Insects and Fungi Attacking Trees, Etc. 331 



sene emulsion, applied thoroughly at the time when the 

 young are being produced 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 ist the best time can be easily determined. The lime 

 sulphur solution used at the rate of i gallon to 50 of water 

 will probably also destroy it. 



Maple-borer {Plagionotus speciosus), Fig. 179. — In most 

 sections where the sugar-maple thrives this insect is more 

 or less injurious, though it is said to sometimes attack 



Fig. 179. — Maple-borer. 

 (Saunders: 5th Report U. S. Ent. Com., p. 375, Fig. 137.) 



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 

 appear in July and August, and lay their eggs on the bark 

 during the latter part of the last-named month. The eggs 

 soon hatch and the larvae or young work a short distance 

 under the surface of the bark, the first season throwing out 

 chips and droppings from their holes. If not molested, 

 the following season they go on feeding and working deeper 

 through the bark and sapwood, making a tortuous burrow 



