194 NEBRASKA STATE HORTICULTURAL SOCIETY. 



ing upon the hinder part of her back which is easily detached. 

 Daring the summer the insects are wingless, and the young are pro- 

 duced alive, but about the middle of October, among the wingless 

 specimens appear a considerable number with wings, and these have 

 but little of the downy substance upon their bodies, which are nearly 

 black and rather plump. The fore wings are large and about twice 

 as long as the narrower hind wings. Late in the autumn the female* 

 deposit eggs for another generation the following spring, a fact which 

 should induce fruit growers to take particular pains to destroy these 

 lice wherever found, for the colony that is permitted to establish itself 

 upon some worthless tree, or on the shoots or suckers at its base, will 

 furnish the parents of countless hosts that may establish themselves 

 next year on the choicest trees in the orchard. The insects are ex- 

 tremely hardy and will endure a considerable amount of frost, and it 

 is quite probable that some of them survive the winter in the perfect 

 state in the cracks of the bark of the trees. 



" The eggs are so small that they require a magnifying glass to en- 

 able one to see them, and are deposited in the crevices of the bark at 

 or near the surface of the ground, especially about the base of suckers, 

 where such are permitted to grow. 



"The young, when first hatched, are covered with very fine down, 

 and appear in the spring of the year like little specks of mold on the 

 trees. As the season advances, and the insect increases in size, its 

 cottony coating becomes more distinct, the fibres increasing in length 

 and apparently issuing from all the pores of the skin of the abdomen. 

 This coating is very easily removed, adhering to the fingers when 

 touched. Both young and old derive their nourishment from the sap 

 of the tree, and the constant punctures they make give rise to warts 

 and excrescences on the bark, and openings in it, and, where very nu- 

 merous, the limbs attacked become sickly, the leaves turn yellow and 

 drop off, and sometimes the tree dies." 



This louse was noticed as early as 1848, at which time it was found 

 upon thousands of small trees in such large numbers that the destruc- 

 tion of the trees was necessary. Since that time it has been gradually 

 spreading over the country until it has become quite general save in 

 isolated localities. 



