INDEX. 



281 



Walnut caterpillar, 1-12. 

 Wheat, insects affecting, 220. 



" bulb-worm, 229. 



" joint-worms, 230. 



" midge, 231. 

 White arsenic, I s . 

 \Vhit<.' grub, 20. 

 White hellebore, 19. 

 White-marked tussock-moth, 13 

 White pine aphis, 151. 

 Willow aphis, toothed , 150. 

 Willow-grove aphis, 1 is. 



Willow-twig aphis, 147. 

 Wireworms, 213. 

 Woodpecker, red-headed, 143. 



Woolly aphis, 35. 



Woolly maple bark-louse, 11M. 



Xyleborus pyri, 70. 



Yellow-necked apple-tree caterpillar 

 46, 143. 



Zebra caterpillar, 194. 



