26 SPRAYING THE APPLE ORCHARD. 



these worms of the second brood become full grown in this 

 latitude, but late in September, when half grown, they form 

 their winter cocoons. It is for this reason that in examin- 

 ing the cocoons in winter some larvae are found hardly half 

 the size of the majority of those full grown of the first 

 brood. The difference in the food habits of this second 

 brood has been observed by many growers and has led 

 some to the belief that the work is that of a different insect. 

 Although but less than five per cent., and probably only one 

 or two per cent, of the larvfe transform to the second brood 



Fig. 18.—" The little worms of the .second brood feed upon or just under 



the surface." 



of moths, yet we find that fully two thirds of the picked 

 fruit which shows the work of the codling moth has been 

 affected by the second brood, which have marred the sur- 

 face or eaten around the calyx, and only about one third of 

 those wormy show the characteristic work of the first 

 brood. Indeed, the bulk of the apples attacked by the first 

 brood fall to the ground as windfalls, and thus the damage 

 done by it usually escapes notice. 



SPRAYING EXPERIMENTS IN 1906. 



Our field work in 1906 was planned both as experiments 

 to show the best time to spray and the best materials to use, 

 and also demo7istralions to show the value of spraying in 

 different localities in southern New Hampshire. The re- 

 sults of such experiments secured from a single season's 



