22 MISC. PUBLICATIOiir 16 8, U.S. DEPT. OF AGRICULTUKE 



CAUSE 



The worm, or larva, causing worminess in apples is about three 

 fourths of an inch in length when full grown, and is cream- white to 

 pink- white in color, with a dark-brown head. The insect hibernates 

 in the larval stage in cocoons in crevices in the bark, in trash on the 

 ground, in orchard lug boxes, and in packing sheds. The adults 

 Jbegin to emerge during or shortly after the blooming period. The 

 moths have a wing expanse of one half to three fourths of an inch ; 

 they are brownish gray in color, with a dark-brown spot, crossed by 

 two golden bars, at the tip of each fore wing. 



CONTROL MEASURES 



In most regions the codling moth may be satisfactorily controlled 

 by spraying with lead arsenate, the exact number of applications 

 varying with the locality. The presence of excessive quantities of 

 lead or arsenic on marketed fruits, however, constitutes a potential 

 danger to human health. Because of this spray-residue problem, 

 intensive investigations are now under way. These may result in 

 radical changes in the present codling-moth-control programs. On 

 account of this factor, and because spray programs var}^ so much as 

 between different localities, no detailed schedules will be given here. 

 In planning a season's codling-moth-control operations, growers 

 should therefore be guided by the current recommendations issued 

 by State experiment stations or by the United States Department of 

 Agriculture. 



A great deal can be done by a number of other practices formerly 

 considered supplemental to spraying. Important among these is the 

 use of trap bands, by means of which the grower can capture and 

 destroy from 30 to 50 percent of the worms in the orchard. A re- 

 cent development has been the chemically treated bands, which are 

 automatic in operation, killing the worms which enter them. If 

 banding is to be effective, the trunk and larger branches of the tree 

 should be thoroughly scraped, and the loose flakes of bark caught on 

 a canvas and destroyed, thus eliminating the places normally pre- 

 ferred for cocooning. This forces the worms to go into trap bands. 

 Packing sheds should be kept closed or well screened wherever pos- 

 sible during the period when the moths are emerging, in order that 

 the moths may be prevented from reaching the orchard. Orchard 

 lug boxes and other containers should either be treated with hot 

 v^ater or otherwise to destroy worms which have cocooned in them, or 

 should be kept during spring and earlv summer in a tightly closed 

 storage space. {73; 7J^; 164,- 165; 166^183, p. 36-37; 181^; 19J^; Wl; 

 mi; 213; 2U; 215; 216; 233; 23^) 



CORE ROT 



(PenicilUum, Alternaria, Rliizopus, Physalospora, and Fusarium) 



Apples are sometimes observed which, though sound so far as 

 external appearances indicate, are decayed at the core. The condi- 

 tion is due to infection with some of the common rot fungi, following 

 codling-moth injury, or less frequently following injury by the lesser 

 apple worm. It sometimes follows cracking at the blossom end, and 



