sentence: Plants used in experiments were between 4 to 5 weeks old ( about 60 – 75 cm of size ) , the earliest stage found to be infested in the field.Larvae of stemborers ( B. fusca : Bf , C. partellus : Cp , S. calamistis : Sc ) and FAW were supplied by the Animal Rearing and Containment Unit ( ARCU ) at icipe .