Introduction to Entomology and Importance of Insects

Arthropoda is the phylum of animals that include the insects, arachnids, crustaceans and others that are characterized by the presence of jointed limbs. Arthropodology(from Greek; arthron = joint, podos = foot & logous = to study) is a biological discipline concerned with the study of arthropods.

Entomology (from Greek; entomos, "cut in pieces or engraved/segmented", hence "insect"; and & logous = to study) is the Scientific study of Insects and a branch of arthropodology.

Entomologistsare the scientists who study, collect, rear and experiments on insects. The insects are easy to work upon for a number of reasons, easy to culture in lab, short life cycles, rapid population turnover and lesser ethical concerns to experiment on insects compared to other vertebrate insects.

Honeybee on a Sunflower

Biodiversity of Insects

Over 1 million species have been described and work has been published, but the estimated number is much higher as well as many species have been extinct. Entomologists estimate that estimated number of insects is between 3-80 million species. And among the described species 40% are beetles (order Coleoptera) which are more than 3,50,000 described species and next are bees (order Hymenoptera) which have more than 2,50,000 described species. More will be discussed in a separate article about biodiversity of insects.

Importance of Insects

Insects are key players in our ecosystem as a whole and they cannot be simply sidelined or eradicated from our planet. Their utmost significance is being summarized as follows;

1. Pollination and Seed Dispersal

Perhaps the most economically important function of insects comes in the form of pollination while collecting nectar from the flowers. If there are no honeybees for pollination of our agricultural crops, the estimated cost of artificial pollination is nearly 100 US dollars globally in 2003.

2. Nutrient recycling

Nutrient recycling is also a very eco-friendly activity of the insect world. The activities of insect such leaf-litter and wood degradation, dispersal of fungi, disposal of carrion and dung and soil turnover help to restore nutrients in the environment.

3. Honey production

Honey produced by the honeybees is perhaps one of the most important gift of nature because of many useful health benefits to humans.

4. Silk

Silk from the cocoons of silkworm moths, Bombyx mori, and related species has been used for fabric for centuries, and two endemic South African species may be increasing in local value.

5. Shellac

The lac insect Kerria lacca, is a source of a commercial varnish called shellac.

6. Chitin and its Derivatives

Chitin, a component of insect cuticle, and its derivatives act as anticoagulants, enhance wound and burn healing, reduce serum cholesterol and many other applications are being sought.

7. Source of food

Insects are either used as food or provide material to be used as food such as honey. Insects are also present at the lower levels of food webs, serving as food for other insectivorous animals like mammals, reptiles, amphibians and fish.

8. Model Organisms for Biological Research

Characteristics of certain insects make them useful organisms for conducting biological research. For example, high fecundity, short life span and ease of rearing and manipulation in lab, vinegar fly, Drosophila melanogaster has been model organism for research in cytology, genetics, molecular biology and developmental biology.

9. Transmission of Diseases to animals and plants

Insects are also important for our survival because they are responsible for transferring some most important diseases in human as well as to animals. Many insects are parasites of animals.

10. Predation and Parasitism

Predatory beetles and bugs are common in agriculture and often go unnoticed. But the valuable service provided by them cannot be denied. If the populations of these predators are disturbed as a result of chemical spray or some other practice then the populations of insect pests of crop are liable to increase.

11. Maintaining Plant Community Structure

Insects maintain the plant community structure through feeding on plants, plant parts and seeds; hence keeping a check and balance on natural habitats.

12. Critical Ecological Services

In the tropical areas, termites degrade woods to improve soil structure. Similarly, insect larvae in sea add to the organic matter of water bodies by the degradation of leaves and wood from the nearby terrestrial plants and add nutrients to water.

Hence there is more to entomology than we ever thought before. It is an interesting field of botany that cannot be ignored and must be well communicated to agriculturists because importance of insects cannot be denied in agriculture.