Photo by Joel Trick

Insects in the world

• Most successful animals

• Make up 2 out of three living things

• With other arthropods make up over 75% of all animals

• Have been around for 350 million years

Insects

otherarthropodsOtheranimals

Number of total species

Arthropods= Insects and their relatives

Do not have a backbone(invertebrates)

Jointed legged animals include;

Ticks, mites ,spiders ,millipedes

Centipedes, and insects

What is an insect?

Insect -characters

• Body divided into three

regions

Insect -characters

• Three sets of legs

Easiest character to

see

Insect -characters

• One pair of antennae

May be small

<antennae

Insect -characters

• Wings • Only birds,

bats and insects

• Only found in adult insects

• Not all insects have wings (fleas,springtails)

Spiders- Arachnids

• 4 pairs of legs• No antennae• No wings• 2 body divisions• Spiders are not

insects

Millipedes

Insect Developmentor Metamorphosis

• Two forms of development (change)

1. Simple/ Partial/ Primitive

2. Complete/ Advanced

Simple metamorphosis

Egg- nymph- adultAll life stages look similar, behave similar

Whole family can live and feed together

Simple(gradual) Metamorphosis

Simple Metamorphosis Orders

Complete Metamorphosis

• Egg -Larvae-Pupae-Adult• Larvae not look like adult- are wormlike

• Can live in different environment

• Eat different food

• Larvae usually the main pest

Complete Metamorphosis

Complete Metamorphosis

Complete Metamorphosis Orders

Insect Larvae

Exoskeleton

Why do insects look so strange?

Exoskeleton

• Insect covered with hard outer shell

• Skin is very plastic like

• Difficult to sense environment

Exoskeleton

Molting

Cast skin of cicada

< notice slit along back

Insect Development

• Cold blooded- development influenced by temperature

• Most insects inactive below 50 0 F;

• Breed, eat, develop faster the warmer it is up to 95 0 F.

Insect mouthparts-two types

• Chewing mouthparts

• Sucking mouthparts

damage

damage

<Piercing,sucking mouth parts

Chewing mouthparts

<chewing mouthparts

Chewing mouthparts

<chewing mouthparts

Insect reproduction

1. Short life cycles- most go through generation in 1- 6 weeks

2. Large number of offspring / female -100-2,000 eggs

Insect reproduction

Fruit flies- 2 week life cycle

26 generations/year

100 eggs / female

Experiment

Insect Reproduction

In 1 year from 1 male and 1 female if all offspring survive to breed

would produce

10 41 flies- if pack 1000 flies/cu. in.

Insect Reproduction

A ball of fruit flies 96 million miles in diameter which is 2/3 of the distance from earth to sun

· Why doesn’t it happen?

Insect classification

• 26-28 Orders -to separate use

• Type of development

• Type of mouthparts

and

Insect classification

If present, number and type

Order Orthoptera

• Roaches

• Crickets

• Walking sticks

• Mantids

• Grasshoppers

Order Orthoptera

• Simple development

• Chewing mouthparts

• Two pairs of wings/

first set are thickened and leather-like

1st pair leather like, thickened >

2nd pair thin flying wing

Orthoptera wings

Orthoptera wings

Orthoptera

Earwigs- Dermaptera

• Short wing covers-second pair not always developed

• Simple development• Chewing mouthparts• Have terminal forceps• 20 species in North

America

True bugs -Order Hemiptera

•Simple development•Sucking mouthparts•Two pairs of wings/ 1st pair a half wing in Heterocera

< Half wing

True Bugs- Hemiptera wings

Two sets of wings

1st pair thick for

1st half , thin for other

< half wing

Half wing >

Conifer seed bug

Aphids, scales, ciadaSuborder Homoptera

•Simple development•Sucking mouthparts•Two pairs of membrane type wings

Adult cicada

1

2

Ash leaf-curl aphids

Butterflies and moths -Order Lepidoptera

•Complete development-larvae are caterpillars

•Larvae have chewing mouth parts

•Two pairs of wings/ Covered with scales

Butterflies and moths -Order Lepidoptera

Scaled wings

Iris borer <true legs

<Prolegs with crochets

caterpillar

Beetles- Order Coleoptera

•Complete development- larvae are grubs

•Chewing mouthparts larvae and adults

•Two pairs of wings-first hardened into

wing covers

Beetles- Order Coleoptera

Adult beetle

<wing cover

Asian Lady Beetle

Japanese beetle grubs

< 3 pairs of legs

True Flies- Order Diptera

•Complete development-larvae are maggots•Chewing mouthparts in larvae/ variable in adults•Adults only have 1 pair of wings

Horse fly

< 1 pair of wings

Wing veins

Antennae

16,914 species in North America113 Families

Rat-tailed maggots

<larvae have no legs

Ants,bees,sawfliesOrder Hymenoptera

•Complete development-larvae are maggot like•Chewing mouthparts in larvae•Two pairs of wings- both membrane like hooked together to work as one

Elm sawfly adult

Hymenoptera wings

Sawfly larvae

Amazing insect facts

• Larvae eat 3-4 times their weight / day in food

• Aphids can process 100 times weight in plant sap

• Some insects can survive being frozen solid

Photo by Joel Trick

Multi colored Asian Lady Beetle

Harmonia larvae

Cocinellid beetles