of methoxychlor and 2 pounds of malathion per gallon) or a mixture containing 

 at least 1/2 pound of diazinon and 1 pound of methoxychlor per acre (2-1/2 to 

 3 quarts of the commercially prepared mixture Alfatox) . You may also use 

 1-1/4 pounds of malathion per acre (1 quart of the 5-pounds-per-gallon con- 

 centrate) in the morning, on days when air temperatures will be above 60° F. 

 Do not harvest for 7 days after treatment with methoxychlor, diazinon, or 

 mixtures of them. There is no waiting period for malathion. 



The quantity of finished spray applied per acre is also important. Use no less 

 than 4 gallons per acre by air or 20 gallons per acre by ground machine. The ex- 

 ception is on stubble, where 10 gallons per acre by ground will be sufficient. 



Corn flea beetles are numerous in many wheat fields in western and southern areas. 

 They are inflicting white scratch marks on the tips of leaves as they feed, but 

 this injury is not expected to reduce yields. Although corn flea beetles are 

 vectors of Stewart's disease in corn, they are not known to carry a wheat disease. 

 Treatment of wheat fields is not suggested. 



Newly emerging corn should be watched for the presence of these small, shiny, black 

 beetles that jump when approached. If damage to small corn is severe and plants 

 are being killed, apply 3/4 pound of carbaryl (Sevin) or 1-1/2 pounds of toxaphene 

 per acre as a band spray over the row. 



Spittlebugs are hatching in southern and central areas . The nymphs , orange to 

 yellow in color, cause damage by sucking sap from alfalfa and clover plants. They 

 are found behind leaf sheaths or on the leaves and stems, in masses of froth or 

 spittle. Chemical control is usually not profitable if spittlebug nymphs average 

 fewer than one per stem. 



Potato leafhoppers , a migrant from" southern states , appeared for the first time 

 this week in southern areas. They are small, green, wedge-shaped insects that 

 skid sideways when disturbed. They cause the yellowing on second- and third- 

 cutting alfalfa. No control measures are recommended at this time. 



Variegated cutworms are feeding in clover fields in southern Illinois. Presently, 

 they are very small and few in number. 



Plant Diseases 



There has not been a significant increase in the spread of Septoria leaf spot in 

 wheat during the last week. The dry weather has effectively prevented the spread of 

 the disease from the lower leaves to the upper ones. Spores are abundant on the 

 lower leaves in nearly all fields, and the disease could become serious if periods 

 of cool, wet weather occur. 



Powdery mildew is prevalent on the lower leaves and sheaths of both winter wheat 

 and winter barley in fields that are about knee high (jointing). Mildew tends to 

 be most severe in fields with high nitrogen fertility and high plant populations. 

 This disease can be expected to increase in severity as long as moderately cool 

 temperatures prevail. Rainy weather is not necessary for the development of this 

 disease. The disease can be recognized by the presence of white to gray mats of 

 fungus growth on the leaves and sheaths; the presence of spores gives the mats a 

 powdery appearance. Effective fungicides have not been cleared for use on wheat 

 and barley by the Food and Drug Administration. 



