216 INSECTS INJURIOUS TO THE CHERRY. 



rest, is broad and flat, the outer edge of the fore wings being 

 rounded towards the base, and straight from the middle to 

 the tip, and when its wings are spread (see Fig. 222) it meas- 

 ures from three-quarters of an inch to an 

 FIG. 222. . - * 



inch across, ine tore wings are crossed by 



irregular wavy bands, alternately of bright 

 ochre-yellow and pale, dull, leaden blue ; 

 the yellow bands are varied with darker 

 spots, the most -conspicuous one of which is placed on the 

 outer margin near the tip, and from this spot a broader ochre- 

 yellow band extends towards the hind margin, and curves 

 thence to the inner angle ; the hind wings and entire under 

 surface are pale ochre-yellow. 



Where this insect is found to be injurious, the webs con- 

 taining the larva? and chrysalids should be gathered and 

 destroyed before the winged moths mature. 



No. 115. The Cherry-tree Plant-louse. 



Myzus cerasi (Fabr.). 



This black, disgusting-looking louse begins to appear on the 

 leaves of the cultivated cherry almost as soon as they are ex- 

 panded, being hatched from eggs deposited on the branches 

 the previous autumn, and they multiply so fast that the under 

 side of the young foliage is soon almost entirely covered with 

 them, and the growth of the tree stunted by their continual 

 appropriation of its juices. They crowd together in dense 

 masses, often two deep, standing on each other's backs, with 

 only sufficient space between to enable them to insert their 

 extended beaks into the leaves. In a few days these insects 

 multiply enormously, their black bodies covering not only the 

 under side of the leaves but also the leaf-stalks, and cluster- 

 ing about the stems and green heads of the young fruit, while 

 swarms of flies and other insects, attracted by the sweet exu- 

 dations from the bodies of the lice, keep up a constant hum 

 and buzz around the infested trees. 



The presence of these aphides in such numbers has the 



