PESTS AND DISEASES OF PLANTS 235 



weaker Bordeaux just as the buds are breaking open and repeat every 

 twelve days until about July 1st. Spray plants in winter with lime- 

 sulphur. 



Peas, Beans, Vetch, Clover, Alfalfa. 



Wireworms. Affect beans and many other garden plants. Rota- 

 tion of crops to starve out the infestations is perhaps the best treat- 

 ment. Where this cannot be done, use of the carbon bisulphide in 

 sandy ground is advised. Fertilize with nitrate of soda or kainit. 



Bean Aphis. Works on the leaves, young shoots and tender 

 pods, causing much damage. It is usually cared for by an internal 

 parasite and by a predacious ladybird, but if it becomes too de- 

 structive spray with kerosene or tobacco washes. 



Green Pea Aphis. Also attacks vetch, geraniums, malva and 

 many other plants. Spray with kerosene or tobacco washes. 



Cut Worms. Do great damage to all crops at certain seasons. 

 Plow around field so as to have straight side of furro-.v next to crop. 

 Use poison baits. 



Grasshoppers. Are very difficult to handle. Poisoned bnits have 

 given good results. Fall plowing of breeding grounds essential. 



Weevils. Fumigate seed with carbon bisulphide and be sure that 

 no infested seed is planted. Test by placing in water; infected seeds 

 will float. 



Bean Anthracnose. Produces brown sunken areas upon the 

 pods. It also attacks the young plants. Treat seeds with formalin 

 before planting. Spray with Bordeaux as soon as young seedlings are 

 well under way. Repeat if necessary. Practice clean cultural methods. 



Bean Blight. Attacks pods and produces wrinkled and distorted 

 seed. Treat seed with formalin before planting. 



Rust. Produces rust colored spots on foliage. Spray with 

 weaker Bordeaux. Burn all infested plants. 



Downy Mildew. Turns foliage dark and causes it to wilt and 

 die. Select clean seed. Spray with Bordeaux. 



Pea Mildew. Appears early and late, covering plant with a white 

 felt-like powder. Spray with weak Bordeaux or dust with sulphur. 



Onions, Leeks, Garlics, Etc. 



Onion Thrips. Attack the leaves and flowers, causing consider- 

 able damage in some localities. Spray with kerosene emulsion as an 

 insecticide and with Bordeaux as a repellent. 



Downy Mildew. Produces a white mould on the leaves, causing 

 them to wilt and die. Spray with Bordeaux. 



Onion Smut. First appears in the form of dark spots upon the 

 leaves and later as longitudinal rifts upon the bulbs. The following 



