THE AMERICAN ENTOMOLOGIST. 



17 



a wild species of Solanuin (vS. rostratuni), 

 a plant allied to and belonging to the same 

 genus as the cultivated Potato {Solanum 

 tuberosum). The pioneers on the western 

 plains and prairies little imagined that they 

 were in such close proximity to an insect 

 that would soon give them an immense 

 amount of trouble, and make the culti- 

 vation of the Potato anything but a pleas- 

 ant or profitable occupation. But in 1861, 

 Mr. Thos. Murphy of Atchison, Kansas, 

 reported that they were so numerous in his 

 garden that he was enabled in a very short 

 time to gather two bushels of them. His 

 Potatoes were quickly destroyed, and the 

 beetles then spread in all directions. In 

 the same year they appeared in other parts 

 of Iowa, and from there passed eastward, 



[Fig. 44.] 



the few scattering plants of the wild Sola- 

 num, as found on the plains, its numbers 

 were limited to a few thousands, or per- 

 haps hundreds to the square mile ; but as 

 an acre of Potatoes will probably furnish 

 more food than all the wild plants on a 

 hundred of prairie, the sudden increase of 

 this pest when it reached the out-lying 

 settlements or farms of Kansas, Nebraska 

 and Iowa, can readily be accounted for. 



At first the progress of the beetles east- 

 ward was at the rate of about sixty or 

 seventy-five miles annually, but as they 

 reached the more thickly settled regions 

 their progress was more rapid, probably 

 receiving some assistance from the rail- 

 roads, specimens flying into the cars at 

 station and escaping at 

 another a hundred or two 

 miles eastward, or in what- 

 ever direction the train 

 may have been going. That 

 the beetles were in many 

 instances scattered over 

 the country by such means 

 can scarcely be questioned, 

 as they were frequently 

 found in the cars that had 

 passed through infested 

 regions. 



EASILY CONFOUNDED WITH 

 AN ALLIED SPECIES. 



some western 



Colorado Potato-beetle 

 <:, pupa; ^, (/, beetle, back and side view: 

 punctation ; y", leg — enlarged (after Riley). 



crossing the Mississippi River in 1864, ap- 

 pearing in several localities almost sim- 

 ultaneously within the State of Illinois. 

 In stating that this insect passes from one 

 locality to another, it must not be under- 

 stood that it migrates, it merely spreads, 

 enough remaining behind to keep up an 

 abundant stock, and they are probably no 

 less abundant on the western plains at this 

 time than when first discovered there by 

 Mr. Say, sixty years ago. The sudden 

 and enormous increase in numbers, as 

 noted in Kansas and Iowa, was wholly due 

 to the increase in the supply of food, for 

 so long as this insect had to depend upon 



different stages of growth ; ,, 



left wing-cover, showing WCll 



This beetle is now too 

 known to need de- 

 scription, but it may be 

 well to note that there is a closely allied 

 species (Z>. juncta, Germar,) that is fre- 

 quently confounded with the genuine " ten- 

 liner," although it never attacks the Potato, 

 but feeds upon various species of wild Sola- 

 num, but especially the Horse-nettle {Sola- 

 num carolinense), a very common weed, es- 

 pecially in the Middle and Southern States. 

 Both the larva and mature insect of 

 this Bogus Potato-beetle resemble the 

 genuine ; but upon a close examination, a 

 very marked difference may be discovered. 

 The most prominent distinctive character- 

 istics observed in the nearly mature larvae 

 are as follow : In the true or D. lo-lineata 



