Are Insectivores Harmful to Humans?

Introduction

Insectivore is the term used for the organism that consumes insects. Insects are the prime source of food providing nutrients for insectivorous plants or animals. Another word for insectivores is entomophage, which is derived from the Greek word, where entomon means insect and phagein means to eat. The practice of consuming insects to obtain nutrition is known as entomophagy.

The insectivorous organisms comprise both plants and animals.

Insectivorous Animals

Amphibians were the first animals that ate bugs. When they evolved about 400 million years ago, they got sharp, cone-shaped teeth like crocodiles. The insectivore is the extension of the piscivore. Now, these mammals that eat insects are part of the order insectivora. Most insect-eaters have been reclassified, and the order Eulipotyphla shows that they are related to each other.

In places that aren't marine or polar, there are a lot of insects, and they make up a big part of the animal biomass. These animals obtain most of their food from insects and use them as a source of protein, particularly during breeding season.

Insectivorous Plants

Insectivorous plants get their nutrients from insects that they capture and eat. For some species, catching insects is a secondary way to get food, but for others, it is their primary way to get nourishment. They obtain the majority of their energy and minerals from insects, not from photosynthesis.

Their prey is not exclusively insects but also other arthropods. Plants have different ways to catch their prey. These include traps, sticky surfaces, hair-trigger snaps, bladder traps, tangled fur, and lobster pot trap mechanisms. Basically, they grow in places where the soil is thin or has little food, especially nitrogen, like acidic bogs and rock outcroppings.

Plants like the Venus flytrap, pitcher plants like butterworts, sundew, bladderworts, waterwheel plant, Brocchinia, and members of the Bromeliaceae family are examples of insect-eating plants.

They make partnerships with other living things that help them digest their food.

Many pitcher plants not only eat insects but also small animals with backbones like mice and lizards.

Trapping Mechanisms

There are basically five different kinds of trapping mechanisms in insectivorous plants. As per the mode of movements, traps can be active or passive.

Pitfall Traps

It is a prime example of convergent evolution since it has reportedly experienced evolution six times independently. One method of describing it is that it has a chamber inside.

Pitfall attracts insects into its trap by offering them nectar, which is made by the peristome and anthocyanin. Most pitcher plants have a loose waxy coat that gives insects a place to sleep and the water in the pitcher will make it a good place for other plants and animals to live.

This clever trap comes from the way the edges of the leaves are sealed. There are many of these plants in places where it rains. They adapted the same system to keep pitchers from overflowing when it rains a lot.

There were also toxic alkaloids found, which will help the plant catch its prey by killing the insects trapped within them through the toxic effect of chemicals. E.g., Cephalotus and Brochinia.

Flypaper Traps

In this kind of trap, plants use mucilage, which is a sticky substance like glue. The glands that make the substance are all over the leaves of the flypaper traps. This class has changed five times on its own to make this mechanism.

Thigmotropic growth involves rolling of the leaf blade (so the prey doesn't get washed away by rain) or making a pit on the surface below the prey to help plant digest. Some species don't have the enzyme nitrogen reductase, so they have to get nitrogen from insects. Triphyophyllum peltatum and Genus Pinguicula are a few examples of flypaper trap mechanisms.

Snap Traps

When hair on the leaf lobes of Dionaea muscipula are touched, the trap quickly shuts and this is known as a snap trap. The Venus flytrap and the Waterwheel plant are the only two living snap traps that share a common ancestor with a lineage that used flypaper traps in the past. Based on its shape and how it works, this trap is also called a "mouse trap," a "bear trap," and a "man trap."

Aldrovanda lives in water and eats small insects, while Dionaea lives on land and catches a wide range of arthropods, including spiders.

The hair in the trap lobes that act as triggers are sensitive. When this hair bends, stretch-gated ion channels in the membranes at the base make an action potential that travels up the midrib. In response, these cells pump out ions or make acid levels grow quickly.

The leaves on a Venus flytrap close when it rains or when something blows into it. When the insect fight for its life, they stimulate the internal lobes, which makes the lobes come close even more tightly. This forms a stomach where digestion takes place over a period of weeks. The leaves stay active for three or four times before they stop responding to touch.

Bladder Traps

The bladder trap can only be found in bladderworts, which belong to the genus Utricularia. Ions are expelled from the bladder by internal pumping. Because of these actions, the bladder develops a partial vacuum. A pair of trigger hair on the bladder's movable door is unique to aquatic creatures. Animals that come in contact with this hair are quickly pulled into the bladder and then digested. Although bladderworts lack a root system, certain terrestrial species have a stem that acts much like a root system.

Lobster Pot Traps

This kind of trap is easy for any insect to get in, but the bristles on the inside make it hard or impossible to get out. A Y shaped leaf lets the prey enter but not leave. Hair that points inwards make the prey move inwards. The water movement in a trough trap makes the prey move, just like the vacuum in a bladder trap.

Combination Traps

Sundews, like Drosera glanduligera, have a trapping mechanism that is a mix of flypaper and snap traps. In the same way, Nepenthes jamban has both pitfall traps and flypaper traps, with its sticky pitcher fluid.

Advantages of Insectivorous Plants & Animals

A few of the advantages of insectivorous plants and animals include −

• Insectivorous plants eat insects and digests them to receive the nutrients they need.

• An increase in the number of insects may cause an imbalance in the food chain. So, insectivorous plants and animals help in attaining that equilibrium state.

• In agriculture, insects can make it hard for the desired plants to grow. So, growing insectivorous plants and animals can help get rid of these pests.

• In the food chain, predators that eat insects allow energy to move up the chain.

Evolution

Charles Darwin spent 16 years growing plants that eat other plants. In his book, Darwin came to the conclusion that the characteristic of plants that eat animals was convergent.

Leon Croizat came to the conclusion that carnivory was monophyletic and put all plants that eat meat at the base of the angiosperms.

Researchers have found that the ability to eat meat developed separately in Poales, Caryophyllales, Oxalidales, Ericales, and twice in Lamiales.

Few fossils of insect-eating plants make it hard to figure out how they evolved. Most carnivorous plants are herbs, and traps are made by the plants' first growth. They are not solid like wood and bark.

Researchers are using genome sequencing to look at how carnivorous species have changed over time and how they are related to each other. Most plants that eat other plants live in places with a lot of light, water, and little nitrogen and phosphorus in the soil. This forces the plants to find other ways to get nitrogen.

Because of this, when there aren't enough nutrients, light, or water, catching and digesting prey has the biggest effect on photosynthesis gains, which helps plants change and adapt.

Conclusion

Insect-eating animals and plants use insects as their main or secondary source of food, minerals, and energy. Plants have many different kinds of traps, such as pitfall traps, snap traps, flypaper traps, bladder traps, and lobster pot traps.

Some carnivorous plants, like the sundew Drosera glanduligera and the fern Nepenthes jamban, have more than one type of trap. Researchers say that insect-eating plants have antifungal properties, so they can also be used in medicine.

So, now we can say that insect-eating animals and plants are safe for the ecosystem and for humans keeping the food chain’s balance.

FAQs

Q1. Which is the largest insectivorous plant?

Ans. Nepenthes rajah has enormous pitchers which can hold three quarts of liquid and can trap lizards and even small rodents.

Q2. Which is the smallest insectivorous plant?

Ans. Drosera brevifolia is a carnivorous plant of the family Droseraceae and is the smallest sundew species native to the United States.

Q3. Which plant is known as the king pitcher plant?

Ans. Nepenthes Rajah (King of pitcher plants) looks majestically beautiful and so deadly cute. It is a carnivorous (pitcher) plant and can only be found in the wild at Mount Kinabalu and neighboring Mount Tambuyukon in Sabah, Malaysian Borneo.

Q4. What are the natural liquids that kill flies?

Ans. A chemical known as Jasmonic acid which plants release when fed upon by herbivores to trigger defense compounds is the most natural liquid that kills flies.

Q5. Which chemical's smell will keep flies away?

Ans. The scent of eucalyptus can deter flies and other pests; however, the oils derived from the leaves are even more potent and can be drawn out by simply crushing and rubbing the leaves between your palms.