181 



PLANT LICE OR APHIDS.' 



H. T. FERNALD, PH.D., STATE KURSERT IKSPECTOR, AMHERST, MASS. 



There are more thaii three hundred kinds of plant lice 

 known in this country, feeding on nearly all our common 

 plants, ishrubs and trees, 

 and the injury they 

 cause is often serious. 

 They begin their work 

 early in spring, often 

 before the plants they 

 are upon have gotten 

 well started, and, in- 

 creasing in numbers 

 with great rapidity, do 

 a great deal of damage 

 almost before it is real- 

 ized that they are pres- 

 ent. 



Among the more im- 

 portant plant lice which 

 concern the fruit grower 

 and farmer are the 

 woolly apple louse, so 

 noticeable along scars of 

 the limbs of apple trees in the fall, because of the white 

 woolly threads it forms ; the green apple louse ; the black 

 louse on plum and cherry ; the cabbage louse ; the currant 

 louse; the rose louse; the pea-vine louse; and during the 

 spring of 1903 the elm louse and maple louse. 



The life history of some species of these insects is quite 



Twig of apple, showing plant 

 natural size.) 



(Ab.iVit 



I Nature Leaflet No. 18, Nov. 1, 190G. 



