2Ent 102 Intro Ent

7/31/2019 2Ent 102 Intro Ent

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Arthropods and Human Health -

An Introduction

Entomology in Human Health

How Arthropods Effect Human

Health and Well-Being


An Introduction

Entomology is the study of

insects and related organisms

- all of which fall into the

Phylum Arthropoda

So, what is an Arthropod?


An Introduction

The Classification of Life

• Plantae

– Phyla

• Algae

• Slime molds

• True fungi

• Bryophytes

• Bacteria

• Animalia – Phylum Protozoa

• One-celled animals

– Phylum Porifera• Sponges

– Phylum Annelida• Segmented worms

– Phylum Arthropoda• Insects, spiders,

crabs, centipedes,etc.


An Introduction

The Biological Classification

System

• Based on shared characteristics

• Higher levels share more characteristics,

finer levels share fewer

• Kingdom

– Phylum

• Class

– Order

» Family

Genus

Species

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An Introduction

The Phylum Arthropoda

The “arthropods”

• Body consists of segments grouped

into fairly distinct regions


An Introduction





• Body segments (at least some) have

segmented appendages attached tothem.


An Introduction





• Body segments (at least some) have

segmented appendages attached tothem.

• Have an exoskeleton


An Introduction

Arthropod Characters

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An Introduction



An Introduction



An Introduction

The arthropod body covering is

referred to as an Exoskeleton in

both adults and immatures


An Introduction

Advantages and

disadvantages of an

exoskeleton• Protective armor -

prevents wear and tear

• Protection from invasion

by pathogens and harmful

agents

• Impermeable to water

• Base for muscle

attachment

• Does not expand - must be

shed in order to grow -molting

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An Introduction

Cuticular Appendages - Seta(e)

• Setae are hair-like

projections of the

cuticle which arise

from a trichogen

cell.


An Introduction

Cuticular Appendages -

Glandular Setae

• Glandular setaeproduce secretionsinvolved inprotection or communication


An Introduction

Some Commonly Encountered

Arthropods?


An Introduction

Now, Let’s Look at Insects!

The Insects are a Separate

Class of Arthropods

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An Introduction

Insects

(Adult Insects)

• Body with three distinct regions

– Head, Thorax, and Abdomen


An Introduction

Adult Insects



• Head with one pair of antennae and

paired mouthparts


An Introduction

Adult Insects



• Head with one pair of antennae andpaired mouthparts

• Thorax with three pair of legs - oneper segment


An Introduction

Adult Insects

• Body with three distinct regions – Head, Thorax, and Abdomen

• Head with one pair of antennae andpaired mouthpart

• Thorax with three pair of legs - oneper segment

• No locomoter appendages onabdomen (in adults)

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An Introduction

Adult Insects



• Head with one pair of antennae and pairedmouthpart

• Thorax with three pair of legs - one per segment

• No locomoter appendages on abdomen (inadults)

• With 0, 1 or 2 pair of wings.


An Introduction

Insect Characters


An Introduction

The insect body is composed

of three distinct regions

• Head

• Thorax

• Abdomen

• Thoraxwith threepair of

legsArthropods and Human Health -

An Introduction

Head with one pair of antennae

and paired mouthparts

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An Introduction

Insect Mouthparts

• Mouthparts vary depending on food

eaten and other functional needs

– Chewing

– Piercing and sucking

– Sponging

– Siphoning

– Chewing and lapping


An Introduction

Chewing Mouthparts


An Introduction

Chewing Mouthparts


An Introduction

Piercing and Sucking

Mouthparts

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An Introduction

Piercing and Sucking - Bugs


An Introduction

Piercing and Sucking -

Mosquito


An Introduction

Piercing and Sucking -

Mosquito


An Introduction

Piercing and Sucking

Mouthparts Mosquito

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An Introduction

Sponging Mouthparts

Some Flies


An Introduction

Sponging Mouthparts

Housefly


An Introduction

Sponging Mouthparts


An Introduction

Siphoning Mouthparts

Moth and Butterfly Adults

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An Introduction

Siphoning Mouthparts


An Introduction

Chewing and Lapping

Mouthparts

Bees


An Introduction

Wings - Insects are the only

Arthropods with Wings!


An Introduction

The Insect Abdomen

No walking appendages

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An Introduction

Ovipositor

Egg-laying device


An Introduction

“Stinger”

A modified ovipositor


An Introduction

Now, Remember the concept

of an Exoskeleton!


An Introduction

Metamorphosis and

Molting

Change

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An Introduction

Metamorphosis and Molting

Terminology

Stage - successive steps in the life cycle

1. egg stage2. immature stage

numbered instars between molts3. pupal stage (complete metamorphosis only)

4. adult stage


An Introduction

Molting


An Introduction

There are three types of

Metamorphosis found in insects

Ametabolous (“no” metamorphosis)

growth “without change”

immature is a young

Paurometabolous (simple, incomplete, gradual)

immatures look like adults

immature called a nymph (naiad)

Holometabolous (complete, complex)

pupal stage, significant transformations

immature called a larva(e)


An Introduction

Insects with “No”

Metamorphosis

• Egg, Immature (young) instars, adult

• Found in “primitive” insects

• Insects do molt but each young

instar and the adult look the same

(only larger)

• All species are primitively wingless

• Silverfish and firebrats

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An Introduction

Ametabolous


An Introduction

Insects with Incomplete

Metamorphosis

• Egg, immature instars (nymphs), adult

• Immature looks like adult but lacks wings

• Wing development external

• Molt of final instar immature leads to winged andreproductively capable adult

• Grasshoppers and relatives, termites, all “bugs,”cockroaches, mayflies, others


An Introduction

Stinkbug

Incomplete Development

Eggs


An Introduction

Nymphs

Adult

Stinkbug

Incomplete Metamorphosis

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An Introduction

Cockroach

Incomplete Development


An Introduction

Insects with Complete

Metamorphosis

• Egg, immature (larva), pupal, adult

• Immature looks nothing like the adult!

• Immatures with distinctive names - caterpillar,grub, maggot, inchworm

• Wing development internal

• Pupal (cocoon) stage between immature andadult

• Beetles, flies, butterflies and moths, bees, ants,wasps,


An Introduction

Housefly

Complete Development

Eggs and larvae

Larvae and pupa


An Introduction

Housefly


Adult

Pupae

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An Introduction

Moth

Holometabolous Development

Oak moth eggs

Oak moth caterpillar


An Introduction

Moth


Pupa

Adult


An Introduction

How Many Arthropods Are

There?

A Good Question!


An Introduction

There are ALOT of Arthropods

Especially Insects

• Species

– Ca. 1 million named species

– Perhaps 10-30 million species in the

world

– Ca. 60% of all species on earth are

insects

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An Introduction

What do Arthropods Do?

Functional “Guilds”

• Primary Consumers - Phytophagous

– 35% of insects eat plants

• Predators/Parasites

– 40% of insects feed on other animals,

especially other insects

• Decomposers

– 25% of insects decompose organic matter


An Introduction

Do Arthropods Have Value?

• As pollinators

• As food

• Providing non-food products

• Providing population control

• Decomposers and Scavengers

• To science and medicine

• To our aesthetic and cultural enrichment


An Introduction

Are Arthropods Detrimental?

• Plant destruction

• Vector plant diseases

• Adverse effects on vertebrates – Direct feeding on living tissue

– Toxic by-products

– Site for secondary infections

– Annoyance and psychosis

– Vectors of disease

– Destruction of fabrics, stored products, andstructures

2Ent 102 Intro Ent

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