PEA AND BEAN INSECTS 75 



less seriously infested than when they are sown broadcast or 

 in nar»;ow drills. When the peas are grown in rows, the lice 

 can be controlled by spraying with "Black Leaf 40" tobacco 

 extract, 10 ounces in 50 gallons of water to which 4 pounds of 

 whale-oil soap have been added. A traction sprayer is used, 

 fitted with nine nozzles and arranged to spray three rows at 

 a time. One nozzle is directed downward and the other two 

 nozzles throw the spray slightly upward into the row. The 

 pump should be able to give a pressure of 120 to 150 pounds 

 when all nine nozzles are in operation. With this outfit it is 

 possible to work effectively on twelve acres of peas a day. In 

 spraying for the pea aphis, it is important to begin early, soon 

 after the winged forms from the clover appear in the field. If 

 the work is started on time, it is usually possible to control 

 the pest with two or three applications at intervals of about a 

 week. In Maryland, Delaware and New Jersey, it was found that 

 much loss could be avoided by raising the main crop of peas for 

 the cannery early in the season before the aphis became abundant. 

 At the time of the first serious outbreak of the pea aphis in 

 this country, spraying machinery and insecticides were not as 

 effective as those now on the market and spraying experiments 

 at that time gave very unsatisfactory results. Methods were, 

 therefore, devised for destroying the lice by mechanical means. 

 The aphids were brushed from the plants to the ground during 

 the heat of the day with pine boughs and a cultivator was 

 immediately run between the rows. In this way many of the 

 lice were either killed by the heat or buried in the soil. This 

 method is now little practiced under commercial conditions 

 but might be followed to advantage in the home garden. 



References 



Del. Agr. Exp. Sta. 12th Rept., pp. 169-186. 1900. 



Va. Truck Exp. Sta. Bull. 13. 1914. 



U. S. Dopt. Agr. Bull. 276. 1915. 



Smith, lOth Rept. State Ent. Va., pp. 32-63. 1914-1015. 



