1.1S) Insect Ecology (12-11-2016) Entomology

Name: - A.N. Bharghava Shyam

Admission Number: - MAE15007 (12-Nov-2018)

Topic Selected: - Entomology (Over view of insect ecology- Briefly)

Entomology:- 

Entomology is scientific study of Insects (Branch of Zoology). The father of Entomology is William Kirby with the support of William Spence.

History of Insects:-

Insects are very ancient than humans, Nearly 925000 species are there in world, among that now nearly 75 percent is already discovered so far. Silver fish is one of the most ancient insect evolved 400 million years ago.

Insects: -

Insects belong to Insecta Class & Arthropods phylum.  Class Insecta has 30 orders that are Hymenoptera (Some insects are Ant, Bees, etc.), Hemiptera (True Bugs, etc.), Diptera (Flies), Isoptera (Termites), orthoptera (Crickets) etc. classes.

Usually the life cycle of insects is called Metamorphosis. It has four stages that are Egg, Caterpillar, Pupa and Adult.

Characteristics (Body parts) of Insect:-

An Insect is an animal and body parts are divided into 3 regions that are Head, Thorax & Abdomen. Characteristics of insects are having compound eyes (which are made with units of Oomatidia, if more units of Oomatidia are there means more resolution power is there in eyes. Insects can see ultraviolent rays), 3 pairs of legs (All insects has 6 legs, if its legs are less than or more than 6 means it is not an insect.), one pair of antennae, usually with 2 pair of wings. Mouth part of insects is called maxillary pupa through this they will taste. The taste buds are called as pulps. They smell through antennal sensilla.  The skeleton is called exoskeleton; the exoskeleton is made of Chitin, which is very strong because of that decomposition takes place hardly in open air. Insects grow through molting (By leaving the old skin).

Food for Insects:-

The food for insects is leafs, pollen, grains etc.

Finding Food & Communicating to other fellow mates (Foraging): -

Insects find the food & communicate to other mates. It varies from insect to insect.  Insects find food through senses (Smell, taste, etc.), & brings it back through navigation & communication. Honey bees find food through waggle dance (The dance indicates direction, location & distance of nectar guide). Ants find food through Pheromone Trails (A random walk by scouts), etc.

Communication between Insects:-

Usually male produce sounds to attracts females and establish a territory.  Insects produce sounds in different ways, cricket produces the sound by rubbing the forewings, Grasshopper produces sound by rubbing their legs against wings, etc.

Insects Defenses:-

Insects have some different defense mechanisms to save themselves. The Defense mechanisms are Behavioral (Flying, Run, Hide, roll up, bites, etc.), Morphological (spines, hard body cover, limb shedding) & Chemical (Sting toxins, mimicry, etc.) are the different types of defence mechanisms.

Relationship with plants:-

Insects have 2 types of relationship (Interactions) with plants that are Mutualistic & antagonistic relations with plants. Mutualistic relation is help to both plants & insects, the Mutualistic interactions are pollination, seed dispersal, protectors & etc. While Antagonistic interaction heribivory & gall making.

Social Insects: - (Degree of sociality in insects)

The Insects are again segregated into 7 degrees that are Eusocial, Primitively eusocial, semi social, quasi-social, communal, sub social & solitary. These all degrees are based on how they live the life. (Sharing nest, cooperative brood care, division of labor, overlapping generations with in colony, etc. are the characteristics of this degree).  

Insects and Human: -  

Insects and humans are having mostly unintentional relationship.  Insects help humans & at the same time it also gives problems to humans.

Insects helps humans in pollination (Entomophily)) in generating new trees, plants etc.  & also eat pests in agricultural areas; Insects will help in becoming nutrious & protein food to us (Entomophagy).

Insects as a disease vector, through insects we get the diseases the Malaria, Dengue, sleeping sickness, etc.

References & Bibliography: -

Class PPT’s (1, 2, 8 &10)

Wikipedia

Group discussions on class text paper (For answers)