Entomophily

What Is Entomophily?

Entomophily refers to the process of pollination carried out through insects. In this system, huge numbers of bees, butterflies, and beetles visit flowers for nectar and pollen but, in the course of their behaviour, transfer pollen from one flower to another.

Characteristics of Entomophilous Flowers

The characteristics of entomophilous flowers are:

Bright Colouration & Showy Flowers

These flowers display vivid colours and attractive visual patterns to draw the attention of insects for pollination.

Fragrance Production

They produce sweet or strong scents that help insects locate the flowers even from a distance.

Nectar Availability

A rich supply of nectar acts as a reward, increasing the number of insects and helping in pollen transfer.

Sticky, Spiny Pollen Grains

Their pollen is sticky or spiny so it easily attaches to the bodies of visiting insects, ensuring effective pollination.

Specialized Floral Structures

These flowers often have structures like broad landing platforms or directional nectar guides that help insects access nectar while facilitating pollen pickup and deposition.

Mechanism of Pollination by Insects

Mechanism of pollination by insects is discussed below:

Attraction Phase

Plants dependent upon entomophily have large, showy flowers with bright colours, fragrant scents, and a good amount of nectar, all attracting the attention of insect pollinators.

Transfer of pollen

Moving from flower to flower in search of nectar, pollen grains stick on the body parts of insects from the anthers and deposit them on the stigma of other flowers.

Mutualism

Entomophily represents a mutualistic association between plants and insects. There is some benefit gained by the two interacting species from each other.

Types Of Insect Pollinators

Different types of insect pollinators are:

Bees

They are among the best and get attracted by flowers that are very coloured and have a smell. They collect nectar and pollen hence providing cross-pollination.

Butterflies

These insects get attracted by brightly coloured flowers and aid in pollination since pollen sticks to them as they drink nectar.

Beetles

Some flowers are specific to beetles. These insects could, in some cases, lead to pollination. However, they are relatively poor compared to bees in this function.

Moths

Nocturnal moths visit night-blooming flowers and participate in pollination during low light.

Significance Of Entomophily

The significance of entomophily are:

Enhances Genetic Diversity

Entomophily promotes genetic diversity in the population of plants through cross-pollination.

Essential for Food Production

Insect pollination process is necessary for the proper development of fruits, vegetables, nuts, and many other crops.

Supports Ecosystem Stability

Insect pollination facilitates the duplication of a wide variety of plant species and thus helps in the health and stability of ecosystems.

Threats To Entomophily

Threats to entomophily are:

Pollinator Decline

Habitat loss, pesticide use, and climate change have already reduced the populations of insect pollinators, thus posing a threat to plant reproduction and food security.

Monocultures

Agricultural practices that favour monocultures can reduce the availability of diverse flowering plants, impacting the populations of these pollinators.

Invasive Species

Non-native species may outcompete native plants and disrupt the relationship between plants and their insect pollinators.

Entomophily NEET MCQs (With Answers & Explanations)

Important questions asked in NEET from this topic are:

• Mechanism of Pollination by insects

• Significance of entomophily

Practice Questions for NEET

Q1. Attractants and rewards are required for :

1. Anemophily

2. Entomophily

3. Hydrophily

4. Cleistogamy

Correct answer: 2) Entonomophily

Explanation:

To sustain animal visits, the flowers have to provide rewards to the animals. Nectar and pollen grains are the usual floral rewards. For harvesting the rewards from the flower, the animal visitor comes in contact with the anthers and the stigma. The body of the animal gets a coating of pollen grains, which are generally sticky in animal-pollinated flowers. When the animal carrying pollen on its body comes in contact with the stigma, it brings about pollination. In some species, floral rewards are in providing safe places to lay eggs; an example is that of the tallest flower of Amorphophallus. One biotic agent for pollination is insects which transfer pollen grains to the stigma of flowers. this is known as entomophily and plants are characterised by attractive and brightly coloured flowers.

Hence, the correct answer is option 2) Entomophily.

Q2. In Ficus pollination is affected by

1. Blastophaga

2. Acheronita atropos

3. White Ermine

4. Mother Shipton

Correct answer: 1) Blastophaga

Explanation:

Ficus carica and other Ficus spp. of Moraceae

• Flowers of Ficus plants are enclosed within the hollow pear-shaped hypanthium inflorescence.

• There is a narrow ori­fice for entering the receptacle within which there are three types of flowers male, female and gall.

• Figs are pollinated by the gall wasp (Blastophaga) which crawls into the receptacle and lays eggs inside the ovules of the ‘gall flowers’ which it can easily reach by its ovipositor because of the shortness of the style.

• The eggs develop larvae which feed on the ovules and form galls.

• After passing the pupa stage, the larvae develop into mature wasps and crawl out of the fig.

• In so doing they brush against the male flowers near the orifice carrying away pollen on their bodies.

• These pollen-laden insects then enter fresh figs where they pollinate the long-styled female flowers and lay eggs within the ‘gall flowers’ in their turn.

Hence, the correct answer is option 1) Blastophaga.

Q3. In which of the following pollination takes place by lever mechanism?

1. Salvia

2. Ficus

3. Ocimum

4. Antirrhinum

Correct answer: 1) Salvia

Explanation:

Salvia has got a bilabiate corolla with two fertile epipetalous stamens. The stamens and pistil remain hidden under the upper lip. The flower is protandrous and the short epipetalous filament of each stamen is connected to the peculiar distractile con­nective which is long and lever-like, its two unequal arms separating the two anther lobes. The basal lobe of the anther is sterile while the upper lobe is fertile. A slight pressure on the lower anther lobe brings the upper lobe down.

Hence, the correct answer is option 1) Salvia.

Also Read:

• MCQs on Insect Pollination

• Double Fertilization

• Embryogeny in Monocots

Recommended Video on Entomophily