8 



CIRCULAR 270, U.S. DEPARTMENT OF AGRICULTURE 



oil. Excessive residues from this material must be removed by wiping 

 or washing the fruit before it is marketed. 



Severe infestations of the codling moth are difficult to control by 

 spraying alone. In such cases some supplemental measures will be 

 very useful. The trees may be scraped thoroughly to remove all of 

 the loose bark under which cocoons might be spun. Bands of corru- 

 gated paper, treated with a mixture of beta-naphthol and oil, 3 may 

 then be placed on the trees not later than the first week of June. 

 Many worms will spin cocoons in the bands and will be destroyed by 

 the chemical. The bands should be removed and burned the following 

 winter and fresh ones applied the next year. In pruning, trees 

 should be kept open enough to permit all parts to be sprayed thor- 

 oughly. Each cluster should be thinned to a single fruit and all 

 wormy fruit removed and destroyed. Worms that have spun cocoons 

 in picking boxes and packing sheds should be destroyed or the result- 

 ing moths prevented from reaching the orchard. The boxes may be 

 placed in a shed that is kept tightly closed during the spring and 



summer to prevent the escape of 

 the moths, or boxes and sheds may 

 be sterilized. 



SAN JOSE SCALE 



The San Jose scale (Aspidiotus 

 perniciosus Comst.) is potentially 

 capable of doing more damage than 

 any other insect occurring in the 

 orchards of the Pacific Northwest. 

 It not only renders the fruit un- 

 marketable, but it lolls the twigs 

 and limbs, and, if not controlled, 

 it eventually kills the tree or at 

 least so devitalizes it that it is worthless. Actually, the amount of 

 damage done by the San Jose scale is much less than that caused by 

 the codling moth, because effective control is easier, and fruit growers 

 generally know the danger and keep the scale under control. 



The scale insect feeds by sucking the plant juices from the twigs 

 and larger branches and from the fruit and foliage. It causes small 

 reddish spots, particularly on the fruit, and the presence of the scale 

 is often first made evident by the appearance of these spots. (Fig. 6.) 

 The red discoloration also occurs on scale-infested leaves and in the 

 bark. It cannot be seen on the surface of the bark, but is disclosed 

 by cutting into infested twigs or limbs. The bark has a roughened 

 and grayish appearance (fig. 7), and if it is scraped a yellowish liquid, 

 coming from the crushed bodies of the insects, appears. Infestations 

 are also manifested by dead twigs scattered about the tree and by 

 the tendency of the leaves on infested branches to remain on the 

 trees during winter. However, in irrigated districts apple leaves 

 often remain on uninfested trees for at least a part of the winter. 

 Although present methods of control are adequate and are keeping 

 the scale in check, an infestation should not be regarded lightly. If 

 spraying is neglected the scales can become very numerous in a sur- 



3 Information on how to make and use these treated bands may be obtained from the Bureau of Entomol^ 

 ogy, U.S. Department of Agriculture, Washington, D.C. 



Figure 



Apples spotted by the San Jose scale. 



