ANNUAL REPORT, 1938 65 



Naphthalene and Similar Compounds as Greenhouse Fumigants. (W. D, 



Whitcomb, Waltham.) Experimental fumigations with clilorinated naphthalene 

 compounds as greenhouse fumigants were continued with very encouraging 

 results. A chlornaphthalene oil killed 92.51 percent of red spiders on carnation 

 in one fumigation and 100 percent in two fumigations. Other chlornaphthalene 

 compounds were slightly less effective, the mortality of red spider by fumigation 

 decreasing about 5 percent for each atom of chlorine added to the naphthalene. 



Mixtures of 2 parts of chlornaphthalene oil with 1 part of the higher chlorinated 

 naphthalene waxes killed 100 percent of the red spiders in two fumigations, but 

 in one fumigation the mortality of red spider decreased as the atoms of chlorine 

 in the mixture were increased. 



The addition of 25 percent paradichlorobenzene crystals to the chlornaphthalene 

 oil gave a mortality of 89.42 percent; and a mixture of equal parts of chlornaph- 

 thalene oil, paradichlorobenzene crystals, and naphthalene crystals killed 92.92 

 percent of the red spiders. 



The most effective mixtures were those containing 25 percent naphthalene 

 crystals in chlornaphthalene oil and 25 percent chlorinated naphthalene soft 

 wax in chlornaphthalene oil. Both of these mixtures killed all of the red spiders 

 in one fumigation. 



Potted carnations infested with the common red spider mite Tetranychus 

 telarius L.) were used and no injury to the plants resulted from normal fumiga- 

 tions. The work was done in an experimental fumigation chamber with 3^ ounce 

 of the fumigant for each 1000 cubic feet and an exposure of 6 hours at 70° F. and 

 60 percent relative humidity. 



FEED CONTROL SERVICE 



Philip H. Smith in Charge 



The Feed Control Service comprises not only feed inspection, but several other 

 activities, as listed below: 



Feed Control (General Laws, 1920 Chapter 94) 

 Seed Control (General Laws, 1927 Chapter 94) 

 Dairy Law (General Laws, 1920 Chapter 94) 

 Advanced Registry Testing 

 Miscellaneous Work 



Feed Control. (P. H. Smith, A. F. Spelman, J. \V. Kuzmeski, L. V. Crowley, 

 F. A. McLaughlin, J. T. Howard.) During the fiscal year 1,721 samples of feeding^ 

 stufTs were officially collected and examined in the control laboratories. The gross 

 receipts from the registration of feeding stuffs in 1938 (calendar year) were $23,400, 

 derived from 1,170 brands at $20 each. 



Dairy Law. (P. H. Smith, J. T. Howard, H. L. Allen.) During the year ending 

 December 1, 1938, 6,369 pieces of Babcock glassware were tested. Condemned 

 glassware consisted of one milk test bottle and one pipette. One hundred and 

 ten certificates of proficiency were awarded; and 227 creameries, milk depots,^ 

 and milk inspectors' laboratories were visited in order to check methods and pass 

 upon equipment in use. As a result of this inspection, seven machines were 

 condemned. 



Advanced Registry Testing. (P. H. Smith.) On March 1, 1938, the work of 

 Advanced Registry Testing was transferred to the Extension Service. While this 

 work has been supervised by this department since its inception in 1902, it was 



