43 



of western Ontario there are two generations, the second being- inva- 

 riably the more destructive. The observations of Atkins, Harvey, 

 and Munson agree with those of Harris. Slingerhmd says in 1898 

 that his observations indicate that in New York a large number of 

 the larvfe of the iirst generation develop into moths, the percentage 

 transforming depending upon the weather conditions of the season. 

 In 189-1: Smith found l)y a series of observations that the larvte col- 

 lected in midsummer did not transform further that \^ear, but hiber- 

 nated. Later, in 1897, he states that near New Brunswick, N. J., there 

 is positively onl}^ a single annual generation, and, further, that south 

 of Burlington (Jount}" there is at least a partial second generation. 

 In addition to the observations already given of conditions quite simi- 

 lar to these in New Jersey, we tind that Trimble in 1865 carried out a 

 very careful and accurate series of experiments upon the life history 

 of the codling moth at Newark. He found that on August 10 there 

 were three pupa> among the insects under observation, and that on 

 August 20 many moths had emerged; on August 23 he found that one 

 in five of the larvre had transformed. Sanderson tinds that there is 

 one generation and a partial second generation in Delaware. He 

 states that of the larvae found July 31 about 29 transformed and 5 

 remained as larvae. Taking these numerous observations and the data 

 given in regard to them into consideration, we must conclude that 

 Doctor Smith's observations are too few in number and do not justify 

 the assertion that there is but one generation of the codling moth at 

 New Brunswick. Man}- observers in widely different sections of the 

 United States have found two generations clearly defined. Lc Baron 

 states that " in the latitude of Chicago a great majority of the moths 

 of this brood (first) emerge the last two weeks in July." Kiley, after 

 many years of close ol^servation, states that the insect is "invariably 

 two l)rooded in Missouri." Popenoe and Marlatt found two genera- 

 tions in Kansas. Gillette indicates two generations in Iowa. 'Walton 

 by breeding experiments discovered two generations in the same 

 State. From a series of observations extending over several years, 

 checked by breeding experiments, Cordley concludes that there are 

 two generations at Corvallis, Oreg. Koebele says there are two gen- 

 erations in the Santa Cruz Mountains of California, and the insect 

 probably does not differ in its habits throughout the State. Based 

 upon one of the most extensive studies of this question that has ever 

 been made, Gillette arrived at the conclusion that there are two 

 generations in Colorado. Cooley sa3's that in 1902 there were two 

 generations at Missoula, Mont. Forbes indicates a third generation 

 in Illinois, based upon the fact that very j^oung larva^ were found on 

 Octob'er 1. Coquillett states that his notes indicate that the insect 

 has three generations in California. Washburn says there are three 

 to four generations at Corvallis, Oreg. Card gives two to four in 



