44 



CIRCULAR 270, U.S. DEPARTMENT OF AGRICULTURE 



in August and leaving the bands on until after the fruit has been 

 harvested. 



ANTS 



Orchards of the Pacific Northwest are sometimes troubled by 

 ants, particularly the large pugnacious red ants {Formica spp.) that 

 build nests in the ground, often covered with rather conspicuous 

 heaps of dried stems and twigs of plants. These ants are attracted 

 to the trees primarily to feed on the honeydew excreted by aphids. 

 At times the ants may chew the blossoms and cause direct injury in 



that manner. If the 

 nests are not adjacent 

 to the trees or other 

 valuable plants, the 

 ants may be eradica- 

 ted or greatly reduced 

 in numbers by placing 

 about an oimce of 

 granular calcium cy- 

 anide in the center of 

 the hill or nest, sev- 

 eral inches below the 

 surface, and covering 

 it with dirt, This 

 material is dangerous 

 to use near growing 

 plants, and in such 

 cases some control 

 may be obtained by 

 drenching the nests 

 with water containing 

 a pyrethrum extract. 

 This should be used 

 at the strongest dilu- 

 tion recommended 

 by the manufacturer 

 (usually about 1 gal- 

 lon to 200 gallons of 

 water). 



CHERRY INSECTS 

 SAN JOSE SCALE 



The San Jose scale 

 is not often very 

 injurious to sour 

 cherries, but it does 

 As these trees usually 

 thoroughly, and it is a 

 to the upper branches 

 This is an almost sure 

 with the scale. Treat- 

 pear trees (p. 10). The 

 the trees and spraying 



Figure 54. — Larvae of dock sawfly feeding on dock leaves. Four 

 Times natural size." 



a great deal of damage to sweet cherries, 

 grow large, the tops are difficult to spray 

 common thing to see dead leaves clinging 

 of large sweet cherry trees during the winter. 

 indication that these branches are infested 

 ment is the same as for scale on apple and 

 tops may often be reached by climbing into 

 the tops first. 



