Carnivorous plants are unusual because they obtain nutrients from eating bugs. Because of this survival trait, carnivorous plants have evolved unusual adaptations. Studying these adaptations and the differences between carnivorous plants and non-carnivorous plants is an option for an elementary school science fair project.
A Venus flytrap is a plant that contains two leaves at the top of a stalk. When an insect walks across these two leaves, they close with a snap, like a mouth. The plant then secretes digestive enzymes into the space between the two leaves that slowly dissolve the insect's internal protein, leaving only the exoskeleton behind.
A project to study flytraps is to touch the trigger hairs on the trap that close the leaves. Use a pencil to trigger the hairs and a stopwatch to determine the speed at which the hairs close. Determine if the plant’s leaves close faster or slower depending on the way in which the hairs are disturbed. Determine if the closure response times vary from plant to plant or leaf to leaf.
Carnivorous Plant Digestion Speeds
Pitcher plants attract insects into the pitcher-shaped leaves by releasing a scent. Once the bugs enter the plant’s pitcher, they are unable to escape. The pitcher plant slowly digests the bugs in the pitcher. The sundew traps plants with a sticky, fly paper-like substance that cover their leaves. Once insects become trapped on the leaves, the leaf margins roll over the bugs to aid in digestion.
You can compare flytraps, sundews and pitcher plants by allowing bugs, such as wingless fruit flies, to get trapped in each type of plant and then record the speed at which each type of plant digests the bug. Note which type of plant seems to be most proficient in trapping insects. Allow several types of insects into each plant terrarium and note which plants trap which insects. Determine which carnivorous plants are better at trapping particular insects.
Soil and Insect Trapping
Another project is to plant the same type of carnivorous plant in several different types of soil and soil pH levels. Then, allow the plants to trap insects and note which plants trap and digest their food fastest. This will help you to determine whether soil quality affects trapping and digestion speed.