By: Zia Mahmood Minhas
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The Insects |
The Insects
Insects are invertebrates belonging to phylum Arthropoda. They are also called Hexapoda due to three pairs of legs. The insects are the most diverse and successfully thriving animals on the earth.
There are one million described species, while the actual could be as high as 10 million.
They are found in all types of abodes, some being incredible habitats like frozen Arctic and Antarctica. They are found in soil, in the air, in the bodies of animal as parasites and on plants.
Brine Flies (Ephydra hyans) can survive and flourish in highly saline water of Mono Lake, California. Larvae of Psilopa petrolei is found in pools of crude oil and that of Scatella thermarum in hot springs of Iceland at high temperature of 48 degrees.
Beetles are the largest order of insects. One in every four animals is a beetle.
Social insects like termites, ants and honey bees constitute incredible 20% of total animal biomass on our planet. The weight of termites in the world outweighs total human weight by 10:1.
Body Structure and Life Cycle
A typical insect has following distinct characteristics:
- Exoskeleton or external skeleton.
- Body is divided into three main parts:
o Head bearing mouth parts, compound eyes and a pair of antennae.
o Thorax having three pairs of long and jointed legs and one or two pairs of wings in adults.
o Abdomen which contains organs for vital body functions like digestion, excretion and reproduction.
Insects have typically four stages of life in which they change forms, habitats and habits. These body forms are totally different from each other and the process of changing of forms is termed as metamorphosis. These stages are
- Egg
- Larva
- Pupa
- Adult
There are, however, adaptations and variations in the species.
Fascinating Facts About Insects
-Average age of insects is from hours to weeks. Had their age been one year there would have been a layer of 2-3 inch comprising of insects on whole of earth’s surface.
-The longest insects in the world are the stick insects. Their appearance is like a wooden stick which is a camouflage for predation. The specimens of Chan’s megastick( Phoebaeticus chani ) and another species Phryganistria chinensis have been reported to reach 36cm length. The length with front leg fully extended has been recorded at 56.7 cm
-Some butterflies and moths (lepidoptera) have wing spans up to 32 cm and an area of over 300 square cm. Butterfly has taste receptors on its feet. It has hair on the wings to detect changes in the air pressure. The butterfly colis as can distinguish two points separated by 30 microns as against human capability of 100 microns.
-Fairy flies parasite (Megaphragma caribea) is thought to be the smallest insect measuring just 0.17mm
-The locusts are very destructive insects. Its body is around 2.5 grams but can eat food equal to its body weight in a day. A large swarm of African desert locust (Schistocerca gregaria) may contain as many as 28,000,000,000 individuals weighing 70,000 tons of biomass and can devour up to 20,000 tons of plants in a day.
-Cricket is an incredible insect. You can calculate the temperature by the sound of cricket chirping. Count the no of chirpings in 15 seconds and add 39.This will give you temperature in farenheight. Cricket can hear using their legs. Sound waves vibrate a thin membrane on the cricket’s front legs. The female of cricket eats the male after mating.
The Social Insects
There are some insects which live in highly organized groups. There is division of labor for different specialized jobs. This behavior is termed as ‘Eusociability’. This phenomenon is defined by following characteristics:
- Cooperative care of young ones.
- Overlapping generations.
- Division of labor into reproductive and non reproductive groups.
-Ants, honeybees, wasps and termites are social insects. In such groups the reproductive functions are exclusive to queens and male members. The groups involved in reproductive function do not engage in other activities. The other functions are performed by workers who are mostly females. They perform specialized functions such as foraging for food, feeding larvae, building nests and defense against predators.
-The termites are highly organized social insects. They build very tall mounds for their colony. The life span of queen is about 25 years in which it lays 100-1000 eggs daily. 
Workers make up nearly 90-95 % of the population. They are wingless, sterile and blind. The soldiers are for defense against attack and fight physically with intruder and can secrete toxic substance. They have specialized mouth parts which at times so large that they cannot take their food and are fed by workers.
-The colonies of these insets present highly organized and disciplined behavior. We cannot but accept that such behavior cannot be achieved by the insects by their own effort and learning or coaching. It is therefore inculcated into their instinct by Allah the Almighty.
How Do Insects Communicate?
-Many insects possess very sensitive and specialized organs of perception.
-Some of the insects such as bees can perceive ultraviolet wave lengths.
-Antennae of male moths can detect the pheromones of female moths over the distance of many kilometers.
-Some insects like honey bees or yellow paper wasps (Politer versicolor) communicate through body movement or waggle dance.
-The insects who produce sound can also hear them; the frequencies may vary from species to species.
-Some insects like nocturnal moths can perceive ultrasonic emissions of bats which help to avoid the predators.
Significance of Insects
Insects are dominant species on this planet and constitute the major biomass share. They are significant to human beings in the following ways:
-Insects are major source of pollination for plants. While visiting flowers for nectar collection, they carry pollen sticking on their bodies to other flowers thus induce cross pollination. This results in production of healthy fruit and seed of various crops.
-Insects produce useful substances like honey, silk, wax and lacquer.
-Insects are also used in medicine .Fly larvae were formerly used to treat wounds.
-Some insects act as beneficial agents by predation or infecting diseases to harmful pests as parasites.
-Insects have high protein fat and mineral contents in their body. In some societies insects are cooked and relished as food.
-Insects are harmful as major farm pests affecting plants and livestock. Others act as carriers of deadly pathogens and inflict damages as parasites to humans and other animals.
Insects Mentioned in the Qur’an.
There are several references to insects in the Qur’an such as:
(وَأَوْحَىٰ رَبُّكَ إِلَى النَّحْلِ أَنِ اتَّخِذِي مِنَ الْجِبَالِ بُيُوتًا وَمِنَ الشَّجَرِ وَمِمَّا يَعْرِشُونَ ﴿٦٨
ثُمَّ كُلِي مِن كُلِّ الثَّمَرَاتِ فَاسْلُكِي سُبُلَ رَبِّكِ ذُلُلًا ۚ يَخْرُجُ مِن بُطُونِهَا شَرَابٌ مُّخْتَلِفٌ
(أَلْوَانُهُ فِيهِ شِفَاءٌ لِّلنَّاسِ ۗ إِنَّ فِي ذَٰلِكَ لَآيَةً لِّقَوْمٍ يَتَفَكَّرُونَ ﴿٦٩
Honey bee-Your Lord inspired the bees: ‘Take the mountains for your habitation, as also the trees and what they erect on a trellis. Then eat of all fruits and follow the path of your Lord, made easy for you’. From their bellies comes a drink of diverse colors in which there is healing for mankind. In this there is a sign for people who reflect.
(Soorah An-Nahl 16:68-69)
إِنَّ اللَّـهَ لَا يَسْتَحْيِي أَن يَضْرِبَ مَثَلًا مَّا بَعُوضَةً فَمَا فَوْقَهَا ۚ فَأَمَّا الَّذِينَ آمَنُوا فَيَعْلَمُونَ أَنَّهُ الْحَقُّ مِن رَّبِّهِمْ ۖوَأَمَّا الَّذِينَ كَفَرُوا فَيَقُولُونَ مَاذَا أَرَادَ اللَّـهُ بِهَـٰذَا مَثَلًا ۘ يُضِلُّ بِهِ كَثِيرًا وَيَهْدِي بِهِ كَثِيرًا ۚ وَمَا يُضِلُّ بِهِ إِلَّا الْفَاسِقِينَ ﴿٢٦
Mosquito–Allah shies not from drawing a parable even from mosquito or else anything large or small. Those who believe know it is truth from their Lord. Those who disbelieve say:”What did God intend by this parable?” Allah thereby leads many astray, And guides many. But the dissolute alone He leads astray.
(Soorah al-Baqarah 2:26)
يَا أَيُّهَا النَّاسُ ضُرِبَ مَثَلٌ فَاسْتَمِعُوا لَهُ ۚ إِنَّ الَّذِينَ تَدْعُونَ مِن دُونِ اللَّـهِ لَن يَخْلُقُوا ذُبَابًا وَلَوِ اجْتَمَعُوا لَهُ ۖ وَإِن يَسْلُبْهُمُ الذُّبَابُ شَيْئًا لَّا يَسْتَنقِذُوهُ مِنْهُ ۚ ضَعُفَ الطَّالِبُ وَالْمَطْلُوبُ ٧٣
The Fly–O mankind, a parable is struck, so listen to it. Those whom you worship instead of Allah cannot create a fly, even if they join forces to do so. And if flies were to rob them of something, they could not retrieve it from them: weak is the seeker and week is the thing sought! (Soorah Al-Hajj 22: 73)
These insects will be discussed in a bit detail in the next two articles.
