Pomona College Journal of Entomology 



Volume 11 M A R C H 1 9 1 Number 1 



FUMIGATION STUDIES— I 

 THE USE OF WATER IN FUMIGATION DOSAGES 



WRIGHT M. PIERCE. 



[The people of this immediate region spend hundreds of thousands of 

 dollars each year for citrus fumigation. They are acutely interested to know 

 just what they are getting, and want to understand clearly the factors which 

 control successful work. Mr. Pierce has taken up this work here in our 

 own region and has gathered a large amount of first hand facts by actually fol- 

 lowing up many contracting fumigators in the field and studying carefully their 

 metiiods and results. His work this year may be gathered under four heads, (I) 

 Use of Water in Fumigation Dosages, (2) Estimating Fumigation Dosages for 

 Trees, (3) Does Contract Fumigation Pay, and (4) Handling Chemicals in 

 Fumigation Work. Some of his first results are presented herewith. He has 

 gathered a remarkable series of photographs in evidence of the points he wishes 

 to make — many more than we are able to present here. — Ed.] 



.An enormous amount of Fumigation is being done in Southern Califor- 

 nia now, and to keep the more destructive scales out of his grove is the most 

 important problem facing (he citrus grower of today. With our poor knowl- 

 edge of parasites and the best ways to use them in our service, it seems that 

 fumigation is now the most efficient process by which the citrus grower can 

 combat the insect pests found here. Within many miles of Claremont prac- 

 tically all of the fumigating done is for the black scale alone, and the cost to this 

 district on account of this pest alone, amounts to tens of thousands of 

 dollars. With this outlay and the prime importance of the work to the whole 

 citrus industry, it becomes a matter of the highest imjiort to study carefully 

 the methods actually emplo\'cd in the district, determining if the methods 

 used are the most efficient ones, if the greatest possible service is obtained from 

 the chemicals used, and if the whole operation is accomplished with the least 

 possible cost to the grower. Tn work so extensively carried on as this is, it is 



