28 MASS. EXPERIMENT STATION BULLETIN 305 



A Study of the Possibilities of Milk, Cream, and Plastic Cream in ttie Devel- 

 opment of New Products such as Combinations with Honey, Fruits, and Flavors 

 of Various Kinds. (J. H. Frandsen and C. R. Foskett.) This project is well 

 under way. Several batches with varying percentages of honey, cream, fruits, 

 and nuts of various kinds have already been made and partially studied. 



DEPARTMENT OF ENTOMOLOGY 

 A. I. Bourne in Charge 



Investigation of Materials Which Promise Value in Insect Control. (A. I. 



Bourne.) The early spring of 1933, like that of 1932, was characterized by fa- 

 vorable weather conditions for dormant and delayed dormant spraying and very 

 little interruption of spraying operations resulted. The delayed dormant appli- 

 cation of oils was made on April 20 and 21. Strong winds, which promoted rapid 

 drying, prevailed during both days. Due to the protected position of the ex- 

 perimental blocks, there was no interference with the application. Following 

 the application was a week of uniformly cold weather, with temperatures not 

 low enough to cause any breakdown of the oil sprays but sufficient to retard the 

 rate of bud development so that ample time was allowed for the application 

 of oils. 



The inveatigation narrowed down to a study of comparatively few samples 

 which appear to be outstanding in their class and show promise of effectiveness 

 worth\- of recommendation. Oil emulsions of the General Chemical Company, 

 of the Niagara Sprayer and Chemical Company (Peninsula Oil Emulsion), and 

 of the California Spray Chemical Company were included in the tests. The 

 new type of "pourable" Kleenup proved to be fully as effective as the older type 

 and much more convenient to handle. 



In the face of a comparatively light infestation, all of the oils tested showed 

 excellent control, even at moderate dilutions. This emphasizes the fact that 

 against a moderate infestation of red mite thoroughness of application is of even 

 greater importance than the particular brand of oil used, and that moderate 

 dosage is sufficient under these circumstances for satisfactory control. 



Preliminary tests were made with the Vapo-Duster, a new development in the 

 use of oil sprays. By this process refined oils, either alone or combined with 

 highlv concentrated insecticide or fungicide materials, are diluted with air to 

 form a fog which rapidly envelops plants or trees and covers any pests present 

 with a uniform film of the active material. In such an application oils are used 

 undiluted with water, and the spray material is atomized and driven upon the 

 plants and pests at considerable pressure. This method eliminates the necessity 

 of hauling large quantities of water and the loss of time for frequent refilling. 

 The fixed type of discharge on the present machine will require modification 

 for adaptation to average orchard conditions. The new method, however, 

 reduces the time of application very materially, and on those trees where thorough 

 coverage was secured, a very high percentage of overwintering eggs of red mite 

 was killed. The effectiveness was equivalent to (hat of the conventional oil 

 sprays. 



In tests against the Mexican bean beetle, Dutox, a commercial fluosilicate 

 compound, was applied as a dust and used at dilutions of 1 part to 2 and 1 to 3 of 

 hydrated lime. No injury to bean foliage resulted from either application. 

 From the results of previous tests no injury would be expected from this material 

 at these dilutions except under conditions of very high temperature and humidity. 



