118 DESTRUCTIVE INSECTS OF VICTORIA : 



" These galls are round, fleshy, and corrugated. They 

 often number 100 or more upon a single leaf. A vine 

 which is much infected soon becomes sickly. The leaves 

 show distortion, turn yellow or brown, and during their 

 decay yield a faint and unpleasant odour. The stock 

 becomes stunted, and if the roots be uncovered they will 

 be found (especially as regards fibrils) swelled into small 

 blebs and tubercles. These are the result of the attacks 

 of the young phylloxera, which, after their development 

 on the leaf and escape from the gall, have descended into 

 the ground and commenced their subterranean existence. 



" These creatures are so numerous that the roots when 

 turned up often appear dusted with yellow grains. In 

 this condition they produce the greatest destruction to 

 the European vines. In America the aerial form appears 

 to produce the greatest evil. 



" Subterranean apterous female. — These apterous larvae 

 are smaller than the fuudatrix and are amber-yellow, with 

 an olive stain towards the head and vent. In later genera- 

 tions the forms are more flask-hke and colour ferruginous. 

 During their life underground they oviposit. One speci- 

 men, however, on dissection contained only eight eggs, 

 but this number is not constant. The egg-like bodies 

 are of a pale yellow colour and shining. When the larger 

 roots are attacked the cortex is loosened ; it rots and 

 scales ofl" under the irritation of the insects. When the 

 small fibres are affected, swellings and nodules mark the 

 injury done. 



" Professor Riley states that this root modification of 

 phylloxera passes through five or six generations, which 

 fact will account for the various forms and sizes seen 

 simultaneously crowding the roots of the plants. The 

 American forms appear to be more tuberculate than those 

 I have been able to examine through M. Lichtenstein's 

 courtesy. 



"About the month of July many of these underground 

 forms pass into nymphs and come to the surface, where 

 they develop wings, and then they fly to distant vineyards 

 to carry on the invasion. In America, during August, 



