INSECTS, HARMFUL AND OTHERWISE 219 



mealy bugs, a species of scale. On many fruit and other 

 trees there often form dense incrustations of scale insects that 

 sometimes kill the trees. The apple-bark louse is such a one. 

 The San Jose scale, that affects the orange and many other 

 fruit trees, has done a vast amount of damage. The best 

 remedy for such insects is spraying with emulsion. Fumi- 

 gation with hydrocyanic acid gas is also used. 



Another serious menace to all orchards is the Bark and 

 Wood Borers. These are the larvae of various moths and 

 beetles, that gnaw their way through and live upon the tissues 

 of the bark and wood of stems and roots. Apple and other 

 fruit trees, the box-elder, basswood, and many other trees will 

 show upon their bark many holes. These were mostly made 

 by woodpeckers digging for borers. With a strong knife 

 or other tool chip the bark from some old box-elder tree, 

 and you will no doubt find some bark borers that have made 

 tunnels between the bark and the wood. On peach and 

 cherry trees there may be fresh masses of exuding gum, which 

 indicates the presence of borers, and cutting into the bark will 

 reveal the larvae. The best remedy we have against these 

 borers is perhaps the woodpeckers, which should be en- 

 couraged in every orchard. Wrapping the trees is some- 

 times an effective remedy. 



The Codling-moth ravages apple orchards. Soon after 

 the petals fall from the flower the moth lays her eggs in the 

 calyx of the flower or, rather, young fruit. The larva that 

 hatches out bores its way into the core of the apple. The 

 affected apples fall early, and the grub bores its way out and 

 generally crawls up the trunk of the tree, to make its cocoon 

 under the bark scales. A second brood generally affects the 

 orchard again later in the summer and causes many apples 



