TEE STATUE ENTOMOLOGIST. 87 



and good cultivation, would do away with it; while the latter main- 

 tained that the Phylloxera was the sole cause of the trouble. There 

 are, doubtless, certain conditions of soil which will prove favorable to 

 the increase of the louse, and it may also be influenced by the sea- 

 sons and by good or poor cultivation; but that this insect should be 

 found only on such roots as are already diseased is highly improbable, 

 and there can be no reasonable doubt that M. Lichtenstein is right in 

 attributing the disease directly to the Phylloxera. The appearance 

 of mites is the almost inevitable consequence of diseased and rotting 

 vegetation, but Plant-lice cannot live on such vegetation, and inva- 

 riably leave it as soon as they have, by their punctures, reduced the 

 healthy tissues to such a state. Moreover, the history of our louse, 

 which I shall now proceed to give, corroborates M. Lichtenstein's 

 views. 



In Missouri tkis insect has proved very injurious to the Clinton 

 vine for several years past — at least as far back as 1864, when the fo- 

 liage of the Clinton was reported, in the proceedings of our State Hor- 

 ticultural Society, as "very bad"— and Mr. Geo. Husmann informed me 

 that in 1S69, it actually defoliated three-fourths of an acre of Clin- 

 tons and Taylors on bottom land at Bluffton, though it did not appear 

 to do much injury on the hills. It was quite bad around Kirkwood 

 the present year, and, judging from reports, of correspondents and 

 from my own observations, it was more than usually abundant in most 

 of the Eastern States. 



In this latitude the first galls are noticed by about the middle of 

 May, and by the middle of June they begin to be quite common. It 

 occurs most abundantly on the Clinton and Taylor, but is also found 

 on the wild Frost Grape( V. cordifolia), and such other cultivated 

 varieties of it as Golden Clinton and Huntington ; also on the Dela- 

 aware, and early in the year I even found a few large galls on the 

 Concord. According to Dr. Morse it also occurs on the Iona, which is 

 a variety of the Northern Fox Grape ( V. labrusca). The galls vary 

 somewhat in appearance, according to the vine upon which they 

 occur, those I have noticed on the wild Frost Grape being more 

 hirsute than those on the cultivated Clinton, and these again rougher 

 than on the Taylor. 



The few individuals which start the race early in the year station 

 themselves upon the upper side of the leaves, and by constant suc- 

 tion and irritation soon cause the leaf to swell irregularly on the op- 

 posite side, while the upper part of the leaf gradually becomes fuzzy 

 and closes, so that the louse at last sinks from view, and is snugly set- 

 tled in her gall. Here she commences depositing, her bulk increasing 

 during pregnancy. Eventually she grows to be very plump and 

 swollen, acquires a deep yellow or orange tint, and crowds the space 

 within the gall with her small yellow eggs, numbering from fifty to 

 four or five hundred, according to the size of the gall. The young 

 lice are pale yellow, and appear as at Figure 40, cZ, e. As soon as 



