18 



and usually two or three, of the little grubs will be found at the ver}^ 

 heart of the growing tip, feeding upon the juices and completely check- 

 ing growth (fig. 8). If it is a runner that is attacked, it is destroyed; 

 if a fruit-bearing upright, the flower buds come out below the infested 



tip and no harm is done to 

 the crop. But the insects 

 continue to appear on the 

 bogs at intervals through- 

 out the season, and the 

 danger is that the late- 

 tipped uprights will form 

 no fruit buds for the next 

 year. 



The little grub is rather 

 a helpless sort of a crea- 



FiG. 7.— Cranberry tipworm; a, larva; b, breast bone; c, mouth ture, without legS and eVCU 

 parts-much enlarged (author's illustration). without distinct jaWS; but 



it has on the underside of the bod}- a little horny process or breast 

 bone by means of which it scrapes the plant tissue until the cells break 

 down and their contents may be absorbed. In about ten days it 

 reaches full growth, envelops itself in a thin, white, silken cocoon, 



Fig. 8. — Work of tipworm (author's illustration). 



and two or three days thereafter changes to an adult — a minute, two- 

 winged fly or midge whose wings when expanded measure less than an 

 eighth of an inch from tip to tip. The male is quite uniformly 

 3^ellowish-gray and inconspicuous, but the female has the abdomen 



