PREFACE. 



The present series of articles on deciduous fruit insects and insecti- 

 cides, Parts I to VIII, comprises Bulletin 80. 



The first article, on the codling moth in the Ozarks, is a report on 

 two years' study of the life history of this insect, which is very 

 destructive in that locality. For the first time three generations of 

 larvae have definitely been established. 



The cigar case-bearer, treated in the second paper, is an insect 

 that periodically attracts attention by reason of its injuries. During 

 the outbreak of this species in the general region of North East, Pa., 

 during the season of 1908, exceptional opportunity was presented for 

 a study of its life history and habits, as detailed in the paper in 

 question. 



The lesser apple worm was the subject of an article issued in 1908 

 as Part V of Bulletin 68. At that time the egg had not been found, 

 and there was question whether this species fed to any extent upon 

 the twigs of apple. Further observations on this important apple 

 insect are presented in Part III, in which the egg stage is described, 

 although previously noted by Mr. E. P. Taylor, and it was also found 

 that the boring of apple twigs is due to the work of another species. 



The fourth paper, on the pear thrips and its control, comprises the 

 second report upon this species, which is so destructive to deciduous 

 fruits in the San Francisco Bay region in California. The first paper, 

 issued as Part I of Bulletin 68, contained the principal facts in the 

 life history of the insect, which are repeated and extended in the 

 present paper, with the addition of many data resulting from large- 

 scale experiments with remedies in orchards. Practicable control 

 measures are indicated. 



The feeding of the codling moth upon nuts has been occasionally 

 recorded in the literature of this insect, although the evidence has 

 been inconclusive, and it was the consensus of opinion among ento- 

 mologists that the insect never normally fed upon nuts. Part V of 

 the present bulletin details definite extended observations showing 

 that under certain conditions in California the codling moth is a seri- 

 ous pest in its work on English or Persian walnuts. 



Part VI, which deals with the life history of the codling moth in 

 northwestern Pennsylvania, follows in general the plan of treatment 

 of Part I of this bulletin, and constitutes the second article dealing 



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