-2- 



4. Methyl parathion, 1/2 pound per acre . FOR USE ONLY BY EXPERIENCED APPLICATORS. 

 Effective for approximately 8 to 12 days. It is already too late to use this 

 material on fields that are to be harvested within 15 days. 



5. Azinphosmethyl (Guthion) , 1/2 pound per acre . FOR USE ONLY BY EXPERIENCED AP- 

 PLICATORS. Effective for approximately 10 to 14 days. Do not apply more than 

 once per cutting. It is already too late to use this material on fields that 

 are to be harvested within 16 days. Water temperature for the spray mix should 

 be above 55° F. 



Carbaryl (Sevin) recently received new label registration for use against alfalfa - 

 weevil larvae. Field trials in Illinois showed carbaryl to be less effective than 

 the insecticides now recommended . 



Pea aphid populations in forages are lower than last week. Aphid predators- -such 

 as larvae and adults of lady beetles, syrphid fly maggots, and aphis lions- -are 

 becoming numerous. Wasp parasites are also killing aphids. It appears that these 

 natural enemies will alleviate the problem in most fields. 



Potato leafhoppers , a pest of alfalfa, migrate several hundred miles into the state 

 each year from the south. The first migrant leafhoppers were found this week. 

 They are small, green, wedge-shaped insects that skid sideways when disturbed and 

 cause the yellowing on second and third cutting alfalfa. 



Spittlebugs have been hatching in northern sections. Occasional large-froth masses 

 with green to yellow nymphs inside are present in forages in the southern sections. 

 No economic damage is expected from spittlebugs. 



Small-Grain Insects 



Small, recently hatched armyworms have been found in thick stands of wheat in 

 southern and southwestern sections. They are not yet numerous enough to be a prob- 

 lem, but they may increase as more eggs are laid and hatch. It will be another 

 week or two before the infestation can be assessed correctly. Cool weather favors 

 this pest. 



Corn Insects 



Black cutworm moths have been present for several weeks , and we can expect tiny 

 cutworms to appear in cornfields anytime from now on. Watch for cut plants in the 

 low or poorly drained spots for the next several weeks. Applications of 3 pounds 

 of toxaphene, 2 pounds of carbaryl (Sevin), 2 pounds of diazinon (granules are 

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

 of the plants- -will control the small worms. Worms that are one to two inches long 

 are more difficult to control. For best results, use at least 20 gallons of water 

 per acre, and cultivate immediately to cover the spray deposit. Follow the pre- 

 cautions and restrictions on the label of the insecticide you use. Let's get the 

 cutworms 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 prob- 

 lem. Row treatments at planting time with these same insecticides provide erratic 

 results against cutworms. 



