Phylum Arthropoda

Read Chap 31 pgs. 681-703 Dichotomous Key

The study of insects (and their near relatives).

What is Entomology?

PLANTSPLANTS

OTHEROTHERANIMALSANIMALS

OTHEROTHERARTHROPODSARTHROPODS

INSECTSINSECTS

Species Diversity

Arthropods

Jointed-legged invertebrates

CLASSIFICATION (LEARN EXAMPLES OF EACH CLASS)

SUB- Trilobita Crustacea Chelicerata Uniramia PHYLUM CLASS extinct Crustacea Arachnida

Chilopoda

Diplopoda Insecta ORDER 16

- Segmented bodies are arranged into regions, called tagmata (in insects = head, thorax, abdomen).

- Paired appendages (e.g., legs, antennae, wings) are jointed.

- Possess chitinous exoskeleton that must be shed during growth.

- Open circulatory system

- Nervous system is ventral (belly) and the circulatory system is open and dorsal (back).

- Complete digestive system

Characteristics of Phylum Arthropoda

Head Thorax Abdomen

Exoskeleton

Major reason for success!Provides

Support Protection Prevention of dehydration Sites for muscle attachment

Metamorphosis

Change body form from immature (larval) stages to adult forms

Reduces competition between stages for Food Living space

Taxonomy of Arthropods

4 subphylaTrilobitomorpha (all extinct)ChelicerataCrustacea Uniramia

The state fossil of Ohio

Subphylum Chelicerata (plier like)

Horseshoe crabsSpidersMitesTicksScorpions

Scorpion

Scorpion Anatomy

chelicerae eyes pedipalp

Scorpion Head

ScorpionTick(a mite)

Pseudoscorpion

Daddy-long-legs

WolfSpider

Orders of Arachnids

Pseudo scorpion(pseudo means “false”)

pedipalps &chelicerae

cephalothorax

abdomen

Mite and Tick Body Regions

American dog tick male-VectorsRocky mountain spotted fever

Blacklegged (deer) tick female- Vectors Lyme disease

Common ticks

American dog tick female laying egg mass (1000-2000 eggs!).

Clover mites

Twospotted spider mites

Predatory mite

Mites

Velvet mite

cephalothorax abdomen

Phalanges (daddy-long-legs)

pedipalp

chelicera (fang)

cephalothorax

abdomen

narrow waist

Spider Anatomy

Abdomen

Pedipalp

Chelicera (fang)

Cephalothorax

Jumping Spider

Wolf spider with egg case Spitting spider

Tarantula Orbweaving spider

Black widow with egg case

Brown recluse (fiddleback)

Dangerous Spiders

Interesting modifications

Spinnerets Malpighian tubules

Subphylum Crustacea

Shrimp, lobsters, crayfishFairy shrimp, brine shrimpWater fleasBarnacles

Crayfish cephalothorax(Decapoda)

Sow bug (Isopoda), a terrestrial crustacean

Crustaceans

CLASS CRUSTACEA tremendous variety

daphnia, crabs, lobster, pill bugs, crayfish *primarily aquatic, mostly marine 25,000

species (motile sessile microscopic, 2 ft. or more) *gills, at least 5 pairs of legs *carapace- shield to protect vital organs * branched antennae see lab for specifics of this group

Subphylum Uniramia

Class Diplopoda (millipedes)Class Chilopoda (centipedes)Class Hexapoda (insects)

Diplopod (Millipede)

Two pair of legs per visible segment, attached under body.

Symphyla (Symphyla)[garden centipede]

No fangs, no eyes, legs attached to side of body.

[one pair of antennae, head & trunk regions, trunk with many pairs of legs]

Pair of fangs under head, one pair legs per visible segment - attached to side of body.

Chilopod (Centipede)

Millipede (Diplopoda)

Centipede (Chilopoda)

Garden centipede (Symphyla)

Nervous SystemJohnston’s organs (hearing - on antennae)Tympanic organs (hearing – on legs or

body)Compound eyes (facets – ommatidia –

fused)Simple eyes (ocelli)

Economic Impact of Arthropods

1. Name two effects of each major group has on mankind (good and bad).

Crustacea, Millipede, Centipede, Arachnida

2. For insects, list 4 good things that they do and 4 bad things that they are responsible for.

Insects

Head Thorax Abdomen

• 1,000,0001,000,000 species known species known Possibly 3,000,000 unidentified

species

How Many Kinds Insects are there in the world?

Classification of Japanese Beetle

Kingdom Animalia Phylum Arthropoda Class Insecta Order Coleoptera Family Scarabaeidae Genus Popillia Species japonica

hormone induced changes to create new and larger exoskeleton

desiccation potential "instars" periods between molts vulnerable while exchanging skeletonmay continue throughout life or end at a

particular point

*molting "ecdysiast"-

DIGESTION

foregut ingestion, mechanical breakdown and

storagemidgut chemical digestion, absorption, enzymatic, (sounds like our intestines)hindgut absorption of water and formation of feces

RESPIRATION (handout in binder )

Open Circulatory System- blood not confined to the vessels Pericardial sinus- space for gas exchange around

the heart (open space) Gases into the body through the spiracles in the

exoskeleton (waxy) Trachae- tubes from spiracles to vital locations ***blood is not vital for gas exchange*** rare to

find hemoglobin Tracheoles- branches with membranes at the end

fluid tipped perhaps

other possible modifications

*book lungs- look like corrugated cardboard *coordination between opening and closing of

spiracles to pump the air in (think of a tire pump) *air sacs at the end of the tracheoles for increased

surface area *gills

BEHAVIOR IN THE PHYLUM ARTHROPODA

(insects mostly) video Swarming Hordes Communication Chemical, visual, and auditory

Communication

*chemicalPheromones- airborne chemicals are used by

males can find females for mating purposes 1) releasers- immediate behavior

change 2) primers- profound physiological

changes Bug’s Life

humans have exploited this with bug traps (June bugs)

Scent trails can be left on the ground during food foraging trips (A BUG’S Life video)

plants mimic scents to attract pollinatorsdeath pheromones- remove ant from a

colony and paint with the chemical, return to colony and is repeatedly carried away.

0.00000001 grams silkworm female can be detected 2 miles

Communication

*visual- can see ultraviolet wavelengths of light Fireflies use light to attract mates Males are

in the air while females remain on the ground

Communication

*Sound production in grasshoppers, crickets and

cicadas scraping of limbs on the exoskeleton, air

vibrations along the exoskeleton caused by muscle movement

Mimicry

visual, camouflage (hide or lie in ambush) SOUNDS CAN ALSO BE MIMICED (faked you out!) Now you’re dinner!

SOCIAL BEHAVIOR requires communication

A colony can have the same effect as a large single animal

Hey, hey, hey do what I tell you

Division of Labor ex. bee hive 80,000 members polymorphic anatomy Drone Worker Queen

What a life?

worker 6 wk. life, sterile female, reproductive organs become stinger, 1,000 s

drone- (n) reproductive male, only for mating, 100s, die after mating, killed if food is low

queen bee- reproductive female, 5-6 year life

worker behavior

week 1 feed queen, drones, larva, secrete "royal

jelly" weeks 2-4 secrete wax, clean, repair hive, guard, fan in fresh air weeks 5-6 gather pollen and nectar

Stand for the QUEEN!

QUEEN is like other female but she eats "ROYAL JELLY"

Secretes "queen factor" which prevents other females from becoming reproductive. Mates once and stores sperm

Butt wiggle dance

Metamorphosis

Incomplete- grasshopper and termite Egg- nymph- adult Immature adult look alike,

small ,non-sexual

Metamorphosis

Complete butterfly, moth (most insects) Egg-larva-pupa- adult CACOON OR CHRYSALSIS

Controlling factors Sequential expression of genes Brain hormone stimulates molting hormone

in thorax gland

Molting hormone released in both where juvenile hormone is present

JH MH larva molts JH MH larva pupates JH MH pupa to adult

Importance of metamorphosis? No competition for food What the caterpillar eats the adult does not

Name ________________________ Period ________ CRAYFISH EVALUATION LAB Materials 1 lab set “Dissecting a Crustacean- the Crayfish” Dissecting microscope Dissecting tools STEP 1 Examine the external anatomy of a crayfish Follow Procedure A of the LAB NOT STEP 5 ON LIVE CRAYFISH Compare the live specimens w/ diagrams on sheets Describe texture of the crayfish STEP 2 Test Crayfish Behavior Lay live crayfish in a clear plastic container Observe/record behavior for 4-5 minutes Observe/record movements (O/R) O/R responses to stimuli on a table with 2 columns (see below)

Bubbles gently blown into the water Touch with a probe (Anterior/ Posterior) Touch chelipeds, walking legs, middle of dorsal, telson Darken ½ of the container Shine a light on the anterior

5. Drop one piece of food (shrimp pellet) near the anterior O/R feeding behavior STEP 3 Crayfish Dissection Follow instructions in the lab papers. STEP 4 Reading Assignments 715-719, 720-734 EXAMPLE Stimulus Response Probe telson walking leg

Rules for writing a dichotomous key

1. always couplets 2. total number of couplets is one less than

the total number of items 3. no overlapping measurements 4. only physical descriptions (no behaviors) 5. start couplets with the same word

Test Topics Dichotomous Key, Video “Swarming Hordes”,

Arthropod Notes, Lab Crayfish dissection and Behavior, Insect

Social Behavior, SEQUENTIAL COMPARISON INDEX,

relationship between annelids and arthropods, Read (general 715-719, crustacea729-734) Chap 31 in regular BIOLOGY text