Energy Dynamics — Lab Prep

  1. Cabbage Pre-Weighing
    • To obtain the percent biomass of a representative cabbage before the experiment, use a paper towel to wash and pat dry the inner leaves of a grocery store cabbage.
    • Place the cabbage into a pre-weighed Petri dish on a balance to determine the wet mass of the vegetable, and then transfer the cabbage and the dish into a 37 °C incubator for 48 hours.
    • At the end of the incubation, weigh cabbage in the dish again to obtain the dry mass of the cabbage.
    • Then, calculate the percent biomass of the representative cabbage by dividing the final dry mass of the cabbage by the initial wet mass of the cabbage. After this, multiply the obtained value by 100.
  2. Hatching Pieris rapae Eggs
    • To hatch the Pieris rapae butterfly eggs, one week before the egg acquisition, sow radish seeds in pots containing fresh potting soil.
    • Place the pots in a sunny spot in the lab and water the soil daily, until it is just damp.
    • When the eggs arrive, place the egg strips egg-side down on different radish leaves. Note: Under indirect sunlight or indoor light, the eggs will hatch in around 48 - 72 hours.
    • When the caterpillars reach their fourth instar growth stage, transfer them onto a cabbage for three days, taking care to mist the caterpillars occasionally with water to prevent drying.