Packard.] 



IJSrSEOTS OF THE FIELD. 



207 



passed into Iowa, and in 18G4 and 1865 it crossed tlie Mis- 

 sissippi, a thing whicli never ought to have been allowed. 

 It invaded Illinois on its western border, crossing over from 

 northeastern Missouri and Iowa. Mr. Walsh predicted that 

 it would advance eastward at the rate of fifty miles a year. 

 In 1868 it appeared in Ohio. Mr. Riley states that its aver- 

 age annual progress towards the east has been upwards of 

 seventy miles. "At the same rate of progression it Avill 

 touch the Atlantic Ocean in about ten years from now, or 

 A.D. 1878."* But in fact it has travelled faster than that, 

 and the year 1876 will witness the arrival of this pilgrim 

 from the west in the potato patches of the descendants of 

 the Pilgrim Fathers. 



This beetle belongs to the family of leaf-eating Coleoptera 

 (or Chrysomelidse) of which the common striped squash 

 Fig. 153. Fig. 154. 



Doryphora juncta. 



D. 10-lincata. 



beetle is a familiar example. It lays its eggs on the leaves 

 of the plant it inhabits in the larva, or grub, and the adult 

 state ; while in the pupal, or inactive, period of its existence 

 it lives in the ground, just under the surface of the soil. 

 Figure 153, from Riley, gives an idea of Doryphora juncta, an 

 ally of this insect, in its different stages. All the draw- 

 ings are of the size of life except d, a wing cover, and e, 

 representing a leg enlarged ; a represents the yellowish 



♦First Annual Report on the Noxious and Beneficial Insects of Missouri, 

 1869. p. 102. 



15 



