-o- 



Potato leafhoppers continue their migration into the state from the south. These 

 tiny, green, wedge-shaped insects that skid sideways when disturbed cause yellowing 

 of second- and third- cutting alfalfa. No control measures are needed at this time. 



Corn Insects 



Corn seed beetles are damaging germinating cornfields in the central, western, and 

 northern sections. Most fields had been treated with a soil or seed treatment of 

 either aldrin or heptachlor, some with other chlorinated hydrocarbon seed treat- 

 ments- -indicating that seed corn beetles have probably developed resistance to 

 these chemicals. This problem was observed for the first time a year ago. 



From 5 to 30 percent of the stand has been destroyed in problem fields. Seed corn 

 beetles are about 1/4 -inch long, brown with a light -brown to tan border, or they 

 may also be a uniform chestnut brown. They move readily when disturbed. These 

 beetles hollow out the seed; the adults can usually be found in the damaged seed 

 or in surrounding soil. 



If replanting becomes necessary, apply diazinon at 1 pound of actual per acre as 

 a band on the soil surface just behind the planter shoe. 



Flea beetles are damaging occasional fields of corn. Newly emerging corn should 

 be watched for the presence of small, shiny, black beetles that jump readily when 

 disturbed and leave white scratch marks on the leaves. If damage is severe and 

 plants are being killed, apply 3/4 pound of carbaryl (Sevin) --preferred on dairy 

 farms- -or 1-1/2 pounds of toxaphene per acre as a band spray over the row. If 

 grassy areas in fence rows, road sides, or ditch banks border the field, also spray 

 these to prevent additional flea beetles from moving into the corn. Use carbaryl 

 for spraying these field borders, but do not use it in the vicinity of bee hives. 

 Do not contaminate fish-bearing waters when using toxaphene. 



Black cutworms are causing damage in only a few cornfields. Watch for cut plants, 

 especially in the low or poorly drained spots, for the next several weeks. Ap- 

 plications of 3 pounds of toxaphene, 2 to 3 pounds of carbaryl (Sevin) , 2 pounds 

 of diazinon (use as granules) , or 1 pound of trichlorfon (Dylox) per acre --directed 

 as a spray at the base of the plants- -will control small worms. Worms that are 

 1-1/2 to 2 inches long are more difficult to control. For best results, use at 

 least 20 gallons of water per acre; cultivate immediately to cover the spray deposit. 

 Rain following treatment will greatly improve control results. Let's get the cut- 

 worms early this year! 



Preplanting broadcast applications of 1-1/2 pounds of actual aldrin or heptachlor 

 (do not use on dairy farms) per acre is the best insurance against a cutworm problem. 

 Row treatments at planting time with these same insecticides provide erratic re- 

 sults against cutworms. 



Corn borer pupation is complete and emergence has reached 50 percent in the extreme 

 southern section. In the central section, approximately 40 percent of the borers 

 have pupated. In the northern section, pupation is just beginning. 



Small-Grain Insects 



True armyworms are present in thick, rank stands of small grain (wheat, barley, 

 rye) and grasses south of Highway 40. Along the north edge of this area, the 

 worms are about a week old (1/4 to 1/2 inch), while south of Highway 15 the worms 



