THE CANADIAN ENTOMOLOGIST. 



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contain from one to four orange colored lice, many very minute shining, 



oval, whitish eggs, and usually 

 a considerable number of 

 young lice, not much larger 

 than the eggs and of the same 

 whitish color. Soon the gall 

 becomes over-populated, and 

 the surplus lice wander off 

 through its partly opened 

 mouth on the upper side of 

 the leaf, and establish them- 

 selves either on the same leaf 

 or on adjoining young leaves, 

 where the irritation occasioned 

 by their punctures causes the 

 Fig. 14. formation of new galls, vvithin 



which the lice remain. After a time the older lice die, and the galls which 

 they have inhabited open out and gradually become flattened and almost 

 obliterated ; hence it may thus happen that the galls on the older leaves 

 on a vine will be empty, while those on the younger ones are swarming 

 with occupants. 



These galls are very common on the Clinton grape and other varieties 

 of the same type, and are also found to a greater or less extent on most 

 other cultivated sorts. They sometimes occur in such abundance as to 

 cause the leaves to turn brown and drop to the ground, and instances are 

 recorded where many vines have been defoliated from this cause. The 

 number of eggs in a single gall will vary from fifty to four or five hundred, 

 according to the size of it ; there are several generations of the lice during 

 the season, and they continue to extend the sphere of their operations 

 during the greater part of the summer. Late in the season, as the leaves 

 become less succulent, the lice seek other quarters and many of them find 

 their way to the roots of the vines, and there establish themselves on the 

 smaller rootlets. By the end of September the galls are usually deserted. 

 In figure 15 we have this type of the insect illustrated ; a shows a front 

 view of the young louse, and b a back view of the same ; c the egg, d a 

 section of one of the galls, e a swollen tendril ; / g, h, mature egg-bearing 

 gall lice, lateral, dorsal and ventral views ; /, antenna, and / the two- 

 jointed tarsus. 



