1 84 



Bulletin 252. 



They live in the ground feeding on the roots of grasses, weeds, etc. Dig out 

 grubs from benekth infested plants. Thorough early fall cultivation of land 

 intended for planting will destroy many of the pupae. 



POTATO. 



The yellow striped beetle emerges from hibernation in the 



Colorado spring and lays masses of orange eggs on the underside of the 



potato-beetle, leaves. The larvae are known as " slugs " and " soft-shells " 



(Fig. 145) and cause most of the injury to the vines. Spray 



with Paris green 2 lbs. in ico gals, of water or arsenate of soda combined with 



Bordeaux mixture. It may sometimes be necessary to use a greater strength of 



the poison, particularly on the older "slugs." 



These small black beetles riddle the leaves with small holes and 

 cause them to die. Bordeaux mixture as applied for potato 

 Flea-beetles, ijiight protects the plants by making them distasteful to the 

 beetles. See under potato blight. 



CUCUMBER, MELON AND SQUASH. 



These yellow, black-striped beetles appear in numbers and 



Striped CUCUm- attack the plants as soon as they are up. Plant .early squashes 



ber-beetle. as a trap-crop around the field. Protect the vines with screens 



until they begin to run, or keep them covered with Bordeaux 



mixture, thus making them distasteful to the beetles. 



Squash vines are frequently 



Squash-vine killed by a white caterpillar, 



borer. which burrows in the stem 



near the base of the plant. 



Plant a few early squashes between rows of 



the late varieties as a trap-crop. As soon as 



the early crop is harvested, remove and burn 



the vines. When the vines are long enough, 



cover them at the joints with earth in order to 



develop secondary root systems for the plant in 



case the main stem is injured. 



These dark green plant-lice 

 Aphis. feed on the undersides of the 



leaves causing them to curl 

 and wither. Spray with kerosene emulsion 

 diluted with 6 parts of water. It is necessary 

 thoroughly to cover the underside of the leaves ; 

 the sprayer, therefore, must be fitted with an 

 upturned nozzle. Burn the vines as soon as the 

 crop is harvested and keep down all weeds. 



The rusty-black adult emerges from hibernation in the spring 



Squash and lays its eggs on the underside of the leaves. The nymphs 



stink-bug. ^^'ck the sap from the leaves and stalks causing serious injury. 



Trap the adults under boards in the spring. Examine the 



leaves for the smooth shining brownish eggs and destroy them. The young 



nyriiphs may be killed with kerosene emulsion. 



:^ 



Fig. 159. Imported cabbage- 

 u'oniis. 



