EXPERIMENT STATION BUfJ.ETINS. 



315 



INSECTS AFFECTING THE BARK. 



European Fruit-scale (see Insects affecting the plum). 

 Oyster-shell Bark-louse (see Insects affecting the apple). 

 San Jose Scale (see Insects affecting the peach). 



INSECTS AFFECTING THE FOLIAGE. 



The Four-lined Leaf-bug. (Pwcilocapsus Uneatus.) 



Shortly after the leaves appear on our currant and gooseberry bushes, we 

 sometimes find small, wingless, scarlet bugs of a rounded form, and very active 

 in their habits, running about and hiding away under the leaves, which become 

 curled in consequence of their attack. These little bugs belong to the family, 

 of leaf-bugs, and later develop into winged forms of a black and yellow color. 

 During all the stages, these bugs feed on the juices of plants, drawing them 

 from beneath the surfaces of the leaves by means of long sharp beaks. The 

 effect on the foliage is first to cause it to curl, and later to kill a little patch 

 of the leaf substance about each point where the beak has been inserted. Such 

 leaves appear spotted, the injured dots losing color and becoming brown. The 

 adult bug is about five-sixteenth of an inch long, bright yellow, with four longi- 

 tudinal, black stripes running about two-thirds of the way down the back. The 

 winter is passed in the egg stage, in a slit cut in the side of a twig, usually not 

 far from the tip. Several eggs are thus placed in a row. In the spring, the 

 eggs hatch and tiny red bugs appear, which grow larger and larger by successive 

 molts until finally the adult stage is reached, this stage being yellow and black 

 in color. 



Fig. 35. — Four-lined Leaf-bug, after Davis. 



BEMEDIES. 



After these creatures become full grown and acquire wings, they are very 

 difficult to control by any methods at our command, but while still immature 

 and before they change from the red coat to the yellow and black one, they 

 may readily be killed by a spray of kerosene-emulsion forcibly applied. This is 

 best done with a nozzle set at right angles to the hose. Such an arrangement 

 is easily prepared by using an elbow just behind the nozzle. With such a nozzle, 

 one can spray upward from beneath, and that very forcibly and economically 

 if a good nozzle be selected. Watch out for the bugs just as soon as the leaves 

 expand, and kill them early. Use kerosene-emulsion, tobacco-water or some 

 other good contact insecticide. When doing winter pruning, remove and burn 

 all of the material which is cut out. 



