44 INSECTS AFFECTING VEGETATION 



early in their career. Sometimes more than one application is neces- 

 sary, but be sure to hit each bud with the spray. The presence or ab- 

 sence of the little nests later will indicate the success or failure of the 

 application. (Bui. 45 Conn. Exp. Sta.; Bui. 24 Mich. Agr. Exp. 

 Sta.) 



The Buffalo Tree-Hopper. A small green insect, three-eighths 

 of an inch in length, triangular in form, and shaped somewhat like 

 a beechnut, but having the prothorax extending above the head in 

 two horn-like growths. They sometimes weaken the twigs of apple 

 by laying their eggs therein. The wounds so made are slow to heal, 

 and on young trees may be the cause of injury through the breaking 

 off of the twigs. No remedy is known except the cutting out of the 

 eggs during the fall and winter. (Bui. 24 Mich. Agr. Exp. Sta.) 



The Plum Cureulio. (See Plum Insects). 



PEAR INSECTS. 



The European Pear Scale. This pest, which is commonly 

 known in California as the Italian pear scale, closely resembles to the 

 naked eye the San Jose scale (Aspidiotus perniciosus Comst.), but 

 can be readily distinguished from this species by the form of the 

 male scale which is a great deal longer and carinated. Furthermore 

 they can be separated by the manner of working. The European 

 pear scale, in California, probably works only under cover of the 

 lichens on the trunk and larger limbs, and apparently does not work 

 on the twigs or younger branches as does the San Jose scale. 



Distillate-oil emulsion at 6 per cent strength and crude-oil 

 emulsion at 12 per cent strength, measured by their efficiency against 

 scales and lichens, convenience of preparation and application, and 

 cost, are the sprays best adapted for the European pear scale. All 

 sprays, to insure the best results, should be applied with a power out- 

 fit at a high pressure (180 to 200 pounds). A coarse, drenching 

 spray applied with crook nozzles is preferable, and February is the 

 best month in which to spray. 



The Howard Scale. Individual insects are of very minute size, 

 being smaller than a pin head. They are of yellowish-orange color, 

 covered by a pale grayish scale secretion. For the greater part of the 

 insect's life it is motionless upon the bark or fruit. The winter is 

 passed in an immature stage. In the spring, winged males appear, 

 and early in the summer young insects are hatched from eggs laid 

 beneath the female scale covering. These crawl about for a short 

 time, finally settling down, the females to remain motionless for the 

 rest of their lives. 



Slightly infested trees will exhibit only inconspicuous grayish 

 dots. Badly infested trees have a grayish appearance over their 

 bark, much as if a layer of ashes covered the tree. When rubbed, 

 this gives the surface a greasy or buttery appearance, caused by the 

 crushing of the bodies of myriads of the yellow parasites hidden un- 

 der the scales. It is most common upon pear, prune, plum, and al- 

 mond. The Bartlett is the most susceptible variety of pear grown in 

 the Grand Valley. 



