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BIOCOMMUNICATION IN INSECTS
MENNI ROSHAN KUMAR
(2014026045)
CONTENTS
- Introduction- Types of insect communication - Visual communication. - Chemical communication. - Tactile communication. - Acoustic communication.
INTRODUCTIONCOMMUNICATION
* It is the exchange of information between individuals.
* Most insect language is innate. And most of their language is inherited, so each individual born with a distinctive vocabulary that shared only with other members of its own species.
Why do insects communicate ?
1- Recognition of kin or nest mates.
2- Locating or identifying a member of the opposite sex.
3- Facilitation of courtship and mating.
4- Giving directions for location of food.
5- Regulating spatial distribution of individuals, aggregation or dispersal; establishing and maintaining a territory.
6- Warning of danger; setting off an alarm.
7- Expressing threat or submission.
8- mimicry.
Insects may send a communication signals by:
1- Doing something (e.g. make a noise, release a chemical or flash a light).
2- By physical makeup (e.g. wing pattern, body colour) Like other animals, insects use their
five senses to acquire information about their environment (taste, touch, vision, hearing, olfaction (smell)). So insect communicate by:
Types of insect communication
Visual communication
Chemical communication
Tactile communication
Acousticcommunication
Contd.,
Visual communicationThe colour patterns and other markings of the wings (butterflies and moths) facilitate species recognition (like football players).
Some insects use bright colours, eyespots or other distinctive patterns to scare a way predators.
Contd.,* Some insects use dance-like body movements to
attract a mate or to communicate with the nest mate.
* Most visual communicate are effective during daylight, but some insects can generate their own light and use visual signals that can be seen at night.
Contd.,* Fire flies pulses of light are used in courtship
dialogue between a male (usually flying) and a female (usually perched in the vegetation). Each species has a unique flash pattern and response time.
Contd.,*Males of Photinus
pyralis emit a signal J shape flash during a rising flight movement and the female responds with a single flash after a tow second intervals. However ,the male Photinus comsumilis emit a series of 3.5 short flashes and a female respond after a double flash.
Contd.,*In alfalfa butterflies, males have U.V.
reflective scales and missing scales is a sign for male ageing.
Chemical communicationIt is the most common way of insect communication. These chemicals are divided into 2 groups.1- Pheromones: Chemical signals that carry
information from one individual to another member of the same species. These includes sex attractants, alarm substance and many other intra-specific messages.
2- Allelochemicals: Chemical signals that travel between individual of different species. These includes defensive signals such as repellents, compounds used to locate suitable host plant, and other signals to regulate inter-specific behaviours.
Functions of Pheromones:1- Queen bee emit pheromones that affects the development of workers bee.2- Ant use pheromones to recruit nest mates to a food source.
3- When laying their eggs, some flies moths and beetles use certain pheromones to repel insects of the same and competing species, thereby protecting their progeny.
4- Aphids give alarm pheromones that urge neighbouring aphids to flee from nearby predators.
Tactile communicationMany insects depend on physical contact because they have poor vision and sound receptors.
Social insects, such as ants, often stroke and groom each other with their antennae and mouth parts. However, both touch signals and chemical signals may be involved in these behaviours.
Bees dance
*Bees communicate by dance language.
*Bees use dance as a form of communication for distance and direction of food sources or nest sites.
Types of dances1- Round dance (running in a circle, is performed for close sites)
2- Transitional (or sickle) dance, For sites at an intermediate distance from the hive. This dance involves running in a semicircular (or moon) shape.
3) Waggle dance*The waggle dance is a language used by honey bee Apis mellifera. Which give the bees the ability to communicate the food sources locations.*The dance consists of different units or words of honey bee language
Acoustic communication
*Sounds are caused by vibrations that can pass through air, water, and solid structures*Because sound waves move rapidly through air, acoustic signals can be quickly started, stopped, or modified to send a time sensitive message.
*Although people can hear crickets, many insects make supersonic sounds that are above a person's range of hearing. These supersonic sounds have more than 20,000 vibrations each second.
Contd.,*some grasshopper and moths produce ultrasonic sounds as 80000 hertz. Entomologist can study these sounds by using Audi-transducer.
* Most insects detect sounds with a tympanic membrane in their abdomen (e.g. grasshoppers and moths) or in the tibia of the front legs (e.g. crickets)
*Grasshoppers rub their legs against their wings to advertise their presence. Many true bugs, beetles and ants make sounds by rubbing various other body parts together
Contd.,
Vibrational communication is widespread in insect social and ecological interactions. - Insects used water surface or plant surface to produce vibrational sounds. Plants are the most widely used substrate for transmitting vibrational signals. Plant species can vary in their signal transmission properties.
Reference :-- The principles of Insect
Physiology.- The insects structure and
function.- Internet.
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