Insect protection from Bt

Bt stands for the naturally occurring bacterium Bacillus thuringiensis. Bt lives in the soil and is found all over the world. Bt produces a protein  that is not digestible by caterpillars, basically giving the worm a case of fatal indigestion.  The Bt protein has been used in organic farming worm control for over 50 years.  It is applied directly to the plants (in this case, the silks).  In our case, insect protected varieties of corn are now able to produce this Bt protein themselves, expressing it in the silks and leaves that caterpillars consume.  It is beneficial for many reasons, chief among them the reduced use of chemical insecticides.  While the consumer encounters a very small amount anyway, especially since the silks and husks aren't consumed, we as growers do.  Insecticides have to be handled and applied and we do spend hours per day walking through treated plants and leaves  Bt drastically reduces our exposure to this since very little if any insecticide need be applied on Bt corn.  Another benefit to Bt is that it is only effective on caterpillars.  All other beneficial insects, including honeybees, are spared from a non-selective pesiticide that kills everything it comes into contact with.  Unfortunately, the downside to this is plenty of gnats, spiders and mosquitoes in the cornfield which wouldn't otherwise be there.  These are quite unpopular with our picking crew!   For further information about Bt, please check out the Bt Wikipedia page