2 BULLETIN 189, U. S. DEPARTMENT OE AGRICULTURE. 



tigations of this insect throughout the United States, giving particular 

 attention to time of appearance of the different broods at various 

 altitudes and latitudes. The work was conducted by or under the 

 immediate direction of the authors of this paper and was continued 

 for three consecutive years at several points locatedrin Virginia, West 

 Virginia, and Maryland. 



The writers are greatly indebted to the large number of fruit growers 

 in the various localities where the investigations were carried on for 

 the free use of orchards in which to obtain banding records, for build- 

 ings to shelter rearing jars, and for other courtesies. During the 

 progress of the work many essential suggestions were made by 

 Prof. A. L. Quaintance, in charge of Deciduous Fruit Insect Investi- 

 gations, under whose direction the studies were made. 



LOCALITIES IN WHICH INVESTIGATIONS WERE MADE. 



The studies described herein were conducted at Charlottesville, 

 Fishersville, Greenwood, and Winchester, Va. ; Keyser, French Creek, 

 and Pickens, W. Va. ; and Hagerstown, Smithsburg, and Hancock, Md. 

 The senior author had charge of the investigations in West Virginia 

 and the junior author had charge in Virginia and Maryland. At 

 several of the points mentioned only partial or incomplete records 

 were obtained. The similarity of conditions at Sniithsburg and 

 Hancock, Md., and Keyser, W. Va., to other localities where records 

 were being kept, together with a shortage of the fruit crop and the 

 difficulty of visiting so many places at sufficiently frequent intervals, 

 led to the discontinuance of operations at these points after the 

 first year. 



NATURE AND EXTENT OF THE INVESTIGATIONS. 



The work was conducted by selecting, for banding, from 10 to 15 

 unsprayed bearing apple trees of late ripening varieties in each 

 locality. Wherever it was possible medium-sized trees with smooth 

 bark were chosen. In some cases such trees could not be found and 

 old trees with rough bark were used. The rough scales of bark were 

 scraped from the trunks and from the bases of the larger branches of 

 these old trees, but even then they were much less desirable for the 

 purpose than the younger, smooth-barked trees. 



In the spring, before the first-brood codling-moth larvse had com- 

 menced to leave the fruit, burlap bauds were tied around the trunks 

 of the trees 2 or 3 feet above the ground, and in some cases additional 

 bands of the same material were placed around the bases of the larger 

 branches. The trees were all tagged and an individual account kept 

 as to the number of larvae going under the bands to "spin up." The 

 bands were removed and examined at frequent intervals and the 



