30 MASS. EXPERIMENT STATION BULLETIN 417 



Prevalence of Cranberry Insects in 1943. 



1. Bumblebees and honeybees rather abundant nearly everywhere on Mass- 

 achusetts bogs during the cranberry flowering; somewhat less abundant than 

 in 1942. 



2. Cranberry fruit worm {Mineola) much more prevalent than for quite a 

 number of years. 



3. Infestation by gypsy moth (Porthetria) rather light in Plymouth County 

 but somewhat greater on most of the outer Cape than in 1942. 



4. Black-headed fireworm normally abundant, about as in 1942. 



5. Firebeetle (Cryptocephalus) , almost none. 



6. Spotted fireworm (Cacoecia) rather prevalent, but less so than in 1942. 



7. False armyworm (Xylena) normally abundant, less prevalent than in 1942. 



8. Cranberry girdler (Crambus) more abundant than for many years. 



9. Cranberry weevil {Anthonomus) normal in abundance. 



10. Cranberry spittle insect and tipworm fully as troublesome as usual. 



11. Spanworm infestations generally light. 



Control of Cranberry Bog Weeds. (Chester E. Cross.) About 50 experiments 

 in chemical weed control gave the following results: 



1 . Kerosene is decidedly more toxic to rushes when sprayed in April and early 

 May than at any time later in the growing season. At 400 gallons per acre, 

 kerosene killed Junciis bufotiius, J. canadetisis, J. acuminatus, J. effusus, and J. 

 pelocarpus. No injury to cranberry flower buds resulted from kerosene spraying 

 till treatments were made on May 28. 



2. Gasoline sprayed on bogs at 200 and 400 gallons per acre caused no injury 

 to vines in treatments made before May 15. Horsetail, loosestrife, and various 

 grasses and rushes were killed by the sprays. 



3. Various concentrations of lime-sulfur solution were sprayed on bog weeds 

 late in April. Neither weeds nor cranberry vines were injured by them. 



4. Ammonium sulfamate sprays were as toxic to cranberry vines in April and 

 May as they are later after the development of new growth. Ivy sprayed with 

 these solutions before sending out its leaves in the spring showed no injury. 



5. Established clumps of Jiincus canadensis were completely killed on new 

 bog by pouring into each 25 cc. of a copper sulfate solution of 1 pound in 20 gal- 

 lons of water. The adjacent hill cranberry vines were riot injured. 



DEPARTMENT OF DAIRY INDUSTRY 

 J. H. Frandsen in Charge 



Nutritive Value of Milk — Plain versus Chocolate Flavored. (W. S. Mueller.) 

 The toxicity of cocoa powder was found to be correlated with its tannic sub- 

 stances content. Therefore, if cocoa could be analyzed accurately for tannic 

 substances, then dieticians could select a cocoa powder which is low in these 

 substances and thus avoid most of its toxic effects. 



None of the various methods for the determination of tannic substances in 

 cocoa powder which were investigated proved entirely satisfactory. Com- 

 mercial cocoa powder contained on an average 11 percent of tannic substances, 

 as determined by the Ulrich method, which is the one most commonly used today. 

 Ulrich's method was modified and improved. By this improved method, com- 

 mercial cocoa powder contained an average of only 9.5 percent of tannic sub- 

 stances. 



