MORE ABOUT THE GRAPE-VINE PEST. 



163 



nella), especially certain small dark-brown species belonging to the 

 genus Sci/mntis, and whose young, thickly covered with white and 

 evenly-shorn tufts of a cottony secretion, are frequently found at their 

 good work within the galls. Following these may be mentioned, as 

 auxiliaries, certain Syrphus-fly larvae, which, being blind, go groping 

 about among the eggs and young lice, which they seize and suck to 



Fig. 6. 



Fig. 5. 



Strphus Fly. 



Insidious Flower-Bug. 



death. Also certain orange larvae of a smaller two-winged fly [Xeu- 

 copis) ; a few genuine bugs {Heteroptera), and notably the Insidious 

 Flower-bug (Afit/iocoris insidlosiis, Say, Fig. 6), and certain smaller 

 Hymenopterous parasites. 



The enemies known to attack the Phylloxera underground are, 

 naturally enough, fewer in number. In one instance I have found a 

 Scymnus larva at the work six inches below the surface, and there is 

 a Syrphus fly [Plpiza radicum^ W. and R., Fig. 7) whose larva lies 

 underground and feeds both on the apple-tree-root louse, and on this 



Fig. 7. 



Root-louse Strphus Flt.— a, larva ; t, pupa ; 



grape-root louse. Wonderful indeed is the instinct which teaches the 

 blind larva to penetrate the soil in search of its prey ; for the egg 

 must necessarily be laid at th? surface. But, though the underground 

 enemies of its own class are few, I have discovered a mite which preys 

 upon this root-inhabiting type, and which renders efticient aid in keep- 



