180 INSECTS INJURIOUS TO VEGETATION. 



scribed ; — it measures about half an inch from the tip of the horn 

 to the end of the body ; the male is blackish above, with a long 

 yellow spot on each side of the back ; and the female is ash- 

 colored, and without spots. While on the trees, these insects, 

 though perfectly still, are not unemployed ; but puncture the bark 

 with their sharp and slender beaks, and imbibe the sap for nour- 

 ishment. The female also appears to commit her eggs to the 

 protection of the tree, being furnished with a piercer beneath the 

 extremity of her body, with which to make suitable perforations 

 in the branches. As I have never seen the young on these trees, 

 I presume that, as soon as they are hatched, they make their way 

 to the ground, and remain under the surface of the soil, sucking 

 the sap from the roots of plants, until they are about to enter 

 upon their last period of existence, when they crawl up the trunks 

 of the trees, throw off their coats, and appear in the perfect or 

 winged state. From the great numbers of these tree-hoppers 

 which exist in certain seasons, the locust-trees undoubtedly suffer 

 much, not only in consequence of the quantity of sap abstracted 

 from their branches, but from the numerous punctures made by 

 the insects in obtaining it and in laying their eggs. 



The oak-tree is attacked by another species, the white-lined 

 tree-hopper {M. univittata), which may be found upon it during 

 the month of July. It is about four tenths of an inch in length ; 

 the thorax is brown, has a short obtuse horn extending obliquely 

 upwards from its forepart, and there is a white hne on the back, 

 extending from the top of the horn to the hinder extremity. 



The common creeper {Ampelopsis quinqiiefolia*) is inhabited 

 by a tree-hopper, which has an oblong square and thin elevation 

 or crest on the middle of the thorax. Its body is usually of a 

 reddish ash-color, and the thorax is ornamented with three reddish 

 brown bands, one of: which is above the head and extends trans- 

 versely between the lateral projecting angles of the thorax, the 

 second is a short asd oblique line on each side of the front-part of 

 the crest, and the third is also oblique, and begins on the outer 

 edge of the thorax, and passes obliquely forwards on each side to 



* Some botanists have unwarrantably changed the specific name of this plant to 

 Hederacea. 



