GYPSY MOTH 



2649 



GYROSCOPE 



'HE GYPSY MOT 



r _ , Male 

 Female p upa 

 Pupa 



Female Moth 



Male Moth 



Full Grown Caterpillar 



Female Moth Laying Eggs 



Egg Mass 



A full-grown caterpillar is about two or two 

 and a half inches long, with a double row of 

 warts on its back. Eight at the end of the 

 body are blue, twelve are red; and four blue 

 ones are behind the head. Similar warts occur 

 on the sides. In midsummer the caterpillars 

 go to sheltered places and spin about them- 

 selves loose cocoons. In this silky shelter 

 they pupate and in two weeks the moths come 

 forth. 



The most effective way to fight this pest is 

 by careful collection and burning of egg-masses. 

 This can be done between August and May. 

 A fire run over the ground will not always kill 

 the eggs, however. Burning them in a stove 

 is the surest way. The eggs can also be killed 

 by applying the following mixture to the 

 masses: Creosote oil, 50 per cent; carbolic 

 acid, 20 per cent; spirits of turpentine, 20 per 

 cent, and 10 per cent of coal tar to color the 

 mixture to show which clusters have been 

 treated. 



Large numbers of caterpillars can be caught 

 by banding infested trees with burlap or other 

 coarse cloth. The caterpillars hide during the 

 day and many will choose the fold of the band 

 as shelter; they can then be removed and 

 killed. Spraying trees with arsenate of lead, 

 using ten pounds to one hundred gallons of 

 water, will destroy them, if the work is done in 

 May and June while the creatures are still 

 young. M.S. 



The United States Department of Agriculture 

 has issued a Bulletin (No. 11) on the extermina- 

 tion of the gypsy moth, which may be had on re- 

 quest. 



Related Subjects. The reader is referred to 

 the following articles in these volumes: 

 Brown-tail Moth Insecticides and 



Caterpillar Fungicides 



Cocoon Moth 



Insects 



GYROSCOPE, ji'roskope, a mechanical ap- 

 paratus that demonstrates the principles of 

 rotation and equilibrium of bodies in motion, 

 the center of gravity and centrifugal force. 

 In form a gyroscope consists of a circular disk 

 with a heavy rim. It is mounted upon an 

 axis in a way in which it can revolve with the 

 least possible resistance. In turn, this axis 

 is also mounted in a direction at right angles 

 to that of the disk. 



Fig. 1 illustrates the gyroscope in its simplest 

 form. The wheel is heavy and firmly secured 

 to its shaft. The outer ring is equipped with 

 bearings carrying the shaft and allowing it to 

 turn freely. This arrangement of simple parts 

 exhibits none of the characteristic features of 

 the gyroscope until the wheel is made to 

 rotate. The toy machine must be rotated by 

 an unwinding string, as shown in the illustra- 

 tion. Then some of the seemingly impossible 

 things of which the machine is capable become 

 apparent. So long as the wheel is kept in 

 rapid motion the gyroscope resists any change 



