278 



JOURNAL O'F economic ENTOMOLOGY 



[Vol. 8 



Germination tests carried on during the winter furnished some 

 further light upon the relative values-of the different materials. 



In the field experiments, only those materials which from the 

 previous year had appeared of value, were given a trial. The method 

 of application followed was that of using an ordinary onion planter 

 with the covering wheel removed. This left the seed uncovered in the 

 rows. The different substances were then applied on top of the seed 

 and the rows covered by hand. This manual work was necessary from 

 the fact that it was impossible to secure a machine with the supply 

 tank behind the seed dropper, and for several reasons the alterations 

 could not be made in time. 



It was evident that the plants in rows which had been treated were 

 retarded to some extent in their early growth, as compared to those 

 in untreated or check rows. This caused the plants in treated rows 

 to appear above ground a few days later than in check rows, but as the 

 season progressed they apparently recovered from the slight early 

 check and in the latter part of the summer there was very little, if any, 

 difference apparent. 



As mentioned above, the naphthalene, when used alone, had a 

 decidedly injurious effect upon the germination and caused a very 

 irregular '^stand." However, when diluted by mixing with a substance 

 less powerful as a repelling agent, it appeared safe and, warranted a 

 continuance of its use in the experiments. 



The scarcity of maggots in the experimental plots was very pro- 

 nounced. There were fewer infested plants found in both plots on 

 check and treated rows combined, than in former years had been found 

 in the check rows of one plot alone. In fact, the total number during 

 all the present season was less than one-half those found in 1913 in 

 the check rows of one plot. The number of check rows was the same 

 for both years. 



This extremely light infestation at first gave rise to some doubts 

 as to the possibility of securing anything like trustworthy data. The 

 results that were obtained, however, from the whole season's records, 

 bore out in general those of the previous years, although on a smaller 

 scale, due to the meagre numbers of the maggots found. 



The degree of protection given by the different treatments was ap- 

 proximately the same as before. This was also true in the relative 

 abundance of maggots in check and treated rows, so that although the 

 totals w^ere much smaller, their relative standing agreed with those of 

 the previous year. 



It was very evident that for the successful working out of this plan 

 of applying treatment at the time of planting, a special design of 

 planter would be required. A machine was purchased which seemed 



