36 a EXPERIMENT STATION. [Jan. 



to a continuation of studies on this insect, which have already 

 given interesting results. This investigation should and will 

 be carried further. 



Studies on our Common Scale Insects. — Work on this subject 

 in 1918 developed new phases which promise unexpected and 

 possibly important results as to the reaction of these insects 

 to climatic conditions. These investigations will, therefore, be 

 continued. 



Seasonal Appearance of Pests. — Our insect pests vary in 

 time of their arrival each year- with the nature of the season. 

 As successful treatment should begin immediately upon their 

 appearance, if the most successful results are to be obtained, 

 definite information on this subject is much to be desired. 

 Work along this line has been begun, mainly incidental to 

 other observations and taking little extra time, but the results 

 thus far have been very suggestive, and seem to encourage a 

 belief that valuable conclusions of direct benefit in spraying 

 may be obtained. It is too early in this work to predict, but 

 so far this study has indicated the possibility that people in 

 different parts of the State can be given each year definite 

 dates on which to give treatment, comparable with that now 

 given for the calyx spray for the codling moth. 



Tests of Standard Insecticides. — This project has now been 

 under way for a number of years. Its scope is such, however, 

 that final conclusions and the end of the work are not yet 

 in sight, though certain results have already been obtained. 

 About 2,000 different tests on this project were made last 

 summer, and the data are now being studied. It was thought 

 wise this year to include magnesium arsenate in the materials 

 tested, it was being pushed so much on the market, but the 

 results obtained thus far have been to show that it is entirely 

 too injurious to foliage in its present form for safe use. Further 

 tests of it will be discontinued unless it is prepared in a safer 

 form. 



Studies on Bigger Wasps. — This is an Adams fund project. 

 Investigations here have also made progress, though, as usual, 

 less than could be desired. It is now evident that these in- 

 sects have been considerably overrated in importance as para- 

 sites, their reproductive capacity, and therefore the food sup- 



