August, '09] JOURNAL OF ECONOMIC ENTOMOLOGY 309 



moth, the latter continuing its devastations the present season. ■ It 

 is believed that these outbreaks are due in large measure to the 

 scarcity of native insectivorous birds. Can this be substantiated by 

 observations in other parts of the country or proved by experimental 

 data? Are birds more efficient natural cheeks upon our forest 

 fauna than insect parasites and fungous diseases! Various ento- 

 mologists must possess unpublished data of much value along these 

 lines and we would like to see it collaborated in order that the evi- 

 dence 2uay be carefully weighed and we be in a better position to 

 judge as to the relative efficiency of the various factors maintaining 

 a balance between insect and vegetable life. 



Reviews 



Codling Moth Investigations, by E. D. Sanderson. 19th and 20th 

 Reports of the New Hampshire College of Agriculture and Mechanic 

 Arts, p. 396-498, 1908. 



During the past few years the codling moth has received attention at the 

 hands of numerous investigators, and much has been added to our knowledge 

 of this important apple pest. A recent contribution to the subject is that 

 by Professor Sanderson, comprising somewhat more than one hundred 

 pages, with numerous half-tone illustrations which add materially to the 

 clearness of the text. The article deals primarily with the codling moth in 

 New Hampshire and includes results of observations for the past three 

 years. It is especially timely, since heretofore there has been but little 

 exact information on the seasonal history of the insect in the New England 

 States, representing temperature conditions different from those prevailing 

 in other fruit-growing regions where the species has been carefully studied. 

 A large amount of data is presented and a large series of experiments with 

 remedies are reported upon in detail. 



Under the remarks on hibernation is shown the distribution of codling 

 moth larvae oh the trees during the hibernation period, and also the winter 

 mortality of larvae under natural orchard conditions — facts not previously 

 determined. An examination of seven apple trees in May, 1907, showed 

 that out of 385 cocoons found, 70 per cent, were located on the trunk, and 

 the remainder on the main branches. Of the larvre on the tnmks, 

 97 were within one foot of the crotch; 112 within one foot of the 

 ground; and 60 were between on the middle portion of the trunk. The 

 mortality records of larvae on the seven trees show that 5 per cent, only 

 were alive at the time of examination; 87 per cent, had been killed by birds; 

 4 per cent by fungous disease; and 3 per cent, by cold. 



Data is presented to show the relation of temperature to the pupal stage, 

 and it is calculated that for spring pupae from 470 to 480 degrees are re- 

 quired above 30 degrees P., practically a thermal constant. It is apparent, 



