9 



a quarter of an inch in diameter. In this swelHng the larva changes to 

 the pupal stage, which averages five or six days in duration. 



The adults leave their mines during the latter part of May in 

 southern Illinois, and in central Illinois and in central Ohio during the 

 fore part of June. Since there is but one brood per year the beetles 

 which appear in summer survive the winter in hibernation. They feed 

 for approximately a month before retiring to their winter quarters. 

 This feeding period is also the principal migration season, but as the 

 insect is not a strong flier its spread from one orchard to another is 

 surprisingly slow. 



The beetles have been found in winter quarters as early as June 

 15 in southern Illinois, and by mid-July most of them are so concealed. 

 ■In the Ohio territory and in central Illinois this period is practically 

 complete by August 1, but a few are abroad until early fall. The move- 

 ment to hibernating quarters is more prolonged than that from these 

 quarters in spring. The time of year for the retreat of the beetles is 

 influenced by the weather, hot weather hastening it, and cool, cloudy 

 weather during the summer months delaying it. 



Character of Injury and Extent of Damage 



The damage done by the apple flea-weevil consists in the feeding 

 punctures of the weevils and the mines of the larvae. If the weevils 

 have emerged when the buds are just beginning to show green they in- 

 jure the expanding buds by inserting their beaks into them and, if 

 sufficiently abundant, may prevent their opening. As the leaves open, 

 the beetles continue their feeding, cutting holes entirely through the 

 tender foliage, and occasionally at this stage destroying it outright (see 

 Figure 6). Still later, after the leaves have become full grown, the 

 weevils feed for the most part on the under side, though occasionally 

 one is seen feeding on the upper leaf-surface. They eat out the soft 

 tissue, leaving the epidermis of the opposite side, thus making shallow 

 pits about a twenty-fifth of an inch in diameter. The unconsumed epi- 

 dermis turns brown a few days after the injury, and later breaks away, 

 leaving a hole in the leaf, and when the attack is severe the tree looks 

 as if it had been riddled with bird shot. Leaves on which several weevils 

 have fed will have from a third to half the surface destroyed. When 

 injured to this extent they drop prematurely, and the punctures also 

 atford easy access for the spores of various fungi. Upwards of 2000 

 beetles are frequently found on a single tree, and as each weevil makes 

 from ten to twenty feeding punctures a day, it is easy to understand the 

 amount of injury which can be done in the course of a month's feeding. 

 (See Figures 7 and 8.) 



The mining of the leaves by the larvae is perhaps a little less de- 

 structive in its effect on the host than the feeding of the adult beetles. 

 (See Figure 9.) Where two, three, or even more mines occupy a single 

 leaf, it is rendered almost wholly, if not entirely, functionless. In 



