O/T corn worms

Corn Borer Control: Shred and plow under cornstalks in or near fields where borers overwinter. This should be done in fall or early spring, before the adults emerge. Use pheromone traps to determine main flight period for moths, then release trichogramma wasps to destroy eggs. Beneficial insects, such as ladybugs and lacewing, will consume a large number of borer eggs. Spray Dipel Dust (Bt-kurstaki) or Monterey Garden Insect Spray (spinosad) to kill young caterpillars. Repeat applications every 4-5 days until tassels turn brown. Use botanical insecticides only as a last resort.

Note: Ladybugs will consume almost 60 borer eggs a day. Stink bugs, damsel bugs, spiders and hover fly larvae feed on young caterpillars.

If you are loosing alot of the tassels, it might be Corn borer. Your chances of killing these lie best with an commercial product. I suggest you contact a local agronomist or crop protection specialist and have them look at the field to determine you infestation level. You will need to go through a chem dealer any way as many of the products are restricted use. Also few people have a high clearance sprayer just sitting in the back yard ready to spray over the top of tall corn.