EPA Conditionally Approves Corn Plant Pesticide For European Corn
Borer

EPA has issued a conditional registration amendment approving the
full commercial use of a plant-pesticide to combat insect damage
in field corn. The corn plant-pesticide is Bacillus
thuringiensis (Bt) CryIA(B) delta-endotoxin and the genetic
material necessary for its production (p CIB4431). The pesticide
works by producing small quantities of a version of the naturally
occurring insect toxin, Bacillus thuringiensis CryIA(b)
delta-endotoxin, in the corn plant. The primary target of the
toxin is the European corn borer. EPA's registration is based on
a thorough examination to ensure that human health and the
environment would be protected. The registration is currently
limited to commercial field corn production; sweet corn and
popcorn currently remain registered for seed corn propagation
only. EPA's initial registration for this plant pesticide was in
late March, which allowed planting limited acreage for seed corn. 
Ciba Seeds of Greensboro, N.C., and Mycogen Plant Sciences of San
Diego, Calif., are the registrants and developers of the corn
plant-pesticide. The plant pesticide is produced when genetic
material necessary to make a truncated version of the naturally
occurring Bt CryIA(b) insect toxin is transferred to corn.
Transfer of this genetic material into plants enables them to
produce an insecticidal protein similar to that produced in the
bacterium.  The insecticidal protein similar to that produced in
the bacterium.  The insecticidal protein is produced in very
small quantities by the corn plant, and is non-toxic to mammals,
birds, and most other insects.  The use of this product is
expected to increase corn yields 10 to 15 percent and will help
to eliminate the use of more toxic pesticides used to control
insects on corn plants.  The agency has reviewed and approved the
resistance management plan for Bacillus thuringiensis corn plant
pesticide.  EPA concluded that the resistance plan submitted by
the registrants would reduce the possibility of resistance
developing for three to five years following use of the corn
plant-pesticide. The management plan includes, among numerous
actions, close monitoring of the plant-pesticide to determine if
resistance is developing in target insects. Commercial use of
Bacillus thuringiensis corn plant-pesticide is the second
commercial registration of plant-pesticides. In early May, EPA
registered Bacillus thuringiensis (CryIII(a) delta endotoxin and
the genetic material necessary for its production) in potatoes. 

(From: EPA Press Release, August 11, 1995)