61 



Pnv(,i,nxKHA Mite, a, dorsal, 6. ventral view of female, 

 c, moiuti-parts , rf, /, <j, h, forms of tarsal appendages , e, 

 ventral tubercles of male. 



is the instiuet which teaches this Wind larva to penetrate the soil in search of its.prey ; for 

 the egg must necessarily be laid at the suif'acc. But though the underground enemies of its 

 own class are few, I have discovered a mite which preys extensively upon this root-inhabiting 

 type, and which renders efficient aid in keeping it in check in this country. This mite (Tyro 

 glyphus phi/lhm'ne, Planchon & Riley, Fig. 41},} belongs to the same genus as the cheese and 

 meal mites, and the species which infests preserved insects, and is such a pest in cabinets. At 

 is the rule with mites, it is born with but six legs, but acquires eight after the first or second 



moults. It varies considerably in ibrm, with age, 



and in studying it with a view of distinguishing 



it specifically from other described species, I 



have noticed all the different tarsal characters 



shown as </, /, g and h, (Fig. 46). and on which 



distinct genera have been founded. Mites pre- 



.sent themselves in such different forms that the 



\ ' ~tw '-aK= i_ » „"«.. ^ tr-i^ adolescent stages of the same species have 



-^!S. Iro ^^\ f^ yjj3^^^-/r ^^^ '^'^'^ ° made to represent distinct families by 



^^^i^\t/ i^A^ ^ y%C^'yQll^ authors who never studied the development of 



^^ r (&/*»Sb^ 1 /^fei\^ g| these beings. The species under consideration, 



when young, mostly contents itself with the 

 altered sweets of the roots which rot from the 

 punctures of Phylloxera, wh'le when older it 

 preys by preference on the lice themselves." 



'• Direct Remedies. The leaf-lice, which do not play such an important part in the 

 disease as was at first supposed, may be controlled with sufficient ease by a little care in de- 

 stroying the first galls which appear, and in pruning and destroying the terminal growth of 

 infested vines later in the season. The root-lice are not so easily reached. As the effort will 

 be according to the exigency, we may very naturally look to France for a direct remedy, if 

 ever one be discovered. But of all the innumerable plans, patented or non-patented, that 

 have been proposed, of all the many substances that have been experimented with under the 

 stimulus of a large national reward, no remedy has yet been discovered whicli gives entire 

 satisfaction, or is applicable to all conditions of soil. Nor is it likely that such a remedy 

 ever will be discovered. 



" While, therefore, not very satisfactory results have followed the use of pure insecti- 

 cides, the application of fertilizers intended to invigorate the vine, and at the same time in- 

 jure the lice, lias been more productive of good. Especially has this been the case with fer- 

 tilizers rich in potassic salts and nitrogenous compounds, such as urine. Sulphurct of potas- 

 sium dissolved in liquid-manure ; alkaline-sulphates, with copperas and rape seed ; potassic 

 salts, with guano ; soot and cinders are, among other applications, most favourably mentioned. 

 Mr. Riley closes his very able Essay with the following remarks: — "We have in the 

 history of the Grape Phylloxera, the sin<j;ular spectacle of an indigenous American insect 

 being studied, and its workings understood in a foreign land, before its presence in its most 

 injurious form was even suspected in its native home. The Franco Prussian war, with all 

 its fearful con.sequences to France, has passed away ; the five milliards of francs (one thous- 

 and million dollars) have been paid as indemnity to her victors, in so short a time that the 

 civilized world looked on in wonder and astonishment. Yet this little Phylloxera, sent over 

 doubtless in small numbers, by some American nurseryman, a few years since, continues its 

 devastating work, and costs that unfortunate country millions of francs annually. The last 

 German soldier has been removed -at terrible cost it is true — from French soil, but the 

 Phylloxera army remains ; and if another five milliard francs could extirpate the last indi- 

 vidual of this liliputian insect host from her soil, " la belle France" would be cheaply rid of 

 the enemy. Had the world, twenty years ago, possessed the knowledge we at present have of 

 this insect and of its dangerous power, a few francs might have originally stayed its invasion 

 ©f that great vine-growing and wine-making country. Needs there any more forcible illustra- 

 tion of the importance of economic entomology ! " 



In confirmation of this statement, we read in the monthly report of the Department of 

 Agriculture (Washington, xVugust and September, 1874), that "the Prefect of the Depart- 

 ment of the Rhone, in France, has published a decree directing the mayor of each Commune 

 within his jurisdiction, upon the indication of the presence of the Phylloxera, to proceed at 



