272 LANDSCAPE GARDENING. 



ELM-SCALE (Gossyparia ulmi), Fig. 155. Very little 

 seems to be known about the life -hi story of this insect, and 

 yet it is one of the most widely distributed and injurious 

 insects attacking the elm. It is a small, soft scale insect of 

 a whitish color (/) that attacks both the American and 

 European species of the elm. It is fonnd on tlie under side 

 of the branches, and when crushed leaves -a stain on the 

 fingers or clothing much like that of iron-rust. It injures 

 the trees by sucking the juices of the young shoots and 

 small branches. In many sections in Massachusetts they 

 were so abundant during the season of 1895 that the 

 leaves and bark of almost every tree were badly covered with 

 a black substance resulting from the dust of the atmosphere 

 adhering to the sticky exudations made by the insects 

 deposited upon them, arid from a black fungous growth 

 similar to that found in the exudations of the pear-tree 

 Psylla in our pear orchards. The leaves were also of a 

 sickly yellow color and the trees made a very small growth. 



Remedy. It has been found to be destroyed by the kero- 

 sene emulsion, applied thoroughly at the time when the 

 young are hatching out and moving from near the parent 

 scale to other parts of the tree for permanent location, and 

 again from five to ten days later. By close attention about 

 June 1st the best time can be easily determined. 



MAPLE-BORER (Plagionotus spcciosus), Fig. 156. In 

 most sections where the sugar-maple thrives this insect is 

 more or less injurious, though it is said to sometimes attack 

 other species. It is a very dangerous insect enemy, because its 

 work is difficult to detect until serious harm has been done. 

 The perfect insect is a beetle nearly an inch long, the head 

 is yellow, the thorax black, with transverse yellowish spots, 

 and the wing-covers are yellow and black. The beetles 



