96 



IKJURIOUS INSECTS 



when first discovered there by Mr. Say, oyer 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 the few scattering plants of the wild Sola- 

 num, as found on the plains, its numbers were limited 

 to a few thousands, or perhaps hundreds to the square 

 mile; but as a single acre of potatoes will probably furnish 

 more food than all the wild plants on a hundi-ed acres 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. A few years ago, 

 their ravages in Nebraska and Kansas were severe. 

 Since then the bugs have not caused much damage 

 west of the Missouri. 



At first the progress of the beetles eastward 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 recei^^ng some assist- 

 ance from the railroads, specimens flying into the cars at 

 some western station and escaping at another a hundred 

 or two miles eastward, or in whatever direction the train 

 may have been going. 



NATURAL HISTOEY AND TRANSFOEMATIONS. 



Prof. Riley was the first to make known the natural his- 

 tory and transformations of the Potato-beetle. They may 

 be briefly summed up as follows: The female beetle depos- 

 its her eggs on the underside of the leaves, in clusters of a 

 dozen, up to fifty or more. The eggs are of an orange 

 color, and hatch in about a week after being laid, the 

 grubs immediately commencing to feed and continumg 

 until mature, which occurs in from fourteen to eighteen 

 days, varying somewhat as the weather may be favorable 



