Grow Seed corn 



beetle beetle 



-2- 



Corn Insects 



Flea beetles continue to damage small corn. Damage 

 is most severe on corn under 10 inches high. If dam- 

 age is severe and plants are being killed, apply 3/4 

 pound of carbaryl (Sevin) or 1 1/2 pounds of toxa- 

 phene per acre as a band spray over the row. 



Seed corn beetles and a ground beetle were observed 

 damaging germinating corn. The seed corn beetles 

 (about 1/4 inch) are brown with a light tan border 

 on their wing covers or a uniform chestnut brown; 

 the larger ground beetle (nearly 1/2 inch) is metal- 

 lic green. Both move about rapidly and can be found 

 around the seed in cracks or on the surface. On the 

 average, from 1 to 10 percent of the stand had been 

 destroyed in fields, generally in spots. Most prob- 

 lem fields had received a row treatment with either aldrin or heptachlor and we 

 suspect that seed corn beetles are becoming resistant to these insecticides. 



Damage is greatest when germination is slow, as during cool periods. Warm temper- 

 atures and rapid germination and growth of the seedling plant will lessen problems. 

 \o chemical control is recommended at this time. 



Black cutworms are causing damage in occasional cornfields. Continue to check 

 fields and watch for missing, cut, or wilting plants. If the stand is being threat- 

 ened, apply 3 pounds of toxaphene, 2 pounds of carbaryl (Sevin) , 2 pounds of diazi- 

 non (granules preferred and cover by cultivating) , or 1 pound of trichlorfon (Dylox) 

 per acre- -directed as a spray at the base of the plants. For best results, use at 

 least 20 gallons of water per acre, and cultivate immediately to cover the spray 

 deposit. 



If replanting is necessary, apply and disk- in 5 pounds of aldrin or heptachlor 

 per acre (heavier than normal rates are needed for the larger worms) for corn. 

 Do not use aldrin or heptachlor if soybeans are to be planted, or on dairy farms. 

 On dairy farms, broadcast and disk- in 2 pounds of actual diazinon per acre to con- 

 trol cutworms . 



In the central section, corn borer pupation ranges from 60 to 90 percent, emergence 

 from 4 to 20 percent. In northern sections, 20 to 60 percent of the borers have 

 pupated and first emergence occurred this week. Some larvae have not yet pupated 

 in these sections so that egg laying will still be taking place 4 to 5 weeks from 

 now. In the area west of a line from Savana to Pontiac to Petersburg to Edwards - 

 ville, where high overwintering populations exist, an average of approximately 5 

 percent of the field corn acreage could still warrant treatment for first -gene rat ion 

 borers. Be prepared to examine early planted fields in late June and early July 

 for borer feeding. 



Forage Insects 



Alfalfa weevil damage is about over. .As the worms mature, they stop feeding and 

 pupate (resting stage) . Spraying of the new growth of the second crop may still 

 be justified in occasional alfalfa fields south of a line from Paris to .Alton. New 

 spring adults of the alfalfa weevil were observed for the first time laying eggs 



