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