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Out of Chaos, Order(s)

2017 Master Gardener College

Erwin ‘Duke’ ElsnerConsumer Horticulture/Small Fruit

Extension Educator

520 W. Front Streetelsner@anr.msu.edu

231-922-4822

Phylum Arthropoda

• Insects and their

relatives

Phylum Arthropoda

• Insects and their

relatives

• Lots and lots

of relatives

Arthropods dominate the planet—by number of species

• Estimates vary, but conservatively:– 6 to 10 million species– Over 80 % of all animal species– 900,000 described species of insects– Millions more undescribed or undiscovered

• United States estimates:– 91,000 insect species described– 73,000 yet to be described– 23,700 beetles– 19,600 flies– 17,500 bees, wasps and ants– 11,500 moths and butterflies

Portions of animal kingdom Portion of all known species

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Time for a little history

• Carolus Linnaeus 1707-1778

• Founder of binomial nomenclature that is the basis of taxonomy

Words and Terms matter

• Nomenclature

• Classification

• Taxonomy

• Systematics

Example of Classification:

ABCDEFGHIJKLMNOPQRSTUVWXYZ

Example of Classification:

ABCDEFGHIJKLMNOPQRSTUVWXYZ

BCDFGHJKLMNPQRSTVWXYZ

AEIOU and sometimes Y

Example of Classification:

ABCDEFGHIJKLMNOPQRSTUVWXYZ

AEFHIKMNTVWXYZ

BCDGJOPRSU

Taxonomy:

• The science of classification; laws and principles covering the classifying of objects

• A system of arranging animals and plants into natural, related groups based on some factor common to each, as structure, embryology, or biochemistry

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Systematics:

The science or a method of classification,

especially taxonomy

• Based on evolutionary principles and lineages

of groups of species

• Representative of true relatedness of species-

– phylogenetics

Ideally

• Taxonomic groupings shouldrepresent the phylogenetic relationships of organisms

Phylogeny:

• The lines of descent or evolutionary development of any plant or animal species

• The origin and evolution of a division, group or race of animals or plants

Reality

• In most cases, the genetic information is not available and groupings are based on observable characteristics

Scientific Names• A “binomial”

• Genus and species

• Unique to each

living organism

• This butterfly is

known as Papilio

glaucus, around the

world, in any

language

Scientific Name Rules

• Genus name always

capitalized

• Species name never

capitalized

• Italicized OR

• Underlined

• Papilio glaucus

• Papilio glaucus

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Species Common Names

• Same common

name may be used

for numerous

species

• Some species have

“official” common

names accepted by

all authorities

• Papilio glaucus =

Eastern Tiger

Swallowtail

Higher Classification

• Groups of related genera placed in “families”

– family Papilionidae contains

• Papilio glaucus

• Papilio canadensis

• Papilio troilus

• Battus philenor

• Eurytides marcellus

–and many more

Higher Classification

• Groups of related families placed in “orders”

– order Lepidoptera contains

• family Papilionidae

• family Saturniidae

• family Tortricidae

• family Noctuidae

• family Pyralidae

–and many more

Higher Classification

• Groups of related orders placed in “classes”

– class Insecta (Hexapoda) contains

• order Lepidoptera

• order Diptera

• order Coleoptera

• order Orthoptera

• order Hymenoptera

–and many more

Higher Classification

• Groups of related classes placed in “phylums”

– phylum Arthropoda contains

• class Insecta

• class Arachnida

• class Diplopoda

• class Chilopoda

• class Malacostraca

–and many more

What Higher Classification Can

Tell You

If you can identify an arthropod to a class:

• You might know if is predatory or not

• Not much more

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What Higher Classification Can

Tell You

If you can identify an arthropod to an order:

• You will know its type of metamorphosis

• You will likely know what type of

mouthparts it has

• You may know if it is predatory or not

What Higher Classification Can

Tell You

If you can identify an arthropod to an order:

• You may know what types of pesticides

might work against it

• You may know its typical habitat

• It will be easier to identify to a family level

What Higher Classification Can

Tell You

• If you can identify to a family:

• class Hexapoda

• class Arachnida

• class Diplopoda

• class Chilopoda

• class Malacostraca

–and many more

Nomenclature:

The system or set of names used in a specific

branch of learning or activity, as in biology for

plants and animals

• Essentially, the rules for naming organisms

Nomenclature – Ending Rules

• Phylums

• Classes

• Orders

• Families

• Genus & species

• No rules

• No rules

• No rules, some patterns

• “idae”

• No rules

• Phylum Arthropoda

Class Insecta

Order Lepidoptera

Family Papilionidae

Genus Papilio

Species glaucus

• The eastern tiger swallowtail

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• Phylum Arthropoda

Class Insecta

Order Homoptera

Family Cicadellidae

Genus Empoasca

Species fabae

• The potato leafhopper

“Splitters” & “Lumpers”

• Authorities

frequently disagree

• Nomenclature and

organization may

vary in references

• Important in real

world??

• Literally dozens of

very similar species

• Minute characteristics

• Mimicry

The Challenge of Identification

• Literally hundreds of

very similar species

• Minute characteristics

• Mimicry

The Challenge of Identification

Which of these two insects would you be willing to capture in your bare hand?

Mistakes are common

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Mistakes are common Mistakes are common

Non migratory mimic Viceroy vs. migrating model Monarch

Basic Characteristics of Arthropods

• segmented bodies

• groups of segments organized into body regions

• jointed appendages

• exoskeleton & molting

• “cold blooded” physiology

• diverse modifications

Arthropod exoskeletons• External protective &

supporting structure

• Varies in thickness, flexibility

• Surface is non-living material

• Must be shed & replaced for growth

Arthropod exoskeletons

• Exoskeleton of immature stages is often thinner

• More flexible, stretchable

• Outer layer is still a dead tissue that must be shed and replaced for growth

Molting• Process of shedding the exoskeleton

• New, larger or modified exoskeleton is formed beneath the old one

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Metamorphosis• A change in form

and/or function as an insect grows and passes through stages

• Change may be minor or substantial, with different names:

– Simple

– Incomplete

– Complete

Gradual or Simple Metamorphosis

• Immature stages outwardly similar to adults

• Details may change as the creature grows and matures

Complete Metamorphosis Arthropod Identification & Classification

• Type of metamorphosis

• Type of mouthparts

• Antennal forms

• Leg characteristics

• Wing type and number

• Many other characters

Classification is based on characteristics

A

r

t

h

r

o

p

o

d

s

Cephalothorax w/4 pairs of legs + abdomen

Chilopoda

Centipedes

Diplopoda

Millipedes

Head w/antennae + elongated trunk w/2 pairs

of legs per segment

Head w/antennae + elongated trunk w/1 pair of

legs per segment

Cephalothorax w/5 pairs of legs, 2 pair

antennae + abdomen

Head w/antennae + thorax w/3 pairs of legs +

abdomen

Malacostraca

Lobsters, shrimp,

sow bugs

Arachnida

Spiders, mites,

ticks

Insecta

Major classes of Athropods

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Class Chilopoda - Centipedes• 2 tagmata, a

cephalothorax & abdomen

• Generally flattened

• Numerous pairs of legs, 1 pair per segment; 1st pair a poison fang

• 1 pair of antennae

• Chewing mouthparts

• predators

Class Chilopoda - Centipedes

Class Diplopoda - Millipedes• 2 tagmata, a

cephalothorax & abdomen

• Generally cylindrical

• Numerous pairs of legs, 2 pair per segment

• 1 pair of antennae

• Chewing mouthparts

• scavengers

Class Diplopoda - Millipedes

Class Malacostraca (Crustacea)

• Crabs, lobsters,

crayfish, sowbugs

• 2 tagmata, a

cephalothorax &

abdomen

• 4 to 7 pairs of legs

• 2 pairs of antennae

Order Isopoda

• Sowbugs, pillbugs

• 2 tagmata, a

cephalothorax &

abdomen

– But hard to discern

the division point

• 7 pairs of legs

• Omnivorous scavengers

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Class Arachnida• 2 tagmata, a

cephalothorax &

abdomen

• 4 pairs of walking

legs

• No antennae

• Chelicerate

mouthparts

• Spiders, ticks, mites

Arachnida Morphology• Two body parts: Cephalothorax and Abdomen

Arachnida Morphology• Mites and Ticks - hard to discern the

cephalothorax from the abdomen

Spiders, order Araneae

Spiders, order Araneae• Many families, hard to key out

• Mostly generalists, some are searchers

• Kill prey with venom

• Some kill prey larger than themselves

• Some use silk for capturing prey

Order Opiliones - Harvestmen

• 2 tagmata, a

cephalothorax &

abdomen,

appearing fused

• 4 pairs of walking

legs

• No antennae

• Minor predators &

scavengers

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Arthropod Orders: Acari

• Mites and ticks– Chelicerate mouthparts (diff. form of piercing-sucking)– Gradual metamorphosis– 4 pairs of walking legs (1st stage has 3 pair) – No antennae, no wings– Body divisions not obvious, a cephalothorax and

abdomen

Order Scorpiones

Order Pseudoscorpiones Class Insecta (Hexapoda)

• 3 body regions,

– head, thorax & abdomen

• 0-3 pairs of jointed legs

• Some species with

wings

• 1 pair of antennae

• Mouthparts modified in

various ways

• Incredibly diverse and “successful”

Insect Morphology• Three body parts: Head, thorax and Abdomen

Insect Morphology• Three body parts: Head, thorax and Abdomen

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Basic Insect Morphology Exercise 1

• Hand lens technique

• Sort your arthropods to class level

• See if you can sort Arachnids to order level

Class Insecta (Hexapoda)

• 3 body regions,

– head, thorax & abdomen

• 0-3 pairs of jointed legs

• Some species with

wings

• 1 pair of antennae

• Mouthparts modified in

various ways

• Incredibly diverse and “successful”

Shrimps,

Crabs &

Sow bugs

Diptera

Lepidoptera

Hymenoptera

Coleoptera

Hemiptera

Homoptera

Plus 21 more!

Arthropods

Flies

Beetles

Insects

Spiders,

mites,

ticks &

Scorpions

Centipedes Millipedes

Moths

Bees, Wasps

Plant bugs

Aphids

Orthoptera, Dermaptera, Isoptera, Thysanoptera . . . . .

Basic Insect Morphology Basic Insect Morphology

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Insect Morphology• Three body parts: Head, thorax and Abdomen

Parts of the head

Head features

• Mouthparts

• Antennae

• Eyes

Types of mouthparts

Chewing

Piercing/sucking

Sponging/lapping

Siphoning

Chewing Mouthparts• Opposable jaws called mandibles

• Several accessory parts for food manipulation

Piercing-Sucking Mouthparts

• Delicate stylets in a sheath (proboscis)

• Ingests only fluids

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Mouthparts – Piercing/Sucking Piercing-Sucking Mouthparts

• Proboscis may tuck under head or thorax when not in use

Sponging/Lapping Mouthparts

• Ingests only fluids

Siphoning Mouthparts

• Ingests only fluids

• Coiled when not in use

Antennae

• Sensory functions

• Vary widely in form and size

Compound Eyes

• Dozens to thousands of facets

• Some species can detect ultra-violet wavelengths

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Ocelli

• Only type of eyes on many caterpillars

Thorax features

• Three pairs of jointed legs on the thorax

–Many modifications of form and function

Leg Modifications• Raptorial• Jumping

• Digging

Thorax features• Two pairs of wings

on thorax of adults of most species

– Front pair thickened or leathery in many groups

– Detail of wings very important for identification

Wings Wing venation aids in ID

• Wings may be:

– Membranous

– Leathery

– Hard

– Hairy

– Scale covered

– Foldable

– Brachypterous

– Vestigial

– Absent

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Abdomen features

• Often hidden under wings on adults

• Segmentation often visible

• Terminal segments modified for mating and egg laying functions

• May bear “false” legs on immature stages

Insect Stages, Growth & Development

• Insects typically:

Lay eggs

Pass through several immature stages

Mate after reaching adulthood

Gradual or Simple Metamorphosis

• Immatures are called nymphs

• Nymphs similar to adults

• Wings develop externally

• Same type of mouthparts through all active stages

Gradual Metamorphosis

• Developing wings appear as small projections from the thorax, enlarging at molts

• Wings are not fully developed or functional until the adult stage

nymph

nymph

adult

eggs

Incomplete Metamorphosis

• Most groups with this form of metamorphosis are aquatic

• Nymphs and adults somewhat different in appearance

• Nymphs have gills

• Adults are terrestrial with tracheal systems

Complete Metamorphosis• Young stages may be

very different from adults

• Early stages are called “larvae”

• “Pupal” stage between larval and adult stage

• Wings develop internally until pupal stage

• Mouthparts change type in some orders

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Complete Metamorphosis

larval stages

pupa

(in cocoon)

adult

eggs

Types of Larvae

Types of Pupae Very common misconception

Common Orders of InsectsOrder Common Name Metamorphosis Mouthparts Wings

Orthoptera grasshoppers, gradual chewing 2 pair

crickets

Mantodea mantids gradual chewing 2 pair

Dermaptera earwigs gradual chewing 2 pair

Isoptera termites gradual chewing 2 pair

Hemiptera bugs, hoppers, gradual piercing-sucking 2 pair

aphids, scales

Common Orders of InsectsOrder Common Name Metamorphosis Mouthparts Wings

Coleoptera beetles, weevils complete chewing 2 pair

Neuroptera lacewings complete chewing 2 pair

Hymenoptera bees, ants, complete chewing 2 pair

wasps

Lepidoptera moths, complete chewing/ 2 pair

butterflies siphoning

Diptera flies complete chewing/ 1 pair

piercing-sucking

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Insect Orders: Orthoptera

• Grasshoppers, crickets, katydids– Chewing mouthparts; adults and nymphs damaging – Gradual metamorphosis– Forewings are elongate, narrow, and somewhat

thickened; hindwings are membranous with extensive folded area.

– Hind legs often enlarged for jumping– Immature stages (nymphs) resemble wingless adults

Insect Orders: Mantodea

• Praying mantids– Chewing mouthparts; adults and nymphs damaging – Gradual metamorphosis– Forewings are elongate, narrow, and somewhat

thickened; hindwings are membranous with extensive folded area.

– Raptorial front legs– Immature stages (nymphs) resemble wingless adults

Insect Orders: Hemiptera

• True bugs– Piercing-sucking mouthparts– Gradual metamorphosis– “Half-wing” - front wing is thick at base, membranous at

tip– Antennae of five or more segments, long and conspicuous

or short and concealed– Immature insects are similar to the adult but wings are

incomplete or absent

Insect Orders: Homoptera(now joined into Hemiptera)

• Aphids, leafhoppers, cicadas, whiteflies, scales– Piercing-sucking mouthparts

– Gradual metamorphosis

– Adults are winged or wingless; when present, hind wing is shorter than the front wing

– Immature stages usually similar to adult but wingless

– Serious pests of cultivated plants and sometimes vectors of plant diseases

Insect Orders: Thysanoptera

• Thrips– Modified piercing-sucking mouthparts; adults and nymphs

damaging

– Gradual metamorphosis

– Wings are like sticks with long hairs

– Immature stages (nymphs) resemble wingless adults

– Some disease vector relationships

Insect Orders: Neuroptera

• Lacewings, antlions, snakeflies, mantispids, dobsonflies, dustywings, alderflies

– Insect predators; many are aquatic

– Two pairs of similar-sized wings

– Chewing mouthparts

– Complete metamorphosis

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Insect Orders: Coleoptera

• Beetles and weevils– Chewing mouthparts on adults and immatures

– Complete metamorphosis

– Front wings (elytra) hardened, shell-like

– Adults usually have noticeable antennae

– Larvae have head capsules, usually three pairs of legs on the thorax and no legs on the abdomen

Insect Orders: Lepidoptera

• Butterflies and moths– Chewing mouthparts on larvae, siphoning on

adults– Complete metamorphosis– Wings covered with colored scales– Adults usually have noticeable antennae– Larvae have head capsules, usually three pairs of

legs on the thorax and prolegs on the abdomen

Insect Orders: Hymenoptera

• Sawflies, bees, wasps & ants– Chewing mouthparts on larvae & adults

– Complete metamorphosis

– Two pair of membranous wings on adults

– Adults usually have noticeable antennae

– Many adults bear stingers

– Larvae in two main forms – caterpillar-like or grubs with head capsules

Insect Orders: Diptera

• Flies & Mosquitoes

– Larvae with “chewing” mouthparts, adults with piercing-sucking or sponging mouthparts

– Complete metamorphosis

– Adults with one pair of membranous wings

– Larvae with no legs on thorax or abdomen

– Rather soft-bodied or slightly hardened adults

Exercise 2

• Sort your insects to order level

Identification Keys

• Dichotomous

keys

• Picture keys

• Word keys

• Combinations

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Picture Keys Picture Keys

Word Keys

• Must be read with utmost attention to detail

• Mark choices with pencil or sticky notes

Dichotomous Keys

• Most combine word “couplets” and

figures when needed to clarify

descriptions

Key:

• An arrangement or listing of the significant characteristics of a group of organisms, used as a guide for taxonomic identification

Taxonomic Key:

• Taxonomic keys are like a flow chart, consisting of a series of decision point at which the user has to compare specimens to descriptions, figures or pictures to decide what “path” to follow

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Taxonomic Key:

• Taxonomic keys are like a flow chart, consisting of a series of decision points at which the user has to compare specimens to descriptions, figures or pictures to decide what “path” to follow

• The path does not necessarily follow lines of relation or phylogeny

• A key constructed so that at each decision point there are only two options

Dichotomous Key:

Wings are presentYes No

Front wings thickenedYes No

More than 6 legsYes No

That’s all,

folks!

Erwin ‘Duke’ ElsnerSmall Fruit EducatorMSU Extension520 W. Front Streetelsner@anr.msu.edu231-922-4822