Download Beneficial Insects

Insects
Insects are one of the most diverse and abundant organisms on earth. With over 1 million
described species (mammals have 5,400 described species) they represent more than half of
all living organisms. Insects are found in nearly all environments including the ocean and
Antarctica! Many insects are considered pests, but there are many beneficial species we
could not live without.
All insects have three body segments (head, thorax, and abdomen), three pairs of legs,
compound eyes, a pair of antennae, and an exoskeleton made of chitin. Some insects have
wings. They can walk, swim, and fly. Insects develop in two different ways. The first is
called incomplete metamorphosis. The insect starts as an egg. When it hatches the insect is
called a nymph and looks similar to the adult form. This is similar to how humans develop,
where a baby resembles an adult. The second is called complete metamorphosis. The bestknow example of this is the butterfly life-cycle. The insect starts as an egg and when it
hatches the insect is called a larva. Before the larva can become an adult, it must pupate.
During pupation all the body parts of the larva rearrange and morph to become the adult
form.
Entomologists are people who study insects. They study how insects behave, where they are
found, what they look like, and how they interact with the world around them. They also
educate the public and non-entomologists about insects and how they interact with humans.
Entomologists try to find solutions to insect related problems, such as insects that cause
disease or insects that destroy crops.
Insect Body Parts
Head - The head is the part of the insect that contains the brain, two compound eyes, the
mouthparts, and the pharynx (the start of the digestive system). The two antennae are
attached to the head.
Thorax - The thorax is the body section between the head and the abdomen. The legs and
wings attach to the thorax.
Abdomen - The abdomen is the segmented tail area of an insect that contains the heart,
Malpighian tubules, reproductive organs, and most of the digestive system.
Leg - All adult insects have six legs.
Compound Eye - Insect compound eyes are made up of many hexagonal lenses.
Antenna - An antenna is a sensory appendage that is attached to the head of adult insects.
Antennae are used for the sense of smell and balance. Insects have two antennae.
Exoskeleton – Made out of chitin and is used by the insect for protection from the
environment and to help maintain moisture. It is also the frame for their internal anatomy
much like our skeleton is our frame.
Label the diagram below with the appropriate term from above. Color in the exoskeleton.
Incomplete Metamorphosis
Egg – The first stage in the insect life cycle
Nymph - The second stage in the insect life cycle that resembles the adult and develops into
the adult insect directly, without passing through an intermediate pupa stage
Adult – The reproductive stage in the insect life cycle
Label the diagram below with the appropriate term from above.
http://dragonflywoman.files.wordpress.com/2009/07/incomplete-metamorphosis.jpg
Complete Metamorphosis
Egg – The first stage in the insect life cycle
Larva – The juvenile stage in the insect life cycle that does not resemble the adult
Pupa – The non-feeding stage between the larva and adult in the metamorphosis of
holometabolous insects, during which the larva typically undergoes complete transformation
within a protective cocoon or hardened case
Adult - The reproductive stage in the insect life cycle
Label the diagram below with the appropriate term from above.
http://dragonflywoman.files.wordpress.com/2009/07/complete-metamorphosis.jpg
Insect Diversity
Beneficial Insects – Any insect that performs valuable services like pollination or pest
control (i.e. an insect that eats another insect)
Pest Insects – Any insect that is categorized as unwanted or injurious by humans. Injuries
could be categorized as crop or agriculture damage or vector human diseases.
Above Ground Insects – Spend the majority of their life cycle above ground. They feed or
pollinate plants above ground.
Below Ground Insects – Spend the majority of their life cycle under ground. They tend to
feed on organic matter in the soil or the roots and shoots of plants.
Place the insect sticker in its appropriate habitat.