What are Insectivorous Plants?
Insectivorous plants are the ones that derive most of their nutrition from the insects they trap and consume. These plants grow in humid areas where plenty of sunlight and moisture is found. The nutrients in the soil there are scarce. That is why they trap and digest insects to absorb nutrients. Venus flytrap, pitcher plant and cobra lily are some of the insectivorous plants found in North America.
Characteristics of Insectivorous Plants
The insectivorous plants are found in the places where there is a lack of nutrients especially nitrogen. That is why these plants entrap insects and digest them to absorb the necessary nitrogen through their leaf structures.
The insectivorous plants are colourful and shiny in appearance. They have a pleasant odour and flavoured nectars that attracts insects. The insects approaching them are trapped and digested by the plant.
The mouth of the insectivorous plants has hair-lined tined edges that snap shut as soon as the insect touches the hair, thereby, trapping the insect behind the tines. There are trigger hairs present on the top of the suction trap. As the insect touches the hair a flap opens and the insect is dropped in a water-sac. The flap then reseals and the insect is not allowed to escape. Some plant stalks are covered in sticky mucus-like substance where the plant sticks and cannot move.
Digestive Enzymes and Organisms
Some insectivorous plants secrete digestive enzymes that dissolve the insect for absorption. Others have bacteria or mites in their digestive tract that mimic the functions of the human digestive tract. They digest the prey for absorption by the plants.
Also read: Modes of Nutrition in Plants
Wet Site Inhabitants
The insectivorous plants are found mostly in wet, damp, humid, and acidic soil deficient in nutrients, such as swamps, bogs, wetlands, coastal plains, etc. They are found in the wet regions of North America, Australia, and tropical regions.
Types of Traps
The leaves of the plants are modified in the form of traps. The trapping mechanisms are designated as active or passive depending upon whether they move to capture the prey or not. The different types of traps are mentioned below:
Pitfall Traps: These are found in a pitcher plant. They comprise of a hollow leaf with a lid, filled with liquid to digest the prey.
Snap Traps: These type of traps are found in Venus flytrap. They shut their leaves rapidly as the prey touches the trigger hair.
Bladderwort Traps: These are commonly found in Utricularia. They use a partial vacuum to suck the small organisms.
Flypaper Traps: These traps are sticky and adhesive. The leaves are covered in stalked glands that secrete sticky mucilage.
Lobster-pot Traps: These are found in corkscrew plants. They possess downward pointing hair that pushes the prey deep inside the trap.
The insectivorous plants digest the prey chemically using enzymes and bacteria. The end products of the chemical breakdown are absorbed by the plants to help them survive under unfavourable conditions.
Examples of Insectivorous Plants
More than 200 species of Drosera are known till date. They appear to be covered in dew. This appearance is actually a sticky digestive enzyme which fakes and attracts the insects. These plants trap and digest the insects.
These plants have a wide mouth lined with hair. These hair are sensitive structures. As soon as an organism touches this hair, the mouth snap shuts trapping the insect inside. Once the organism is digested, the leaves of this plant open up again to trap another prey.
Nepenthes is also known as pitcher plant. This is found generally in Asia, Sri Lanka, and Australia. This plant consists of the pitcher which produces a liquid on its own. The insects are attracted by the odour of the plant. Once the insect is trapped and produces movement in the plant, the plant starts secreting the digestive liquid. The organism is digested and the nutrients are absorbed.
These are also known as butterworts. They produce bright, colourful flowers to attract prey. They have dewy sticky leaves to trap the insects. These plants are dormant during the winter season.
It is also known as the corkscrew plant commonly grown in the wet terrestrial to semi-aquatic environment. It contains the Lobster pot trap that has small hair lined at the entrance. It is made up of two types of leaves- the underground leaves that absorb water from the soil and anchor the plant firmly in the soil. These underground leaves form hollow tubes. With the aid of water flow, the insects enter these tubes but cannot come out.
Also read: Morphology, Types and Modification of Leaves
For more details on Insectivorous Plants or other related topics, visit BYJU’S website or download BYJU’S app.
- Endemic Disease
- PEM (Protein Energy Malnutrition)
- Creutzfeldt Jakob Disease
- TSH (Thyroid-stimulating hormone)
- ADH (Antidiuretic Hormone)
Frequently Asked Questions
What are insectivorous plants?
Insectivorous plants are the ones that derive most of their nutrition by trapping the insects and consuming the insects. For eg., Venus flytrap, Bladderwort, etc.
How are insectivorous plants different from other plants?
Insectivorous plants are heterotrophs whereas other plants are autotrophs. The insectivorous plants derive nutrition by trapping and digesting the insects whereas other plants can prepare their own food by the process called photosynthesis.
How are insects attracted to the insectivorous plants?
The cupped leaf of these plants attracts the flying and crawling insects. The light emitted by the plants appeals the insects.
Why do insectivorous plants feed on insects?
Insectivorous plants are found in areas where the soil is poor in nutrients. It is poor in nitrogen which is very important for the growth of the plants, such as rockout crops and acidic bogs. This nitrogen is obtained by digesting the insects.
How do Nepenthes catch insects?
Nepenthes captures prey with a pitfall trap that relies on a micro-structured slippery surface. The upper rim of the pitcher is wet that causes the insects to slip by aquaplaning on thin film of water.