1920] economic; zoology ENTOMOLOGY. 351 



wheat causecl l)y the Columbian ground squirrel (Citcllus volunihianit.'i colnnt- 

 bi(iniii<), individuals were placed in inclosed plats in wliich a good variety of 

 wheat had l)een sowed on fallow Palouse wheat land. The several plats and 

 their corresponding checks were harvested on July 30, the differences taken, 

 and tilt' damage carefully calculated. 



It was found that during tlu> 130 days of activity from March lili to .Tuly 30 

 the male squirrel in yard 1 had destroyed 44 lbs. of wheat. A female squirrel, 

 \\hich gave birth to two young squirrels about May 19, was placed in a yai'd 

 on Api-il 14 and 51 lbs. of grain were destroyed by July 30. Computing the 

 annMint of destruction on the basis of a nonnal 130-day season, 1 young or 1 

 female brooding scpiirrel will destroy 51 lbs. of grain. In a third test in which 

 a male s(iuirrel was placed in a yard on May 15 to determine when th(> greatest 

 damage was done to the crops, 5G lbs. of wheat were destroyed by July 30, 

 showing that practically all the damage was done in 7G days of stem cutting 

 and head destruction. The average destruction per squirrel in the experiments 

 described was .50 J lbs., which at a price of .$2.10 iK»r bushel for hard winter 

 wheat was worth $1.76. 



In an experiment in which a female, suckling four young, fairly mature 

 scpiirrels, was given fresh white clover sod, it was found that she ate ^ lb., 

 or 17.2 per cent of her own weight per day. At this rate, 385 squirrels would 

 consume the pasture of one cow in a day, or 96 squirrels w(mld devour the 

 pasture of one sheep in a day. 



A brief sunnnary is given of the life history of this species and the methods 

 of control, including gassing, poisoning, and trapping, are described. 



Facts about winter and summer robins in Ohio, S. G. Hakry (Mo. Bui. 

 Ohio St a., 5 {1920), No. 3, pp. 9Jf-96). — This Is a brief account of the American 

 robin in which attention is called to the fact that there are northern and 

 southern races. The forms found in Ohio during the winter months represent 

 the more hardy or northern race. They are transients, the majority being 

 Canadian birds. During the unusually .severe winter of 1912, robins wintered 

 in Ohio in large numbers, u flock of more than a thousand individuals having 

 been observed from time to time throughout the winter. The fruit of the 

 flowering dogwood (Comus floriila) is the staple winter food of the robin hi 

 the vicinity of Wooster. 



[Ileport of cntoniolofiical work] {Indinna Sta. Rpt. 1919, pp. 3.i-S6). — 

 From a systematic study of the life history of the codling moth, which was 

 the most important work, the following tentative conclusions are drawn: 

 "Between June 15 and August 15, the moths are constantly emerging but in no 

 greater numbers at one time tlian at another. During liot weather the young 

 larvre may hatch in from 6 to 8 days from the time the moth emerges. Codling 

 moths ai)parently do not mate on the wing. The larvre may be poisoned after 

 they have eaten under the skin of the apple. In order to keep apples free 

 from codling moths, it is necessary to keep the surface of the apple covered 

 with poisons from the time the blos.soms fall till the last of August." These 

 conclusions for the year 1919 are said to be practically in line with those 

 obtained during the two years jtnwious. 



In investigations conunenced the previous year for the purpose of determining 

 the effect upon bees of arsenic compounds applied while fruit trees are in 

 bloom, two bearing trees were screened in with wire screen and a colony of 

 bees place<l in each. Arsenicals were applietl the trees, in one in a liquid and 

 in the other in dust form. Observations were made from April 30 to May 15. 

 Dead bei^s were gathered and counted at intervals, and the results showed a 

 mortality of about 70 per cent for the sprayed tree and 46 per cent for the 



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