40 a EXPERIMENT STATION. [Jan. 



A plot of land conveniently located near the laboratory 

 was obtained last spring for use as a garden, and here the 

 various garden pests were studied and methods for their 

 control tested under conditions which could be determined 

 and to some extent regulated. The results were so satisfactory 

 that this w^ork will be continued. 



Tests of the standard insecticides to determine their action 

 and the causes of burning of foliage have been continued. Pure 

 materials have been tested until we know what to expect 

 from them. Commercial brands are now being tried in the 

 same way. The past year has shown that arsenite of lime 

 cannot be safely recommended for use under conditions such 

 as usually are present with the sprayer, too many precautions 

 being required to obtain safety. Further study of this sub- 

 stance has, therefore, been discontinued, and arsenate of lime 

 has been taken up in its place. 



Work on the digger wasps as parasites has made good 

 progress, but a topic of this nature demands either the entire 

 attention of the worker, or a long period before final results 

 can be expected. The former not being possible here under 

 existing conditions, no results are as yet ready to report. 



The study of the European corn borer was begun in 1917 

 by the late Mr. S. C. Vinal, who continued it till his death 

 in September, 1918. The records and observations he made 

 have been brought together by Mr. D. J. Caffrey of the 

 United States Bureau of Entomology, who was also working 

 on some phases of the problem under a co-operative agreement 

 between the station and the bureau, and are now ready for 

 publication. 



Investigations as to methods for controlling the onion 

 maggot, continued from previous years, were practically 

 limited in 1918 to tests of the success of traps in catching 

 the adult flies. Six traps were placed in an area of about 

 one-fourth of an acre, and during the months of INIay and 

 June about 48,000 flies were captured, about 4,500 of which 

 were those of the onion maggot. While it cannot be claimed 

 that these flies were taken before, rather than after, their 

 eggs had been laid, the fact that this field was practically 

 free from the maggots may have some significance in this 



