Carbaryl (Sevin), 1 pound per acre, may be applied to grain fields adjacent to 

 dairy pastures, but not after the heads have begun to appear. Use carbaryl on 

 grass pastures or hay fields if armyworms are very numerous (also in cornfields 

 if migration occurs), but warn area beekeepers that you are applying carbaryl. 

 Trichlorfon (Dylox), an organic phosphate insecticide, at 3/4 pound per acre, 

 may be used to within 21_ days of harvest, but the straw should not be used for 

 livestock feed. 



Corn Insects 



Black cutworms were found in a number of cornfields this week in the central sec- 

 tion, and the situation deserves careful attention. Some fields showed only 

 slight cutworm damage. In these fields, the worms were 1/2- to 3/4-inch long, 

 or about one-third grown. They will feed for another 2 weeks before pupating. 

 Continue to check fields; watch for leaf feeding, as well as cut, wilting, or miss- 

 ing plants. 



If the stand is being threatened, apply 3 pounds of toxaphene, 2 pounds of carbaryl 

 (Sevin) , 2 pounds of diazinon (granules preferred and cover by cultivating) , or 

 1 pound of trichlorfon (Dylox) per acre- -directed as a spray at the base of the 

 plants. We observed poor control this week where 2 pounds of toxaphene had been 

 used. 



For best results, use at least 20 gallons of water per acre, and cultivate or 

 rotary-hoe immediately to incorporate the spray deposit. Results will depend to 

 some extent on soil moisture and on rain immediately after spraying. If conditions 

 remain dry, the worms will be down several inches in the soil and control will be 

 poor. 



Seed corn beetles continue to cause damage in some fields where germination was 

 delayed due to lack of moisture. If replanting is necessary, apply diazinon or 

 phorate (Thimet) as a 7-inch band on the soil immediately ahead of the press wheel. 

 Most problem fields had received a broadcast or row treatment of aldrin or hepta- 

 chlor, indicating a resistance problem. The magnitude of resistance is still un- 

 known. 



Flea beetles continue to damage small corn, but should be declining. Damage is 

 most severe on corn under 10 inches high. If damage 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. 



Wireworms are causing damage after planting in some cornfields that were not 

 treated with aldrin or heptachlor. The round, wirelike, brown, hard-shelled worms 

 hollow-out seed or drill holes in the base of stalks, causing the death of the 

 plant. 



If the stand is lost, apply 2 pounds of aldrin or heptachlor per acre, disk- in im- 

 mediately and replant. A spray may give quicker kill than granules. Be careful 

 to avoid drift when spraying. 



In the central section, corn borer pupation is now complete; moth emergence ranges 

 from 16 to 32 percent. In northern sections, 76 to 84 percent of the borers have 

 pupated; first emergence occurred last week. 



