INSECTS. Ill 



striking colour, and always with dark spots. The 

 beetles eat leaves ; the larvae feed upon parts of the 

 same plants, sometimes living outside upon the leaves, 

 or it may be excavating channels in the inside of a 

 leaf or of the stem. Most leaf beetles lay many eggs, 

 and in many species there are several generations 

 annually. The plants attacked by them are often 

 stripped quite bare. Here belongs the blue Alder 

 Leaf Beetle (Galeruca alni), the Poplar Beetles (Chry- 

 someli populi and C. tremulce), the Asparagus Beetles 

 {Grioceris merdigera and C. duodeciinpunctata), etc. 

 Of species injurious agriculturally, I will first mention 

 the Colorado or PotatoBeetle (Ohrysomeladecemlineata). 

 This beetle originally lived in the 

 west of the United States on wild 

 solanaceous plants; but as soon as 

 potato culture extended to the west 

 the beetles also attacked potato plants. 

 As soon as the insects had spread to 

 this plant they began to appear in 

 great numbers owing to their very „ „, „ , , 



o /» 1 I • T ^^^- ^^- — Potato 



great powers oi reproduction ; and Beetle iairysomda 

 they quickly spread from one field to *=«'»««««»)■ 

 another, always going further and further east. 1859 

 was the first year when they became notorious as 

 pests, and, since they first appeared as such in the 

 State of Colorado, the insect received the name 

 "Colorado Beetle." In a short time the beetles 

 spread to the east, especially to places where potato 

 culture was carried on; in 1865 they crossed the Mis- 

 sissippi, and in 1870 they were already spread over 

 the states of Indiana, Ohio, Pennsylvania, Massa- 

 chusetts, and New York. They were soon found in all 

 the eastern states, and European farmers began to be 

 alarmed. In most of the countries of Europe police 

 regulations were made for the purpose of preventing 

 the introduction of the unbidden guests. Colorado 

 beetles have indeed been brought several times to 



