COLEOrXERA. 105 



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 rinej. They are 

 rather short, approaehin£f to a cylindrical form, but thickest in 

 the middle, and have six legs, arranged in pairs l)cncath the 

 first three rings. After making a hearty meal upon the leaves 

 of the potato, they cover themselves Avith their own tilth. 

 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, 

 is pushed forwards, as. fast as it accinnulates, towards the 

 head, until the whole of the back is entirely coated with it. 

 This covering shelters their soft and tender 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 backwaMs, 

 never devouring the ])ortion 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 oft" their loads, creep down the plant, and 

 bury themselves in the ground. Here each one forms for itself 

 a little cell of earth, cemented and varnished within by a 

 gummy fluid discharged from its mouth, and when this is 

 done, it changes to a pupa. In about a fortnight more the 

 insect throws off 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 them, 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. 



The habits of the Hispas, little leaf-beetles, forming the 

 family Hispad.e, were first made known by me in the year 

 14 



