4 BULLETIN 189, U. S. DEPARTMENT OF AGRICULTURE. 



pupae" and "first-brood moths." These moths in turn produce 

 " second-brood eggs" and "second-brood larvae." Where "second- 

 brood pupae" and "second-brood moths" occur they may produce 

 "third-brood eggs" and "third-brood larvae." 



INVESTIGATIONS AT CHARLOTTESVILLE, VA. „ 



DESCRIPTION OF LOCALITY. 



Charlottesville is situated at the foot of the eastern slope of the 

 Blue Ridge Mountains, at an elevation of 400 to 500 feet above sea 

 level. In the immediate vicinity of the city there are several large 

 and profitable bearing apple orchards, as well as a considerable acre- 

 age of young orchards planted ■within the last four or five years. Its 

 own interests, therefore, as well as its proximity to the large orchards 

 of the Blue Ridge section, make Charlottesville of considerable im- 

 portance as a commercial apple-growing center. Investigations of 

 the seasonal life history of the codling moth were carried on in this 

 section in 1911, 1912, and 1913. Only the work of the last two years, 

 however, was considered of sufficient value to be included in this 

 report. 



INVESTIGATIONS IN 1912. 



SPRING-BROOD MOTHS. 



A large proportion of the larvae collected in the orchard in the fall 

 of 1911 succumbed to cold or disease the following winter, and the 

 rearing material available for moth emergence was consequently 

 rather limited. On account of the small number of insects reared 

 and some irregularity in the observations the records are not in- 

 cluded in detail. Moths were first observed in the rearing cages at 

 Charlottesville on May 7, and at Greenwood, where conditions are not 

 far from those at Charlottesville, adults began appearing about May 8. 

 Also the summer brood of moths emerged in the rearing cages at Char- 

 lottesville 45 days later (June 20), which is about the interval that 

 must elapse between the two broods of adults in that latitude. There- 

 fore we may safely assume that in 1912 the emergence of spring-brood 

 moths began in the orchards at Charlottesville soon after May 1. 



FIRST-BROOD MOTHS. 



Table I gives the time of emergence of 247 moths that issued from 

 band-collected material at Charlottesville in 1912. Beginning on 

 June 20, emergence continued through the rest of June, the whole of 

 July, and about half of August. One moth emerged as late as 

 September 2. 



