Agriscience II

Intro to Entomology

What is Entomology?

Entomology is the study of insects. The study of insects includes their development, anatomy, physiology, life history, behavior, environment, and classification.

Interest Approach

What do lip balm (with beeswax), honey, a silk shirt, shoe polish, red soda, have in common?

Its true insects help provide the dye needed to make items red such a red soda

What contributions to the earth and mankind have been made by insects.

Objectives

Discuss the significance of entomology.

Describe the procedure for classifying insects.

What is the significance of entomology?

The significance of entomology A. Insect roles 1. Positive roles

a. Insects help nourish the soil by breaking down organic and inorganic materials in the environment, which is a natural form of “recycling.”

b. Insects pollinate fruits and vegetables. c. Some insects destroy other insects that harm

crops or animals, which reduces the need for pesticides.

What is the significance of entomology? d. Some insects provide food for other

animals. Without those insects, the food chain would be

disturbed. e. Researchers can use insects for product

development. (1) Lac comes from lac scale insects and is

produced mainly in India. 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?

(2) Beeswax can be used as a base for ointments, polishes, and candles. 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?

2. Negative roles a. Some insects (e.g., termites)

damage wood. b. Some insects (e.g.,

mosquitoes) transmit disease (e.g., malaria).

c. Some insects (e.g., Japanese beetles) can destroy crops.

What is the significance of entomology?

B. Human roles 1. Research

a. Insect research enables people to create pest-resistant varieties of some crops.

b. Insect research aids in the creation of insect-specific insecticides.

c. Insect research helps scientists with medical/drug research.

What is the significance of entomology?

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.

The chemicals are used in researching treatments and cures for cancer, multiple sclerosis, cystic fibrosis, and heart disease.

Also, fruit flies have long been used in genetic studies.

What is the significance of entomology?

2. Pest management helps prevent unnecessary destruction by harmful insects, thus minimizing crop losses.

How do you classify insects to order?

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. a. The head includes the

eyes, antennae, and mouth parts.

How do you classify insects to order?

(1) Eyes can be simple (small and located at the top of the adult’s head) or compound (large and located on the head of the adult—generally see only light and dark areas).

(2) Antennae are long, jointed feelers that come in a variety of types and grow from the insect’s head. Insects use antennae to detect odor, sound, and taste as well as to

feel the environment.

(3) 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 to order?

b. The thorax is the middle section of the body. It contains the nerve centers and muscles that control movement. 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. 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?

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. Some have none.

5. An insect usually has one or two pairs of wings. Some are wingless.

2 types of Metamorphosis

Simple

Complete

Metamorphosis of Insects

Simple Metamorphosis

Egg, then to larval stage where wings develope. There is no pupal stage

Metamorphosis of Insects

Complete Metamorphosis

Egg to

Larval stage (caterpillar) to

Pupa to

Adult butterfly

2 Types of Mouth Parts

Chewing

Sucking

Mouth Parts of Insects

Who Chews?

Stingers & Ants Cockroaches Dram-Flies Beetles & Weevils Fireflies Worms & Larvae Termites

Crickets Grasshoppers Praying Mantis Walking Sticks Earwig

Who Sucks?

Butterflies & Moths Bugs Flies Fleas Hogs Homoptera’s

How do you classify insects?

Order Metamorphosis Mouth Parts