Download Intro-to-Entomology - Mid

Intro to Entomology
What is Entomology?
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Entomology is the study of insects.
The study of insects includes their development,
anatomy, physiology, life history, behavior,
environment, and classification.
An entomologist is a scientist - who spends most
of their time studying insects.
Objectives
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Discuss the significance of
entomology.
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Describe the procedure for
classifying insects.
Insect Facts
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Most Numerous animals on earth.
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More than 750,000 species of insects have been
identified.
Only about 10,000 are harmful to humans.
About 100,000+ species in North America
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Likley 1,000+ insect in a typical backyard
Less than 3% of those insects are damaging
Most insect are either beneficial or harmless
Harmful aspects of Insects
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Insects are considered pest when:
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transmit diseases to humans, domestic
animals, and plants
Are nuisance pest in and around the
home
Feed on crop and amenity (turf and
ornamental) plants
What is the significance of
entomology?
The significance of entomology
Insect roles
 1. Positive roles
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a. help nourish the soil by breaking down organic and
inorganic materials in the environment, which is a natural form
of “recycling.”
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b. pollinate fruits and vegetables.
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c. some destroy other insects that harm crops or animals,
which reduces the need for pesticides.
What is the significance of
entomology?
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d. provide food for other animals.
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Without those insects, the food chain would be
disturbed.
e. Researchers can use insects for product
development.
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(1) Lac comes from lac scale insects and is
produced mainly in India.
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Approximately 40 million pounds are used annually, as
it is an important ingredient of floor polishes, shoe
polishes, insulators, various sealants, printing inks, and
varnish.
What is the significance of
entomology?
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(2) Beeswax can be
used as a base for
ointments, polishes,
and candles.
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Forty percent of all
beeswax is used in
cosmetic manufacture
for lotions, creams, and lipsticks.
(3) Dyes are provided by scale insects and are
used in making cosmetics and in coloring cakes,
medicines, and beverages.
What is the significance of
entomology?
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2. Negative roles
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a. Some insects (e.g., termites)
damage wood.
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b. Some insects (e.g.,
mosquitoes) transmit
disease (e.g., malaria).
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c. Some insects (e.g., Japanese beetles)
can destroy crops.
What is the significance of
entomology?
B. Human roles
Research
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a. Insect research enables people to create
pest-resistant varieties of some crops.
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b. Insect research aids in the creation of
insect-specific insecticides.
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c. Insect research helps scientists with
medical/drug research.
What is the significance of
entomology?
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For example,:
Sigma Chemical Company purchases fireflies
(lightning bugs) for medical research.
These bugs contain luciferin and luciferase,
which are rare chemicals that scientists have
been unable to reproduce synthetically.
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The chemicals are used in researching treatments and
cures for cancer, multiple sclerosis, cystic fibrosis, and
heart disease.
What is the significance of
entomology?
Pest management:
helps prevent unnecessary destruction by
harmful insects, thus minimizing crop losses.
How do you classify insects to
order?
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Classifying insects to order
A. Insects come in different sizes and shapes,
but they share some distinguishing
characteristics.
1. An insect has a hardened
external skeleton composed
of three body regions: a
head, thorax, and abdomen.
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a. The head includes the
eyes, antennae, and mouth parts.
How do you classify insects to
order?
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b. The thorax is the middle section of the body. It
contains the nerve centers and muscles that control
movement.
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The legs and wings (if present) are attached to the thorax.
c. The abdomen is the section located at the rear of
the insect’s body and may be visible or hidden
beneath wings.
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It contains the internal organs and sexual organs.
The abdomen provides an area in which to store food that is being transported
to the nest, and it contains glands that secrete fluids to drive enemies
away or to create trails.
Some abdomens have needle-like projections for piercing or stinging.
How do you classify insects to
order?
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2. It has six jointed/segmented
legs on the thorax.
3. It has two antennae (one pair) to sense the
world around it from inside its exoskeleton
(outside skeleton).
4. An insect usually has one pair of
compound eyes.
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Some have none.
5. An insect usually has one or two pairs of
wings. Some are wingless.
Insect Orders
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Insects are divided up into 32
orders, or groups.
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The largest order is the beetles
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(Coleoptera) with 125 different families
and around 500,000 different species.
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In fact, one out of every four animals on earth
is a beetle.
2 types of Metamorphosis
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Simple
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Complete
Metamorphosis of Insects
Simple Metamorphosis
the wings develop externally during the larval stages. The larval stages, which are called
nymphs, look very similar to the adult insect. There is no pupal stage.
Egg, then to larval
stage where wings
develope. There is no
pupal stage
Metamorphosis of Insects
Complete Metamorphosis
wings develop internally during the larval stages. The larval stages look quite different from
the adult. Between the last larval stage and the adult stage there is a pupal stage which
usually is inactive.
The figure shows the development from an egg via the larval stage (caterpillar) and pupa to
an adult butterfly or moth.
Egg to
A larva is a young insect with a soft tubular
body and looks very much like a worm.
Larval stage
(caterpillar) to
Pupa to
The pupa stage is a dormant stage where the
larva changes into an adult.
Adult butterfly
2 Types of Mouth Parts
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Chewing
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Sucking
Mouth Parts of Insects
Mouth parts are chewing or piercing-sucking and determine how the insect feeds.
The strong, curbed, and toothed chewing mouth parts are used for chewing, cutting,
crushing, or grinding.
Piercing-sucking mouth parts are long and needle-like for piercing leaf surfaces or
skin.
How do you classify insects?
Order
 Metamorphosis
 Mouth Parts
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Insects Orders we will learn
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Lepidoptera – Butterflies, and Moths
Coleoptera – Beetles, Weevils, Rootworms
Diptera – Flies
Review
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What is the significance of entomology?
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How do you classify insects?