ONE HUNDRED THOUSAND FACTS FOR THE PEOPLE. 403 



44, c) to tell the tale of the futile effort. 

 Otherwise, in a few days the gall if formed, 

 and the inheld louse, which while eating 

 its way into house and home, was also 

 growing apace, begins a parthenogenetic 

 maternity by the deposition of fertile eggs, 

 as her immediate parent had done before. 

 She increases in bulk with pregnancy, 

 and one egg follows another in quick 

 succession, until the gall is crowded. 

 The mother dies and shrivels, and the 

 young, as they hatch, issue and found 

 new galls. This process continues 

 during the summer until the fifth or 

 sixth generation. Every egg brings 

 forth a fertile female, which soon be- 

 comes wonderfully prolific. The 

 number of eggs found in a single gall 

 averages about 200; yet it will some- 

 times reach as many as 500, and, if 

 Dr. Shimer's observations can be re- 

 lied on, it may even reach 5,000. As 

 summer advances, they do frequently 

 become prodigiously multiplied, com- 

 pletely covering the leaves with their 



all species of the grape-vine cultivated in 

 the Eastern and Middle States, and on 

 the wild cordifolia ; but it flourishes only 

 on the river-bank grape, and more espe- 

 cially on the Clinton and Taylor, with 

 their close allies. 

 As already indicated, the autumnal in- 



f ^ ' & h 



Fig. 44. — Type Galuecola. 

 b, newly-hatched larva, ventral and dorsal view ; 



x .. J , °. , . a, 6, newly-hatched larva, ventral and dorsal view ; c, 



galls, and Settling on the tendrils, eg g ; d, section of gall; e, swelling of tendril; f,g, h, 

 leaf- stalks, and tender branches, mother gall-louse— lateral, dorsal and ventral views ; i, 

 where they also form knots and her antenna ; J, her two-jointed tarsus. Natural sizes in- 

 rounded excresences Fig. 44), much dM * ted at sides - 

 resembling those made on the roots. In dividuals of galltzcola descend to the roots, 



and there hibernate. There is every rea- 

 son to believe also that, throughout the 



such a case, the vine loses its leaf prema- 

 turely. 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 Sep- 

 tember, the galls are mostly deserted, 

 and those which are left are almost 

 always infested with mildew (Bottytis 

 viticola, Berkely), and eventually turn 

 brown and decay. On the roots, the 

 young lice attach themselves singly 

 or in little groups, and thus hibernate. 

 The male gall-louse has never been 

 seen, and there is every reason to be- 

 lieve he has no existence. Nor does 

 the female ever acquire wings. In- 

 deed, we cannot lay too much stress 

 on the fact that gallxcola occurs only 



Fig. 45. — Type Radicicola. 



a, roots of Clinton vine, showing relation of swellings 

 v»* "»v- wv* m»v i »»«-n'»u. uv-vuij vui; to leaf-galls, and power of resisting decomposition; b, 

 as an agamic ana apterous lemaie larva as it a pp ea rs when hibernating ; c, d, antenna and 

 form. It is but a transient summer leg of same; e,f,g, forms of more mature lice; £, gran- 

 State, not at all essential to the per- ulations of skin; *', tubercle; /, transverse folds at bor- 



petuation of the species, and does, der of J oints '> *> simple eyes. 



compared with the other type, but trifling 1 summer, some of the young lice hatched 



damage. We have found it occasionally on | in the galls are passing on to the roots; 



