240 THE CANADIAN ENTOMOLOGIST 



BOOK REVIEW. 

 The Use of Carbon Bisulphide Against the White Grub. By W. H. W. 

 Komp. Soil Science, Vol. X, No. 1, pp. 15-28. Miscellaneous Soil In- 

 secticide Tests by J. J. Davis, Soil Science, Vol. X, No. 1, pp. 61-72, pis. 

 1, 2, 1920. 



The above two papers, which are of entomological interest, have recently 

 appeared in Soil Science, a journal devoted to soil physics, soil chemistry and 

 soil biology. While they are clearly within the field of soil biology, it is doubtful 

 if they will reach the eys of many entomological readers and, for such a reason, 

 it was thought advisable to prepare this brief notice. Mr. Komp's paper deals 

 With the determinations of the maximum dosage of carbon bisulphide non- 

 injurious to such plants as blue-grass and clover, the minimum dosage fatal to 

 the grub, and the influence of temperature and moisture conditions upon the 

 effectiveness of the fumigation. Presumably, Lachnosterna larvae were used. 

 A detailed account of the experiments is given together with tables showing 

 air and soil temperatures, dosages,- effect of carbon bisulphide on plants and 

 percentages of grub mortality, using different, dosages at different depths and 

 distances in the soil. Mr, Komp concludes that the maximum dosage for 

 ordinary lawn and golf-grasses appears to He somewhere between 1 and 5 ounces 

 per square foot and considerably above the former, while the minimum dosage 

 for the white grub is about 1 ounce, also that temperature exerts a decided 

 influence on the minimum dosage for the white grub (1 oz. at 65 degrees F. and 

 less than 1 oz. at 85 degrees or above). The injections should not be much over 

 six inches apart. The soil moisture must be medium (10%) to wet (20%) for 

 good results. In addition the charge of carbon bisulphide should be placed 

 several inches below the point where the grubs are working. A limiting factor 

 in the use of carbon bisulphide against the white grub in situations in which 

 it cannot be reached by cultural methods is its relatively high cost. According 

 to the tables in Mr. Komp's paper, the number of larvae used in a single experi- 

 ment varied from 2 to 4, and the mortality figures or percentages are based on 

 these numbers. These appear to be far too small to insure any degree of cer- 

 tainty in the results. 



The second paper by Mr. Davis reviews briefly the results obtained by 

 various workers using such soil insecticides as carbon bisulphide, sodium cyanide, 

 potassium cyanide, hydrocyanic acid, calcium cyanamide and kerosene emulsion 

 against various soil infesting insects. In addition, he gives the results of his 

 own field tests with such materials as kerosene emulsion, creosote preparations, 

 corrosive sublimate, sulphuric acid, acetaldehyde, Kopper's solution, and especial- 

 ly sodium cyanide against the grubs oi Popilia japonica. Tables are presented 

 showing rates of application per acre, areas treated, areas examined, dates of 

 treatment and percentages of mortality. After summarizing the present knowl- 

 edge of the effect of treatments of cyanide and of cyanide in combination with 

 ammonium sulphate on soil, Mr. Davis concludes that while many isolated 

 experiments have been made to determine the possible use of sodium cyanide 

 as a soil insecticide, the entire study lacks continuity, and that until a con- 

 sistent and continuous program of work is inaugurated, very little in the way 

 of definite results can be expected. 



October, 1020 Harry B. Weiss, Ncw Bruuswick, New Jersey. 



Mailed October 30tli, 1920 



