ORCHARD INSECTS OF THE PACIFIC NORTHWEST 



49 



SHOT-HOLE BORER 



Cherry trees are sometimes attacked by shot-hole borers (Anisan- 

 drus pijri Peck), which make small round holes in the trunks. For 

 a description of this insect and its habits, and for methods of prevent- 

 ing its attacks, see page 33. 



PEAR THRIPS 



The pear thrips (Taeniothrips inconseguens Uzel) is sometimes 

 injurious to cherries in western and northeastern Oregon and in south- 

 eastern Washington. 

 Its habits and con- 

 trol on cherry trees 

 are much the same as 

 on prune trees 

 (p. 54). 



PRUNE AND PLUM 

 INSECTS 



SAN JOSE SCALE 



The San Jose scale 

 is a very important 

 pest of prune and 

 plum trees. For de- 

 scription and treat- 

 ment see pages 8-1 1 . 



EUROPEAN FRUIT 

 LECANIUM 



The European 

 fruit lecanium, or 

 brown apricot scale 

 {Lecanium corni 

 Bouche), seldom ap- 

 pears in the irrigated 

 valleys but is some- 

 times common else- 

 where. It. is a rela- 

 tively large, hemi- 

 spherical, brown, 

 more or less \vrinkled scale insect (fig. 59) occurring on the twigs and 

 limbs of prune, apricot, and peach trees, and also on other fruit and 

 shade trees, including pear, apple, cherry, quince, alder, ash, boxelder, 

 locust, poplar, and willow. It passes the winter as a nearly mature 

 insect, laying eggs beneath the shell in the spring. These hatch from 

 May to July, and the young settle on the twigs and leaves. There 

 is only one generation a year. This scale may be controlled with the 

 usual dormant-season applications of lime-sulphur or oil emulsion 

 (tables on pp. 68 and 69), the oil being more effective than the 

 lime-sulphur. 



APHIDS 



Four or five species of aphids occur on prunes and plums in the 

 Pacific Northwest. All have similar habits and may be controlled 

 in a similar manner. One of the commonest species is the hop aphid 



Figure 59.— European fruit lecanium. Twice natural size. 



