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Presentation on theme: "EMILIE ARBOUR MICHAELA PEACE ALLIE PENROSE JENNIFER YOUNG"— Presentation transcript:


2 INTRODUCTION Kingdom: Animalia Phylum: Arthropoda
Subphylum: Mandibulata Class: Hexapoda or Insecta 90% of arthropods are insects Approximately 1 million insect species

3 EVOLUTION Fossils from 350 mya had wings and were fully insects
Modern groups found 300 mya 280 mya modern groups are dominant 65 mya nearly all modern orders known Oldest fossils (350,000,000 years ago) had wings and were fully insects. In the upper Carboniferous (300,000,000 years ago), the modern insect groups were found, such as giant roaches. During the Permian period (280,000,000 years ago), modern groups along with paleodictyopteriods were dominant. Most modern orders were evolved by the time of the Cretaceous period (65,000,000 years ago).

4 EVOLUTION Legs as locomotive aids
Clustered into head, thorax and abdomen Disappeared or modified limbs Most believe that insects evolved from an organism that looked somewhat like the earthworm we see today. The theory is that these organisms grew legs from their segments in order to help with locomotion. Gradually the segments clustered together to form the head, thorax and abdomen. Limbs also disappeared or were modified, such as with the head, limbs evolved to become antennae and mouth parts.

5 EVOLUTION Wings grew from gill-like apparatuses
Compound eyes – one of the earliest identifiers It is believed that the gill flaps gradually began to grow longer. At first this didn’t really do much, other than add to the distance that the insects could jump. These flaps began to get larger and larger, until the insects were able to use them to controlling diving and gliding and eventually flight. Compound eyes are only found among insects, centipedes, crustaceans and horseshoe crabs. A compound eye is an eye that has a large number, a few hundred to thousands, of facets which all face slightly different directions. Each facet is attached by its’ own optic nerve to the eye. The facets do not produce a complete image, just a spot, like a tile in a mosaic. Resolution (the number of facets in the eye) determines how well the insect can see. Majority of insects can only see a few feet ahead of them. Their eyes cannot focus – the clarity of their vision depends on the resolution and how far away the insect is from whatever they are trying to see. The advantages to this time of eye is that the processing is so much different than ours – it offers a much greater flicker fusion rate. This means that it can process what it sees much faster, which allows it to fly at high speeds and not hit things. Compound eyes are also excellent for detecting motion.

Wingless insects 5 orders ~ 5425 species Example: Silverfish PTERYGOTA Winged and secondarily wingless insects 26 orders ~ 949,770 species Example: Grasshopper

7 CHARACTERISTICS Bilateral Symmetry Segmented Bodies Exoskeleton
Head, Thorax, and Abdomen Simple and Compound Eyes Exoskeleton Advantages and Disadvantages Jointed Appendages Legs and Antennae Cold Blooded 1. Bilateral Symmetry Insects have symmetrical body form, meaning that the right half of their body will be a mirror image of the left half 2. Segmented Bodies Insects bodies have 3 tagma (segments): head, thorax, and abdomen Insects are internally and externally segmented HEAD The antennae are located on the head segment. Insects can have 1 or 2 pairs of antennae, however, having only 1 pair present is more common. The antennae are the insect’s sense organs, used for feeling, tasting, hearing, and smelling Insects have TWO sets of eyes: Simple Eyes Can have 1 to 3 simple eyes present These eyes only sense light and darkness Compound Eyes Have 1 pair of compound eyes This set of eyes contains several thousand lenses, allowing for a larger field of vision, as well as hundreds of light-sensitive units, giving the insect true vision Effective at detecting movement and motion 3 sets of modified appendages that form the mouth A pair of mandibles for tearing and cutting food, a pair of maxillae and a single labium used to handle food THORAX Insects posses 3 pairs of segmented legs that are attached to the thorax If present, wings are attached to the thorax Insects may have 0, 1, or 2 pairs of wings Wings are NOT modified appendages, but rather flaps of the exoskeleton of the mesothoracic and metathoracic segments of the thorax The thorax is further segmented into the prothorax, the mesothorax, and the metathorax Each of the three thoracic segments contains one pair of legs The anterior wings (if present) are located on the mesothorax The posterior wings (if present) are located on the metathorax ABDOMEN Contains most of the internal digestive, respiratory, excretory, and reproductive structures The abdomen is the largest tagma of insects The abdomen can be further divided into 11 segments 3. Exoskeleton The bodies of insects are not supported by internal bones, but rather by a hardened exoskeleton made of chitin and protein This exoskeleton is hard and strong, providing structural support in place of bones, and is also impermeable to water The chitinous exoskeleton is like a specially made, form-fitting suit of armour for the insect The exoskeleton is produced by the insects “skin” and then hardens into a protective outer coating The exoskeleton, however, is rigid, and therefore has the potential to restrict the insect’s growth as it will not grow with them To overcome this, the insect must periodically molt, or undergo the process of ecdysis In ecdysis, the insect sheds its exoskeleton and makes a new, bigger one to allow for growth ADVANTAGES Protection Protects internal organs Defends against predators, parasites, and pathogens Isolates the insect from its surrounding environment Protects against/prevents water loss (desiccation) Provides something for the insects muscles to pull on Provides the material with which respiratory structures (trachea) and wings are developed DISADVATAGES Decreased flexibility To grow, the exoskeleton must be shed to allow for a new, larger one to be produced 4. Jointed Appendages ALL appendages of insects are jointed This includes both antennae and legs Insects also have jointed feet, allowing for efficient walking and swimming At the joints of the insect’s leg, the exoskeleton becomes soft and bendable to allow for sufficient movement Insect appendages/limbs are UNIRAMOUS, meaning they consist of a single series of segments attached end-to-end (NO BRANCHING) 5. Cold Blooded Insects are cold blooded, meaning that their body temperature is determined by the temperature of their surrounding environment This characteristic can also be called ectothermic, meaning that they rely on external sources for body heat

8 CHARACTERISTICS Circulatory System Respiratory System Digestive System
Nervous System 1. Circulatory System Insects have an OPEN circulatory system Have an internal cavity called a hemocoel in which the insect’s internal organs are bathed in body fluids (including blood). This direct contact allows for the exchange of nutrients, waste, and gasses 2. Respiratory System Insects do not have lungs Insects are air-breathing invertebrates Insects breathe through thoracic and abdominal spiracles (openings in the side of the exoskeleton on the thorax and abdomen) These spiracles go throughout the body of the insect to transport gasses Tracheae, a system of small tubes, run throughout the body of the insect to permit gas exchange 3. Digestive System Most insects are herbivores, however some are carnivores Insects have an alimentary canal, which is a tube that runs form the mouth to the anus The alimentary canal is divided into 3 sections: the foregut, the midgut, and the hindgut 4. Nervous System Insects have a brain and nerve cells (neurons) like humans, although much less complex Dorsal (back) brain is linked to a ventral (belly) nerve chord

9 REPRODUCTION Mainly sexual reproduction Hatch from eggs
Two types of development: complete and incomplete metamorphosis. -Male either insert their reproductive structure directly into the female's reproductive parts, or deposit a sperm package to be picked up by the female. Mainly sexual but some species are known to reproduce by parthenogenesis (the embryos develop without fertilization) -Eggs are laid in a protected place or produced internally.


Egg, Larva, Pupa, Adult. Larva and adult live in totally different habitats. 90% of insects go through Complete Metamorphosis. The larvae looks like a worm and hatches from the egg. As it grows, it also sheds it skin. It then grows into a pupa. While the pupa doesn't move around like the larva, it does eventually at this stage change from an immature form to adult form.


Three Stages: egg, nymph, adult Ex. Mayflies and dragon flies. When the nymph hatches from the egg, it looks like the adult insect except it is smaller, has no wings and cannot reproduce yet. As the nymph grows it outgrows its outside skeleton and it is shed. It then regrows a new one. This happens several times before it finally becomes an adult.

14 MOSQUITO Order: Diptera Life span: 2 weeks-6 months Habitat
Carry Deadly Diseases Anopheles Culex Aedes Blood suckers Habitat: they are most commonly found in ponds, marshes, swamps and wetlands. They like hot humid environments because this is the best for their growth and survival. They also need water for reproduction because they breed and lay eggs on water. There are more than 3,000 species of mosquitos -3 of these species are primarily responsible for human diseases -Anopheles—carry malaria -Culex- carry encephalitis, filanasis and West Nile -Aedes– carry yellow fever, dengue , encephalitis Only the females are the blood suckers. They use the blood not for their own nutrition but as a source of protein for there eggs.

15 FUN FACTS Ants can carry 50 times there weight
For every human about 1 million ants Usually only male cricket chirps 1% are harmful to humans THEY CAN BE GOOD! Products Honey Jewelry Agriculture Pollination Pest control Honey– healthy for humans (comes from bees) Jewelry– earing’s , necklaces (use beetles and other insects) Pollination– an insect will be taking pollen from one plant and it transfers it to another Pest Control– use insects to kill crop pests to protect the growing crops

16 WORKS CITED "Phylum: Arthropods, Class: Insecta - Animal Biology Spring 2010." Phylum: Arthropods, Class: Insecta - Animal Biology Spring N.p., n.d. Web. 30 Mar <> "Insects." INSECTS. N.p., n.d. Web. 30 Mar <>. "THE TiDE CHAsER: Insects (Phylum Arthropoda: Class Insecta) of Singapore." THE TiDE CHAsER: Insects (Phylum Arthropoda: Class Insecta) of Singapore. N.p., n.d. Web. 30 Mar <>. "Animal Diversity Web." Animal Diversity Web. N.p., n.d. Web. 28 Mar <>. "Phylum Arthropoda: The Arthropods." Phylum Arthropoda: The Arthropods. N.p., n.d. Web. 30 Mar <>.

17 WORKS CITED CONTINUED Insects. (n.d.). INSECTS. Retrieved from Characteristics of the Phylum Arthropoda. (n.d.). Retrieved from Thanukos, Anna. (n.d.). Inherited Characteristics. The Arthropod Story. Retrieved from University of Edinburgh. (n.d.). Class Insecta. Natural History Collections: Insecta. Retrieved from Cornell University. (n.d.). A Complete List of the 31 Living Insect Orders. Retrieved from Carter, J.. (n.d.). Phylum Arthropoda. Biology at Clermont College. Retrieved from University of Arizona. (n.d.). Arthropod Information. Using Live Insects. Retrieved from Klappenbach, Laura. (n.d.). Facts About Arthropods. Animals/Wildlife. Retrived from Phylum: Arthropods, Class: Insecta. Animal Biology Spring (n.d.). Retrieved from Evolution of the insecta. (n.d.). Retrieved from The evolution of flight. (1996, March). Retrieved from The evolution of the insect form. (1996, March). Retrieved from Bijlmaker, H. (2014). Good Insects. Insects. Retrieved from Facts about insects. (2009). Strange and interesting facts.Retrieved from Mosquito.(2014). National Geographic. Retrieved from Mosquito Habitats.(2014). Mosquito. Orkin. Retrieved from



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