245 



because of insect pests, when organised remedial measures would 

 render them profitable. Railroad co-operation with government or 

 other agencies would often be beneficial, while in matters of cpiaran- 

 tine and inspection an entomologist would eliminate a great deal of 

 loss and friction. 



Pierce (W. D.). Commercial and Professional Entomology — the 

 Future of our Profession. — Jl. Econ. Enfoni., Concord, N.H.. xiii,^ 

 no. 1, February 1920, pp. 117-123. [Received 13th April 1920.] 



The sphere of activity of an entomologist working independently as 

 a professional and con-;ulting specialist is discussed. Of late years 

 business men recognise the possibilities of scientific processes, and brains, 

 foresight and initiative can name their price. A combination of inves- 

 tigation, consultation, demonstration, practice and possibly manufac- 

 ture offers the widest scope. Results must be produced cpiickly. An 

 entomologist must know how to present estimates of the cost of his 

 work, and how to keep the cost at a competitive level. 



Newell (W.) & Bynum (E. K.). Notes on Poisoning the Boll Weevil. 

 Results of an Investigation to Determine whether the Presence of 

 Dew or Rain Water on Cotton Plants is necessary to the effective 

 use of Arsenates. — Jl. Econ. En'om., Concord, N.H., xiii, no. 1, 

 February 1920, pp. 123-13G, 1 plate. [Received 13th April 1920.] 



The experiments here described were made in field-cages, the cotton 

 plants being treated with either calcium arsenate or lead arsenate or 

 left untreated as a control, some cages in each class being protected 

 from all rain and dew. Further experiments were made to find the 

 amount of poison in the dew on treated plants, and the eft'ect of this 

 dew on the weevils [An'honomus grandis] when deprived of other 

 food, and also when supplied with unpoisoned food and poisoned dew. 



These showed that the mortality among boll-weevils on cotton 

 plants treated with lead and calcium arsenates and kej^t 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 efiectiveness of either lead or calcium arsenate as a boll- 

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

 these 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 lb. per acre was found, upon analysis, to 

 contain 6'7 parts of arsenic per million. Dcav from plants treated 

 with calcium arsenate at the same rate was found to contain from 10 

 to 43"5 parts of arse;iic per million. The dew was collected only from 

 cotton leaves that showed a distinct, thorough white coating of the 

 arsenates. 



Boll- weevils deprived of all food and having dew from treated plants 

 as the only source of moisture su tiered a greater mortality than boll- 

 weevils confined with clear water, showing that the dew contained 

 sufiicicnt arsenic to produce death when the weevils were compelled 



