ECONOMIC ZOOLOGY— ENTOMOLOGY. 



North American Phylloxerinee affecting- Hicoria and other trees, T. I'ki;- 

 gande ( Proc. Davenport Acad. Sci., 9 i 1901 1903), pp. 185 278, pis. ?1 ). The task of 



i lographing this group of plan! lice in America was begun many years ago with 



the intention of publishing the material in connection with a larger monograph 

 edited by Dr. Dreyfus of Wiesbaden, Germany. The publication of the large mono- 

 graph lias been so delayed that a decision was reached to publish the present material 

 separately. 



A synoptical table is given for the identification of the species according to the 

 character of the galls produced. All species of phylloxera known to occur in North 

 America are described and notes are given <»n their habits, life history, and food 

 plants. 



A treatise on spraying-, .1. M. Stedman (St. Joseph, Mo.: The Fruit Grower Co., 

 1905, />/>. 128, figs. 85). — This pamphlet is intended to furnish information regarding 

 the more important insecticides in common use, together with notes on methods of 



making and applying them and a brief discussion of the com n injurious insects 



which attack apple, peach, and strawberry. The remedies recommended and meth- 

 ods nf treatment suggested, however, are capable of wider application than to the 3 

 mentioned plants. 



Spraying tall trees, J. A. Pettigrew {Country ZAfe Amer., ? I 1905 |, No. '/. pp. 875, 

 .;;■:. figs. 8). — Attention is called to the injury done by San Jose scale and other 

 insects to tall shade and ornamental trees, and various power sprayers especially 

 suitable for treating such trees are described. 



Composition, of the lime, sulphur, and salt wash, J. K. Haywood {Jour. Amer. 

 Chem. Soc, 27 ( 1905), No. 3, pp. 244-255). — A study was made of this wash, adopt- 

 ing different periods of boiling and using chemically pure reagents for the tests. 



Careful analyses were made for the purpose of determining the reactions which 

 take place during the manufacture of the wash. It was found that the solid sulphur 

 was not completely dissolved during a boiling period of 15 to :>() minutes, but only 

 after boiling from 45 to 60 minutes. When the boiling was continued beyond the 

 hour the mixture became thick, and apparently some of the sulphur was lost 

 mechanically. Omitting the salt ''had no material effect on the composition of the 

 wash." 



In the study of the compounds of sulphur formed in the wash under different con- 

 ditions, the free sulphur and that as sulphids, as sulphates and sulphites, and as 

 thiosulphates were determined. Concerning the reaction which takes place, the 

 following conclusions are reached: "First, the lime and sulphur react and calcium 

 thiosulphate and pentasulphid are formed; second, the calcium pentasulphid is 

 partly changed to calcium thiosulphate and free sulphur; third, the sulphur set free 

 recombines to a large extent with the calcium hydroxid; fourth, the calcium thio- 

 sulphate formed is changed to a slight extent to calcium sulphite and sulphur; fifth, 

 the calcium sulphite is partly oxidized to calcium sulphate. All of the above reac- 

 tions are well known and can he found in the leading hooks of reference." 



The changes which take place in the sulphur compounds when the wash is sprayed 

 upon the tree were studied by applying the wash to filter paper and exposing it to 

 the air. Later, after several days or weeks, the dried wash was analyzed, and the 

 results are presented, showing the amounts of sulphur in different forms. There 

 was found to he a decomposition of the thiosulphate after a time, resulting in an 

 increase of free sulphur, sulphates, and sulphites, and it is assumed that after } or 5 

 months only sulphur and calcium sulphate would remain. This finely divided sul- 

 phur and the sulphite which is gradually set free, tin' author believes to he the two 

 active agents in killing insects. "This theory of the action of the wash would also 

 explain why the action is not immediate and also why it continues over a great 

 length of time." 



4393— No. 1—05 5 



