96 INSECTS INJURIOUS TO VEGETATION. 



of the potato-vines, having at that time recently come out of the 

 ground, where they pass the winter in the pupa state. They eat 

 the leaves of the potato, gnawing irregular holes through them ; 

 and, in the course of a few days, begin to lay their oblong oval 

 golden yellow eggs, which are glued to the leaves, in parcels of 

 six or eight together. The grubs, which are hatched in about a 

 fortnight afterwards, are of a dirty yellowish or ashen white color, 

 with a darker colored head, and two dark spots on the top of the 

 first ring. They are rather short, approaching to a cylindrical 

 form, but thickest in the middle, and have six legs, arranged in 

 pairs beneath the first three rings. After making a hearty meal 

 upon the leaves of the potato, they cover themselves with their 

 own filth. The vent is situated on the upper side of the last 

 ring, so that their dung falls upon their backs, and, by motions 

 of the body made for this purpose, is pushed forwards, as fast as 

 it accumulates, towards the head, until the whole of the back is ^ 

 entirely coated with it. This covering shelters their soft and ten- 

 der bodies from the heat of the sun, and probably serves to secure 

 them from the attacks of their enemies. When it becomes too 

 heavy or too dry, it is thrown off, but replaced again by a fresh 

 coat in the course of a few hours. In eating, the grubs move 

 backwards, never devouring the portion of the leaf immediately 

 before the head, but that which lies under it. Their numbers are 

 sometimes very great, and the leaves are then covered and nearly 

 consumed by these filthy insects. When about fifteen days old 

 they throw off their loads, creep down the plant, and bury them- 

 selves in the ground. Here each one forms for itself a little cell 

 of earth cemented and varnished within by a gummy fluid dis- 

 charged from its mouth, and when this is done, it changes to a 

 pupa. In about a fortnight more the insect throws oft' its pupa 

 skin, breaks open its earthen cell, and crawls out of the ground. 

 The beetles come out towards the end of July or early in August, 

 and lay their eggs for a second brood of grubs. The latter come 

 to their growth and go into the ground in the autumn, and remain 

 there in the pupa form during the winter. 



The only method that occurs to me, by means of which we 

 may get rid of these insects, when they are so numerous as to be 

 seriously injurious to plants, is to brush them from the leaves into 

 shallow vessels, containing a little salt and water or vinegar. 



