Insects in the worldInsects in the world

• Most successful animals• Make up 2 out of three living things• Make up 2 out of three living things• With other arthropods make up over 75% of

all animalsall animals• Have been around for 350 million years

Number of total species

Insects

otherarthropodsarthropodsOtheranimals

Arthropods= Insects and their relativesrelatives

Do not have a backbone(invertebrates)Jointed legged animals include;Jointed legged animals include;Ticks, mites ,spiders ,millipedesCentipedes, and insectsCentipedes, and insects

What is an insect?What is an insect?

Insect -characters Insect -characters

• Body divided into three regions

Insect -characters Insect -characters

• Three sets of legslegs

Easiest character toEasiest character tosee

Insect -characters Insect -characters

• One pair of antennaeantennae

May be May be small <antennae

Insect -characters Insect -characters

• Wings • Only birds, • Only birds,

bats and insects

• Only found in • Only found in adult insects

• Not all insects • Not all insects have wings (fleas,springtails)

Spiders- ArachnidsSpiders- Arachnids

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

MillipedesMillipedes

Insect Developmentor Metamorphosisor Metamorphosis

• Two forms of development (change)(change)

1. Simple/ Partial/ Primitive2. Complete/ Advanced2. Complete/ Advanced

Simple metamorphosisSimple metamorphosis

Egg- nymph- adultAll life stages look similar, behave similarAll life stages look similar, behave similarWhole family can live and feed together

Simple(gradual) Metamorphosis Simple(gradual) Metamorphosis

Simple(gradual) Metamorphosis Simple(gradual) Metamorphosis

Simple Metamorphosis Orders Simple Metamorphosis Orders

Complete MetamorphosisComplete Metamorphosis

• Egg -Larvae-Pupae-Adult• Larvae not look like adult- are wormlike• Larvae not look like adult- are wormlike• Can live in different environment• Can live in different environment• Eat different food• Larvae usually the main pest• Larvae usually the main pest

Complete MetamorphosisComplete Metamorphosis

Complete MetamorphosisComplete Metamorphosis

Complete Metamorphosis OrdersComplete Metamorphosis Orders

Insect LarvaeInsect Larvae

ExoskeletonExoskeleton

Why do insects look so strange?

ExoskeletonExoskeleton

• Insect covered with hard outer shellhard outer shell

• Skin is very plastic like

• Difficult to sense environment

ExoskeletonExoskeleton

MoltingMolting

Cast skin of cicadaCast skin of cicada

< notice slit along back along back

Insect DevelopmentInsect Development

• Cold blooded- development influenced by temperatureinfluenced by temperature

• Most insects inactive below 50 0 F;• Most insects inactive below 50 F;• Breed, eat, develop faster the

warmer it is up to 95 0 F.warmer it is up to 95 0 F.

Insect mouthparts-two typesInsect mouthparts-two types

• Chewing mouthparts

damage

mouthparts

• Sucking damage• Sucking mouthparts

<Piercing,sucking mouth partsmouth parts

Chewing mouthpartsChewing mouthparts

<chewing mouthpartsmouthparts

Chewing mouthpartsChewing mouthparts

<chewing mouthpartsmouthparts

Insect reproductionInsect reproduction

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

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

Insect reproductionInsect reproduction

Experiment

Fruit flies- 2 week life Fruit flies- 2 week life cycle

26 generations/year

100 eggs / female100 eggs / female

Insect ReproductionInsect Reproduction

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

would produce

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

Insect ReproductionInsect Reproduction

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

· Why doesn’t it happen?

Insect classificationInsect classification

• 26-28 Orders -to separate use

• Type of development• Type of development

• Type of mouthparts• Type of mouthpartsandand

Insect classificationInsect classification

If present, number and typeIf present, number and type

Order OrthopteraOrder Orthoptera

• Roaches• Crickets• Crickets• Walking sticks• Mantids• Mantids• Grasshoppers• Grasshoppers

Order OrthopteraOrder Orthoptera

• Simple development• Chewing mouthparts• Chewing mouthparts• Two pairs of wings/• Two pairs of wings/

first set are thickened and leather-like

Orthoptera wingsOrthoptera wings

1st pair leather like, thickened >>

2nd pair thin flying wing2nd pair thin flying wing

Orthoptera wingsOrthoptera wings

Orthoptera Orthoptera

Earwigs- DermapteraEarwigs- Dermaptera

• Short wing covers-second pair not always developeddeveloped

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

America

True bugs -Order HemipteraTrue bugs -Order Hemiptera

•Simple development•Sucking mouthparts•Two pairs of wings/ •Two pairs of wings/

1st pair a half wing in Heterocera

True Bugs- Hemiptera wingsTrue Bugs- Hemiptera wings

< Half wingTwo sets of wings

< half wing< Half wing1st pair thick for

1st half , thin for other

< half wing

1st half , thin for other

Conifer seed bug

Half wing >

Aphids, scales, ciadaSuborder HomopteraSuborder Homoptera

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

Adult cicadaAdult cicada

1

22

Ash leaf-curl aphids

Butterflies and moths -Order Lepidoptera

•Complete development-larvae are caterpillars•Complete development-larvae are caterpillars

•Larvae have chewing mouth parts•Larvae have chewing mouth parts

•Two pairs of wings/ Covered with scales•Two pairs of wings/ Covered with scales

Butterflies and moths -Order Lepidoptera

Scaled wingsScaled wings

Iris borer <true legs caterpillar<true legs caterpillar

<Prolegs with crochetscrochets

Beetles- Order ColeopteraBeetles- Order Coleoptera

•Complete development- larvae are grubs•Complete development- larvae are grubs

•Chewing mouthparts larvae and adults•Chewing mouthparts larvae and adults

•Two pairs of wings-first hardened into

wing covers

Beetles- Order ColeopteraBeetles- Order Coleoptera

Adult beetle

<wing cover

Asian Lady BeetleAsian Lady Beetle

Japanese beetle grubs

< 3 pairs of legs< 3 pairs of legs

True Flies- Order DipteraTrue Flies- Order Diptera

•Complete development-larvae are maggots•Chewing mouthparts in larvae/•Chewing mouthparts in larvae/

variable in adults•Adults only have 1 pair of wings•Adults only have 1 pair of wings

Horse flyHorse fly

< 1 pair of wings< 1 pair of wings

Wing veins

AntennaeAntennae

16,914 species in North America16,914 species in North America113 Families

Rat-tailed maggotsRat-tailed maggots

<larvae have no legs<larvae have no legs

Ants,bees,sawfliesOrder HymenopteraOrder Hymenoptera

•Complete development-larvae are maggot like•Chewing mouthparts in larvae•Chewing mouthparts in larvae•Two pairs of wings- both membrane like

hooked together to work as onehooked together to work as one

Elm sawfly adultElm sawfly adult

Hymenoptera wings Hymenoptera wings

Sawfly larvae

Amazing insect factsAmazing insect facts

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

• Aphids can process 100 times weight in plant sap

• Some insects can • Some insects can survive being frozen solidsolid