36 



This insect is an imported bark louse, superficially resembling the 

 " mealy bug," and is commonly noticed in the crevices of the bark 

 on the trunks and branches of elms. The females are bordered 

 with a mass of whitish wax and give birth to large numbers of 

 young during the early part of July. The young lice migrate to the 

 leaves and after feeding on the plant juices throughout the summer, 

 return to the branches with the approach of cold weather and pre- 

 pare to hibernate. According to Prof. L. O. Howard, the males 

 appear late in May and the females give birth to the young in 

 from three to four weeks from the time of pairing. 



Food Plants and Damage. 

 This bark louse was probably brought to this country upon Eu- 

 ropean elms. It occurs commonly on the Camperdowu and Scotch 

 elms and also inflicts serious injury to the American elm, the slip- 



Fio. 5. The Elm Bark Louse. <;, adult female from below; /y, adult female from nide; 

 <•, adult female from above — all greatly eularged; (/, empty wax cuHhion; c, females in 

 natural poMition — enlarged; ./', Bhrivelled females, natural size. (From " Insect Life.") 



pery elm and the cork elm. The greatest damage to elms from 

 this insect occurs on young trees recently taken from the nursery. 

 As factors in the dissemination of this insect, nurseries have played 

 a most important part. In fact, the first complaint of damage 

 from the elm bark louse was reported from a large nursery in New 

 York. Where large numbers of elms are grown in compact plots 



