4'02 



BUGS, INSECTS, ETC.— REMEDIES FOR. 



GRAPE PHYLLOXERA. — Not the 



least interesting feature in the economy 

 of our Phylloxera, are the different phases 

 or forms under which it presents itself. 

 Among these forms are two constant types, 

 which have led many to suppose that we 

 have to do with two species. The one 

 <type,which we have, for convenience, called 

 gallacola, lives in galls on the leaves; the 

 .other, which we have called radicicola, on 

 .swellings of the roots. 



Type Gallfflcola or Gall-inhabiting. — 



'The gall or excresence produced by this 



insect is simply a fleshy swelling of the 



: under side of the leaf, more or less 



wrinkled and hairy, Avith a corresponding 



, depression of the upper side, the margin 



of the cup being fuzzy, and drawn to- 



• gether so as to form a fimbriated mouth. 



It is usually cup-shaped, but sometimes 



greatly elongated or purse-shaped. 



Soon after the first vine leaves that put 

 ,^out in the spring have fully expanded, a 

 few scattering galls may be found, mostly 

 on the lower leaves, nearest the ground. 

 These vernal galls are usually large (of 

 - the size of an ordinary pea), and the 

 normal green is often blushed with rose 

 where exposed to the light of the sun. 

 On carefully opening one of them (Fig. 

 43) we shall find the mother-louse dili- 



- Fig. 43. — Under Side of Leaf Covered 

 with Galls. 



gently at work surrounding herself with 

 pale-yellow eggs of an elongate oval form, 

 scarcely .01 inch long, and not quite half 

 as thick (Fig. 44). She is about .04 inch 

 long, generally spherical in shape, of a dull 

 .orange color and looks not unlike an im- 



mature seed of the common purslane. At 

 times, by the elongation of the abdomen, 

 the shape assumes, more or less perfectly, 

 the pyriform. Her members are all dusky, 

 and so short, compared to her swollen 

 body, that she appears very clumsy, and 

 undoubtedly would be outside of her gall, 

 which she never has occasion to quit, and 

 which serves her alike as dwelling-house 

 and coffin. More carefully examined, 

 her skin is seen to be shagreened or mi- 

 nutely granulated, and furnished with 

 rows of minute hairs, which which more 

 particularly described elsewhere. The 

 eggs begin to hatch when six or eight 

 days old, into active, little, oval, hexapod 

 beings, which differ from their mother in 

 their brighter yellow color and more per- 

 fect legs and antennae, the tarsi being fur- 

 nished with long, pliant hairs, terminating 

 in a more or less distinct globule. These 

 hairs were called digituli by Dr. Shinier, 

 and they lose their globular tips and be- 

 come more or less worn with age. In 

 hatching, the egg splits longitudinally 

 from the anterior end, and the young 

 louse, whose pale yellow is in strong con- 

 trast with the more dusky color of the egg- 

 shell, escapes in the course of two minutes. 

 Issuing from the mouth of the gall, these 

 young lice scatter over the vine, most of 

 them finding their way to the tender ter- 

 minal leaves, where they settle in the 

 downy bed which the tomentose nature 

 of these leaves affords, and commence 

 pumping up and appropriating the sap. 

 The tongue-sheath is blunt and heavy, 

 but the tongue proper — consisting of 

 three brown, elastic, and wiry filaments, 

 which, united, make so fine a thread as 

 scarcely to be visible with the strongest 

 microscope — is sharp, and easily run un- 

 der the parenchyma of the leaf. Its punc- 

 ture causes a curious change in the tissues 

 of the leaf, the growth being so stimulated 

 that the under side bulges and thickens, 

 while the down on the upper side in- 

 creases in a circle around the louse, and 

 finally hides and covers it as it recedes 

 more and more within the deepening 

 cavity. Sometimes the lice are so crowd- 

 ed that two occupy the same gall. If, 

 from the premature death of the louse, or 

 other cause, the gall becomes abortive 

 before being completed, then the circle of 

 thickened down or fuzz enlarges with the 

 expansion of the leaf, and remains (Fig. 



