Figure 74. — Stone fly feeding on peach bud. X 2. 



66 CIRCULAR 2 7 0, U. S. DEPARTMENT OF AGRICULTURE 



peach trees in the Pacific Northwest, and the reader is referred to page M 

 53 for a discussion of this insect. ™ 



Stone Flies 



Stone flies or salmon flies (Taeniopteryx pacifica Banks) occasionally 

 injure the buds of peach, apricot, and plum trees in the spring (fig. 74), 

 particularly where 

 these trees are grow- 

 ing near the Colum- 

 bia River or some 

 other large stream. 

 The young of these 

 insects live in, the 

 streams, and the 

 adult flies emerge 

 early in the spring, 

 when thousands of 

 cast skins from which 

 the flies have emerged 

 may be found among 

 the rocks along the 

 stream banks. The 



flies feed on the fruit buds mostly during warm, sunny weather, 

 destroying many of the buds and injuring others so that they produce 

 deformed fruit. If control is necessary, lead arsenate, in the propor- 

 tion of 2 pounds to 100 gallons of water, should be effective if applied 

 as soon as the insects appear. 



NUT INSECTS 



Filbert Worm 



The filbert worm 6 (Melissopus latiferreanus (Wals.)) is the most 

 serious pest of filberts in western Oregon and Washington on account 

 of its direct injury to the nuts. It is generally distributed through- 

 out the Pacific Northwest, but causes commercial loss only locally. 

 This worm is the larva of a pale to dusky moth having two coppery 

 bands near the tips of its fore wings. Eggs are laid on the leaves 

 near the nuts, or on the husks, and the young worms enter the nuts 

 at the base. They mature after feeding for 3 or 4 weeks and leave 

 the nuts to overwinter in cocoons formed in the ground, in trash, 

 or in dried or rolled leaves on the ground. Pupation occurs from 

 early in May through August. No effective control measures have 

 been developed. 



Walnut Aphid 



The walnut aphid (Chromaphis juglandicola Kalt.) is the only 

 insect pest of any importance on walnut trees in the Pacific North- 

 west. It is a small pale-yellow, wingless or winged insect found on 

 the underside of the leaves, often in considerable numbers. These 

 aphids secrete a sticky liquid known as honeydew, which covers 

 the leaves and nuts, and in which a black fungus grows. Syrphus 

 flies, ladybeetles, and other natural enemies of aphids (p. 67) usually 



6 Also known as the Catalina cherry moth. 



