30 University of New Hampshire [Sta. Bui. 330 



3 covers produced 8.08 per cent scabby apples, and those sprayed with 

 2 covers, 9.24 per cent. 



Apples showing scab spots ranging- in size from 1.105 mm. to 

 8.930 mm. were placed in storage at 4°C and were examined at the 

 end of 92 days. The fruiting area in such small scab spots is always 

 smaller than the infected area. Growth in storage consists in the en- 

 largement of the fruiting area, not as a general rule of the infested 

 area as a whole. The diameter of the fruiting area increased 41.05 

 per cent in size during the period of storage, but the diameter of the 

 visibly infected area increased only 13.4 per cent. 



Elgetol, a proprietary coal-tar dye, is also being used in an effort 

 to control apple scab. The Elgetol is made into a spray and applied 

 to the dead leaves on the ground in the orchard. This procedure ap- 

 pears to have some merit, but further experimentation must be done 

 before definite conclusions are warranted. 



(Hatch Fund) 

 Seed Certification (Stuart Dunn) 



Forty-seven and three-eighths acres of Green Mountain pota- 

 toes were entered for certification and the entire acreage passed. Five 

 and one-fourth acres of Chippewas and one-half acre of Irish Cob- 

 blers were entered and passed. Besides these, there were five and 

 one-half acres of Houmas and other newer varieties entered and 

 passed, making a total of 58^ acres. 



(Miscellaneous Income) 



ENTOMOLOGY 



Penetration of Ovicides (W. C. O'Kane and J. G. Conklin) 



The investigations in 1940 have been directed toward determin- 

 ing the ovicidal properties of various mineral oils, with special refer- 

 ence directed toward the relationship of viscocity to penetration and 

 to ovicidal action. To facilitate this phase of the work, a glass device 

 was constructed by the experimenters to atomize the oils. The atom- 

 izer was placed in the top of a bell jar and the spray directed down- 

 ward for definite time intervals onto exposed insect eggs. 



Eggs of the bean weevil (Acanthoscelides obtectus) were used in 

 much of the work, supplemented with eggs of the Mexican bean 

 beetle (Epilachna varivestis) and the confused flour beetle (Tribolium 

 confusum). Five mineral oils were used, representing viscosities 

 of 50 and 100 Saybolt, and sulfonation values of 75 and 95. 



The results available to date are not conclusive. Further ex- 

 perimentation will be required before relationships can be clearly 

 established. 



(Adams Fund) 



Penetration of Contact Insecticides (W. C. O'Kane, J. G. Conklin, 



L. C. Glover, and R. L. Blickle) 

 In the first half of 1940, investigations were continued to de- 

 termine penetration of various liquids through the integument of an 



