ECONOMIC ENTOMOLOGY. 



resembling those made on the roots. In such a case the 

 vine loses its leaves prematurely. Usually, however, the 

 natural enemies of the louse seriously reduce its numbers 

 by the time the vine ceases its growth in the fall, and the 

 few remaining lice, finding no more succulent and suitable 

 leaves, seek the roots. Thus, by the end of September the 

 galls are mostly deserted, and those which are left are 

 almost always infested with mildew, and eventually turn 

 brown and decay. On the roots, the young lice attach 

 themselves singly or in little groups, and thus hiber- 

 nate. The male gall louse has never been seen, and there 

 is every reason to believe that he has no existence. Nor 

 does the female ever acquire wings. It is but a transient 

 state, not at all essential to the perpetuation of the species, 

 and does, compared with the other type, but trifling damage. 

 As already indicated, the autumnal individuals of Gallicola 

 descend to the roots, and there hibernate. There is every 

 reason to believe also that, throughout the summer, some of 

 the young lice hatched in the galls are passing on the roots; 

 as considering their size, they are great travelers, and show 

 a -strong disposition to reach the earth with ease and safety. 

 At all events, we know from experiments, that the young 

 Gallicola, if confined to vines on which they do not normally 

 form galls, will, in the middle of summer, make themselves 

 perfectly at home on the roots. 



THE ROOT INHABITING TYPE. 



(Hadiciola.) 



We have seen that, in all probability, gallicola exists 

 only in the wingless, shagreened, non tubercled, fecund 

 female form. Radiciola, however, presents itself in two 

 principal forms. The newly hatched larvse of thi3 type are 



