REPORT OP THE STATE ENTOMOLOGIST 1903 150 



this scale insect is a. very serious enemy, and unless efficient 



measures are promptly adopted for its suppression, very great 



injuries may be caused. 



Summer washes 



This pernicious insect breeds with such extraordinary rapidity 

 during the summer, that ordinary applications of whale oil soap 

 or kerosene emulsion are not entirely satisfactory, since at the 

 strengths usually employed only the crawling young and smaller 

 scale insects are killed. It frequently occurs that an infesta- 

 tion is discovered in midsummer and the owner wishes to do some- 

 thing at once. The unsatisfactory results with the above named 

 washes led Mr P. L. Huested, nursery inspector of the Depart- 

 ment of Agriculture, to experiment with a mechanical 20$ crude 

 petroleum emulsion, which was applied in July with a kerowater 

 sprayer to peachtrees. A test of this material was made in a 

 very badly infested orchard in the summer of 1902, and beyond 

 causing some of the foliage to drop where it was the thickest, par- 

 ticularly in places where a 25$ emulsion was used, as was the 

 case in certain areas, no serious injury to the trees followed the 

 treatment. The results were so satisfactory that the same course 

 was pursued last summer with equally gratifying effect so far as 

 injuring the trees was concerned, though at the time it did not ap- 

 pear as if the application was effective enough in killing the scale. 

 Subsequent observations, however, have shown that it was more 

 beneficial than at first supposed. In spite of this, we still feel 

 some hesitancy in recommending this treatment in summer, ex- 

 cept, perhaps, where the pest is breeding in very large numbers. 



This condition of affairs led us to undertake a series of experi- 

 ments for the purpose of ascertaining if it were possible to make 

 some combination which, while not injuring the foliage, would 

 remain on the trees and be effective for some weeks after applica- 

 tion, and at least kill the crawling young as they came from under 

 the protecting scales of the females. The late Professor Lowe 

 conducted some experiments along this line, and our work has been 

 a continuation of that with modifications. It appeared to us as 

 though a lime-sulfur combination, possibly without boiling, could 



