants as 

 the only source of moisture suffered a greater mortality than boll weevils 

 confined on clear water, showing that the dew contained sufficient arsenic to 

 produce death when the weevils were compelled to take the dew and no other 

 food or water over a period of several days. However, such a condition does 

 not occur in cotton fields. When boll weevils had access to food in the form 

 of nonpoisoned cotton squares and, at the same time, to dew from treated 

 plants, no mortality resulted, showing that the weevil can be poisoned under 

 normal conditions only by poisoning its food." 



The following conclusions have been drawn : " As the boll weevil is poisoned 

 largely or entirely through taking poison with its food, machinery for applying 

 the poison to the cotton plants should be so designed as to apply the poison 

 primarily to the squares, , bolls, and terminal buds, rather than to the foliage. 

 The greatest mortality among the boll weevils occurred on the third day fol- 

 lowing application of the arsenates and fell off rapidly after the seventh day, 

 indicating that, other things being equal, application should be at intervals of 

 a week, or less, apart." 



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