INSECTS

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__By: Jean-Paul Saliba, Ayad Saoud, Michael Majdalani and Nisrine Doumit__

**Insects are the largest group in the animal kingdom. Scientists estimate there are over 1 million insect species on the planet, living in every conceivable environment from volcanoes to glaciers.**

__**HABITAT**__ ====All insects are different, none of them are alike. They all live in many unique places. They live in forests, grasslands, mountains, deserts, lakes, rivers, ponds and many other areas. Each insect has a specific structure to help it cope with the difficulties of living in those different areas. EXAMPLE: "the darkling beetles live in dry deserts, they get water from droplets that form on its body which later on fall into their mouths". The insects that live in grass are usually green or brown and pond insects can can fly from one pond to another. Another insect, like field crickets lay their eggs underground. The desert ant's habitat is an advantage to it, it stores food whereever it can so that it w on't starve later on.====

WHAT THEY FEED ON: Insects eat almost anything! Not all of them feed on the same thing, however they all belong to the same group, insects. There are many insects that feed on other insects, like mantises. Others like caterpillars prefer plants like green leaves, grass, and branches. A few insects such as fruit flies eat different kinds of fruits, while the insects that don’t fly and live in the soil feed on decaying plant life. Many more insect species don’t eat any of the food sources mentioned, they like dirt, manure, roots, stems, nuts, and sap. Another insect called the water bug feeds on fish, it is very large in size and is able to do so. A fact that you probably didn’t know is that larvae insects eat more than adults do.

HOW THEY OBTAIN FOOD: Just like their feeding habits, insects don’t obtain food the same way as others. Some have specialized structures while others just have their own way of getting food. A water bug for example captures fish by using its extremely long and powerful legs. Bees have a sticky body which helps them get the nectar in an easy way. Another insect called the weevil has the structure of a long hard snouts used to break the hard layer of acorns and other tough nuts. A dragon fly has a good and simple way to capture other insects. It has eyes that can see almost any angle, then when they find a pray, they use their powerful legs as a trap to capture it. Standing still for hours is something that praying mantises do. They stay still and wait for a pray to scome near them, then they attack rapidly.

** Complete Metamorphosis ** ** Most insects undergo complete metamorphosis. Each stage of the life cycle (egg, larva, pupa, and adult) looks different from the others. Entomologists call these in sects’ holometabolous. An example of complete metamorphosis is a monarch butterfly’s life cycle. **

** A monarch’s life begins as a single greenish egg under a leaf. When it hatches a larva that looks like caterpillar comes out. This larva eats its egg then begins eating milkweed leaves. In order for the larva to grow, it must molt. The old skin splits leaving the new skin underneath. Then the larva will continue to grow until it has molted 4 times. After it molts for the last time, the monarch becomes a pupa. During the pupal stage the monarch undergoes major changes. About a week later the monarch emerges from the sac it made (chrysalis) as a butterfly. **

** Incomplete Metamorphosis ** ** Incomplete metamorphosis only has three life cycle stages: egg, nymph, adult. The nymph looks like a smaller ver sion of the adult. The nymph is also wingless. An example of incomplete metamorphosis is an ant’s life cycle. **

=__//** Body Characteristics **//__= ** Insects have segmented bodies supported by an exoskeleton All insects share the three most common and basic body characteristics which are the head, the thorax, and the abdomen. Some insects have wings some with two pairs, and some with one pair. Most insects also have an exoskeleton, and antennae. Insects have segmented bodies supported by the exoskeleton. The head usually supports and consist of a pair of sensory antennae, a pair of compound eyes, and, if present, one to three simple eyes or ocelli and three sets of variously modified appendages that form the mouthparts. **

** Insects are the only invertebrates to have developed active flight capability, and this has played an important role in their success. These muscles are able to contract multiple times for each single nerve impulse, allowing the wings to beat faster than they would ordinarily. Having their muscles attached to their exoskeletons is more efficient and allows more muscle connections. **

So in conclusion we can say:

· In sects have three main body parts: head, thorax, and abdomen.  · Insects have a pair of antennae on top of their heads.  · Insects have a pair of compound eyes, and, if present, one to three simple eyes or ocelli.  · Some insects have two pairs of wings.  · Insects have which is an exoskeleton the hard, shell-like covering on the outside of its body.  · Insects muscles are able to contract multiple times for each single nerve impulse · Insects have three pairs of legs. They use the legs for walking, but sometimes an insect may have a pair of legs that are specially designed for jumping.




 * **System type : Insects System** ||
 * Muscular Skeletal :  An insect has an outer skeleton. The skeleton has three layers: the outer It has three pairs of legs and one or two pairs of wings. The legs are segmented and depending on the insect, may have a claw like structure on the last segment. Insect muscles are connected to their outside skeleton and are generally gray. ||
 * Digestion : **An insect has different kinds of mouths depending on the species. Some can chew, some can suck objects. The digestive system is a tube that goes from the mouth to the anus. It is divided into several sections, the foregut, the midguts and the hindgut.** ||
 * Nervous :  An insect has antennae that can be used to detect odors or to touch objects. Insects have two sets of eyes: simple eyes and compound eyes. The simple eyes have cornea, retina and pigment cells. There is a brain and nerve cells. ||
 * Circulation: An insect has a circulatory system that carries food, but not oxygen throughout its body. Since it does not carry oxygen, insect blood is green, not red like mammal blood. The insect heart is a simple tube running along their backs.  ||
 * Respiration : ** An insect breathes through thoracic and abdominal spiracles. Since the insect has no lungs, the spiracles go throughout the insect body to give gases. However the insect bodies are relatively small.** ||
 * Reproduction :  An insect generally reproduces sexually, although not always. The female genitals are external. The eggs are held in an ovipositor. The females' internal sexual organs are ovaries and the males' are testes that produce sperm. ||
 * Excretion: An insect passes food through its digestive system and the insect feces pass out of its anus from the hindgut. ||
 * Symmetry : An insect has bilateral symmetry. ||
 * Appearance: The insect is generally small. It can be many different colors depending on the species. ||

Fun Facts Grasshoppers can jump 40 times the length of their body. Ants can carry objects that weight 100 times the weight of their .own body. Insects live everywhere: forests, jungles, grasslands, deserts, swamps, ponds, and streams ,even inside the bodies of other animals! By current estimates there may be as many as 10 million different kinds. Some mosquitoes can beat their wings 600 times a second? A midge fly holds the record, with a wing beat of 1046 times a second. a leaf-cutter ant queen mates only once - just before establishing a new colony? She can then keep the sperm viable for up to 15 years and produce as many as 300 million offspring. The longest insect is a walking stick that can reach a length of 33 centimeters. Flies can "taste" with their feet.



__**<span style="font-family: 'Calibri','sans-serif'; font-size: 24pt; line-height: 115%;">Human Relationships **__

Many insects are considered pests by humans. Insects that are pest are usually parasitic mosquitoes, lice and bed bugs transmit diseases. Insects damage structures termites, or destroy agricultural crops locusts, weevils. Despite the large amount of effort focused at controlling insects, human attempts to kill pests with insecticides. If used carelessly the poison can kill all kinds of organisms in the area, including insect’s predators such as birds, mice, and others. Although many insects are beneficial to the environment and Insects. Many Toxic substances that have been used to kill insects remain in the environment.

=**//__ Importance of Insects __//**= <span class="goog_qs-tidbit goog_qs-tidbit-0" style="background-color: #ffff00;">Insects perform a vast number of important functions in our ecosystem. They aerate the soil, pollinate blossoms, and control insect and plant pests; they also decompose dead materials, thereby reintroducing nutrients into the soil. Burrowing bugs such as ants and beetles dig tunnels that provide channels for water, benefiting plants. Bees play a major role in pollinating fruit trees and flower blossoms. Gardeners love the bees and praying mantis because they control the size of certain insect populations, such as aphids and caterpillars, which feed on new plant growth. Finally, all insects fertilize the soil with the nutrients from their droppings.




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** Social insects ** **, ** any of numerous species of insects that live in colonies and have three characteristics: group integration, division of labor, and overlap of generations. Social insects are termites (Isoptera) and ants (Formicidae) and by various bees and wasps (Hymenoptera). Social insects are differentiated in structure, function, and behavior into castes, the major ones being the reproductives (//e.g.,// the queen) and the   steriles (workers and soldiers). Besides carrying out the basic function of reproduction, the members of the reproductive caste generally select the site for a new colony and excavate the first galleries. They are among the most diverse and ecologically important organisms on earth. As “super organisms,” they live in i governed societies. They can be studied at multiple different levels of biological organization, from gene to ecosystem, and much is known about their natural history. When you disturb an ant, it secretes a chemical signal called pheromone that rapidly diffuses through the air. Within a certain radius of the ant, the pheromone conveys the message "Flee!" to other ants. Outside the radius, the message changes to "Close in and attack!"