Feb., 1927] PROGRESS OF AGRICULTURAL EXPERIMENTS 9 



A number of observations were also made to ascertain skin tem- 

 perature of cows in the milking herd. 



DAIRY PRODUCTS 



A Study of Some Important Factors Affecting Viscosity of Ice Cream 

 Mix — ( Purncll Fund) 



The influence of certain factors on the viscosity of the ice cream 

 mix and the relation of viscosity to whipping quality were studied by 

 H. F. DePew, who notes the following results: 1. Homogenization 

 greatly increased tlie viscosity of the mix; the higher the homogeniza- 

 tion pressure, the greater the viscosity. 2. Gelatine increased the vis- 

 cosity of the mix. 3. Pasteurization of the mix at 150° F. for 20 

 minutes and homogenization at this temperature produced greater 

 viscosity than when the mix was cooled to 110" before homogenizing. 

 4. Viscosity was increased by aging the mix at temperatures between 

 32° and 40°. 5. A mix containing Sweetened condensed milk showed 

 greater viscosity than one in which skim milk i^owder was substituted 

 for condensed skim milk. 6. A longer period of freezing was nec- 

 essary to obtain the same overrun when a very viscous mix was 

 frozen as compared with one witli less viscosity. 



ECONOMIC ENTOMOLOGY 



European Corn Borer — (Adams Fund) 



The season has been one of imusual interest in the life history 

 studies of the Euro{)ean corn l)orer. In 1925 the first over-wintering 

 larva to enter the i)upal stage piijiated on Alay 18. This was very 

 hite and sliould be com])ared with Ai)ril 28 of the preceding year. 

 In 1926 the season was late again, and tlie date of first pupation was 

 again May 18; but as the spring continued, the retarded state of insect 

 life became more and more evident. This effect persisted throughout 

 the season and grew even more emphasized as the summer drew to a 

 close. 



For exami^le, the first eggs laid by adults of the over-wintering gen- 

 eration of the current year were found June 14 last year, but not until 

 June 25 this year. The first larva of the succeeding generation hatched 

 June 22 last year, but not until July 3 this year. Pupation of the larvae 

 from this generation began July 21 last year but not until August 8 

 this year. Whereas the first adult of the corresponding generation 

 emerged Aug. 5 last year, the first adult was not found until Aug. 

 19 this year. And finally, the first larva of the succeeding generation 

 hatched Aug. 19 last year, but not until Sept. 12 this year. 



As a net result of this situation it now appears imlikely that Euro- 

 pean corn borer larva^ of the generation just described will reach suf- 

 ficient size to pass the coming winter successfully. Larvae of the 

 earlier generation will over-winter no doubt in the normal manner. As 

 in other seasons there are larva* of the early generation that enter hi- 

 bernation at once and do not transform until the following season. 



