LECTURE 1.
Definition of entomology and importance of insects.
Introduction to Phyllum Arthropoda
Definition of ‘Entomology’ and importance of insects
The term entomology is derived from two Greek words. Entomon means an
insect and logos means to study. The term ‘insect’ is derived from the Latin word
insectum which means ‘cut into’.
Insects came into earth 480 million years ago. Man came to mother earth only
one million years ago. Out of 17 lakh living species on earth, 9.5 lakh species are
insects, 2.5 lakh species are plants and 0.45 lakh species alone are vertebrates.
Insects are harmful to man as pests of cultivated crops, animals, stored
products, carries of human diseases and pests of household and industrial articles.
They are also helpful as producers of honey, lac, silk, dyes, etc., pollinators of crops
and as natural enemies of crop pests. They also serve as important link in the food-
web of biological cycle in ecosystem.
Insects are grouped with other animals with similar characteristics in the
Phyllum Arthropoda.
Introduction To Phylum Arthropoda
There are about 1-2 million species of animals in the world and more than 70
per cent of these are insects. These animals are assigned to 29 phyla. Of these only
nine phyla are large, and their representatives are common and familiar to us. These
are called the major phyla. The other phyla are small and their representatives are
uncommon and of uncertain relationships.
Position of insects in animal kingdom and their relationship with other
Arthropods
Insects are invertebrates grouped in the phylum Arthropoda (Arthro-joint,
poda-foot) and subphylum Uniramia. Characters of the Phylum Arthropoda are
1. Segmented body
2. Segments grouped into 2 or 3 regions (tagma) known as Tagmosis.
3. Renewable chitinous exoskeleton
4. Grow by molting.
5. Bilateral symmetry of body.
6. Body cavity filled with blood and called as haemocoel.
7. Tubular alimentary canal with mouth and anus at anterior and posterior
ends.
8. Dorsal heart with valve like ostia.
9. Dorsal brain with ventral nerve cord.
10. Striated muscles (with dark and light bands).
11. No cilia (hair like vibratile structure on the surface of the cell).
https://drive.google.com/file/d/1d7zznOzMtqxz-OwDtJk2X09gFBiuI-40/view?usp=drivesdk
If you want more new information go this link
https://m.youtube.com/watch?v=seqytUxxSQ0
Definition of entomology and importance of insects.
Introduction to Phyllum Arthropoda
Definition of ‘Entomology’ and importance of insects
The term entomology is derived from two Greek words. Entomon means an
insect and logos means to study. The term ‘insect’ is derived from the Latin word
insectum which means ‘cut into’.
Insects came into earth 480 million years ago. Man came to mother earth only
one million years ago. Out of 17 lakh living species on earth, 9.5 lakh species are
insects, 2.5 lakh species are plants and 0.45 lakh species alone are vertebrates.
Insects are harmful to man as pests of cultivated crops, animals, stored
products, carries of human diseases and pests of household and industrial articles.
They are also helpful as producers of honey, lac, silk, dyes, etc., pollinators of crops
and as natural enemies of crop pests. They also serve as important link in the food-
web of biological cycle in ecosystem.
Insects are grouped with other animals with similar characteristics in the
Phyllum Arthropoda.
Introduction To Phylum Arthropoda
There are about 1-2 million species of animals in the world and more than 70
per cent of these are insects. These animals are assigned to 29 phyla. Of these only
nine phyla are large, and their representatives are common and familiar to us. These
are called the major phyla. The other phyla are small and their representatives are
uncommon and of uncertain relationships.
Position of insects in animal kingdom and their relationship with other
Arthropods
Insects are invertebrates grouped in the phylum Arthropoda (Arthro-joint,
poda-foot) and subphylum Uniramia. Characters of the Phylum Arthropoda are
1. Segmented body
2. Segments grouped into 2 or 3 regions (tagma) known as Tagmosis.
3. Renewable chitinous exoskeleton
4. Grow by molting.
5. Bilateral symmetry of body.
6. Body cavity filled with blood and called as haemocoel.
7. Tubular alimentary canal with mouth and anus at anterior and posterior
ends.
8. Dorsal heart with valve like ostia.
9. Dorsal brain with ventral nerve cord.
10. Striated muscles (with dark and light bands).
11. No cilia (hair like vibratile structure on the surface of the cell).
https://drive.google.com/file/d/1d7zznOzMtqxz-OwDtJk2X09gFBiuI-40/view?usp=drivesdk
If you want more new information go this link
https://m.youtube.com/watch?v=seqytUxxSQ0
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