When the corn has grown enough and the ECB egg masses show black heads, you are ready to proceed with the lab. PART I - Petri Dish Protocol Use a marking pen to write nonBt on the left half of the petri dish and Bt on the right half. Place a piece of filter paper in the petri dish. Add 2-3 drops of water to the filter paper. Make sure you keep track of each variety.
Researchers mark one leaf with a notch to help keep track.
Place the nonBt corn leaf on the left side of the plate and the Bt corn on the right side. Place the blackheaded egg masses on the leaf using a fine tip watercolor paintbrush. Place a drop of water on the leaf. Using the same brush, pick up an egg mass and place it on the leaf where you placed the water droplet. Cover the top of the petri dish with a damp paper towel and place the lid over the dish.