76 EXPERIMENT STATION. [Jan. 



ment of this kind is that now l)eing conducted by the Bureau of 

 Entomology of the United States Department of Agriculture 

 and those in charge of the gypsv moth work in Massachusetts, in 

 importing from the old world the parasitic and other enemies of 

 the gypsy and brown-tail nir.ths, in the hope that they may be- 

 come established in this country and bring these pests under 

 control. 



No one seems to know, how^ever, how eifective parasites really 

 are; conceding their importance, we have only the most general 

 statements on the subject, and almost the only paper giving 

 more than these is a short one by Dr. L. O. Howard, entitled 

 " A Study of Insect Parasitism." 



It would seem most desirable to substitute statistics for guess- 

 work on a subject so important as this, and therefore the scope 

 of parasitism by the insects of a restricted group, the conditions 

 favoring and checking it, and all the factors entering into the 

 problem have been taken up for ]u-olonge(l study, and it is hoped 

 that tangible results may in time replace the vague generaliza- 

 tions on this subject which, thus far, are all that have been 

 availal)le. 



Investigations on spraying have been continued since the last 

 report, but with disappointing results. As was stated last year, 

 the first step was to obtain pure spraying materials, and it was 

 supposed that these were available, as reliable manufacturers 

 offered them as such. To be certain, however, these were ana- 

 lyzed, and the results showed that the materials were not as 

 pure as was necessary for the purpose, making it necessary to 

 make these materials at the station. This has held up the work 

 to some extent, for while considerable time was spent in applying 

 the materials to various plants, and watching the results, the 

 later discovery of the unreliability of the materials used has 

 made valueless the experimental work done with them. New 

 spraying materials made here must, therefore, be obtained to 

 use in these experiments, in order to obtain the results needed 

 as a basis for the study of the commercial materials which is to 

 follow, and at present the work is at a standstill till these ma- 

 terials can be prepared. It is expected, however, that they will 

 be available for use during the coming summer. 



