71 

 INSECTS ATTACKING THE CHERRY TREE. 

 " Sucking Insects." 

 I. The Cherry Black Fly, Myzus cerasi. Order Rhynchota. 



It is a very bad pest of the cherry and all the varieties, and is 

 especially bad on wall fruit. 



It destroys the leaves, and sometimes kills the young shoots. 



In early spring, wingless viviparous females appear on the lower 

 leaves, having hatched from eggs laid the previous autumn. 



They soon produce live young, which develop into wingless, vivi- 

 parous females, which soon spread over the tree, feeding on the leaves 

 from their undersides. 



The infested leaves, through their punctures, curl up, and many 

 die in the hot, dry weather. 



In July most of the aphides develop into olive-green pupas with 

 yellowish wing-cases. 



Later these develop into winged, viviparous females, and for a little 

 time they remain on the tree, and then suddenly leave it. 



Where they emigrate to is uncertain, but when they return they 

 give rise to the oviparous forms, the female of which is wingless, and 

 deposits from one to four eggs on the lower branches, trunk, or 

 suckers. 



Insecticides. — Spray in spring and autumn with 4 lb. of strong, 

 denatured tobacco to 10 gall, of water. 



Spray with caustic winter wash to keep the tree clean, and to 

 prevent any shelters for the eggs. 



Remove and burn all suckers that come up. 



" Biting Insects." 



I. The Cherry-tree Stem Borer, Semasia woeberiana. 

 Order Lepidoptera. 



This pest is destructive and is increasing, and it also attacks the 

 apple, plum, peach, nectarine, and almond. 



It bores through the bark into the sapwood. These borings may 

 be very smaU, but large cavities are formed in badly attacked trees, 

 being two to four inches deep and the same width, extending about 

 one to three feet in length. 



Trees thus infested are often attacked by fungi, the lower part of 

 the stem quickly rotting and dying. 



The first brood moths appear in May and June, when the female 

 deposits her eggs in crevices in the bark, usually near the ground. 



The larvae emerge in a week, and at once commence to feed on 

 the bark, boring beneath it and forming irregular cavities by eating the 

 inner bark and sapwood, and often penetrating four inches. Their 

 presence can be easily recognized by the sawdust around the hole they 

 have excavated. Exudations of gum are also seen on the tree, and 

 fungi often attack the exposed parts of the stem and roots. The I'arvse 



