List of Text Figures 



Page 



Fig. 20 An exposed colony of plant-lice on a common roadside weed. 



(Original) 112 



Fig. 21 Leaves of white ash curled by a plant-louse. (Original) 112 



Fig. 22 Gall of sugar beet root-louse on leaves of narrow-leaf cot- 



tonwood. (Original) 113 



Fig. 23 A common wingless aphid; honey tubes at "A". (Original) . . 113 



Fig. 24 A branch of Euonymus species, showing star-shaped fruit. 



(Original) . 118 



Fig. 25 Sugar beet showing characteristic curling of leaves caused by 

 curly-top. (After Harry B. Shaw, Bulletin No. 181, U. 

 S. Bureau of Plant Industry) 124 



Fig. 26 Cross section of sugar beet, showing darkening of rings caused 

 by curly-top. (After C. O. Townsend, Bulletin No. 122, 

 U. S. Bureau of Plant Industry) 125 



Fig. 27 Entrance to burrow of tiger-beetle larva. There is never any 



loose soil at the entrance to these burrows. (Original) . . 131 



Fig. 28 Same burrow as shown in Figure 27, with head of larva resting 

 on level with the surface, ready to seize a victim. (Orig- 

 inal) 131 



Fig. 29 Nest of a mud-dauber, taken from rafter of an out-building. 



(Original) 135 



Fig. 30 A cabbage-worm killed by the larvae of a Braconid, the 

 cocoons of which are fastened to the window screen near 

 it. (Original) 136 



