Arthro- means jointed Pod – means foot or feet Jointed feet. Arthropods Arthro- means jointed Pod – means foot or feet Jointed feet.

Number of species Mollusca Chordata Platyhelminthes Nematoda Arthropoda Porifera Annelida Echinodermata Sarcomastigophora Apicomplex Ciliophora

Arthropods Most Successful Animals Number of species Diversity Distribution Longevity

Reasons for Success Versatile exoskeleton Segmentation Oxygen piped directly to cells (terrestrial) Highly developed sensory organs Complex behavior Metamorphosis

Characteristics of Arthropods Have segmented bodies that are bilaterally symmetrical Have an exoskeleton – hard covering on the outside of their body made of chitin Have many appendages – any structure such as an arm or leg that grows out of the body of an animal Respiratory organs are either gills, tracheal tubes or book lungs

5. Have many sense organs such as antennae that can detect movement, sound or chemicals 6. Well developed nervous systems Most have either simple or compound eyes. Some have both What are some disadvantages of an exoskeleton? (Think what it would be like to have a tough armor on the outside of your body.)

Disadvantages of an exoskeleton Heavy Must be shed for growth to occur. Shedding of an exoskeleton is called molting. Can be easier for predators to attack before new exoskeleton hardens Not flexible (why jointed appendages are so important

5 classes of arthropods Class Arachnida – spiders, scorpions and mites (chiggers and mange) Class Crustacea – shrimp, lobsters, crayfish, pill bugs (rolly polly) Class Insecta – flies, grasshoppers, beetles Class Chilopoda – centipedes Class Diplopoda -- millipedes

Class Crustacea mostly marine, fresh water, a few terrestrial all have two pair of antennae, some have antennules that are used for balance five or more pairs of legs segmented abdominal appendages head & trunk fused into a cephalothorax & abdomen body arrangement have gills 9

Sowbugs or pillbugs (rolly polly) only terrestrial crustacean Sand fleas Barnacles Crabs, lobster, shrimp

Crayfish cephalothorax (Decapoda) Sowbug (Isopoda), a terrestrial crustacean 11

Two pair of antennae Biramous appendages

Fig. 19.3

Fig. 19.1

Fig. 19.5 Fig. 19.5

Crayfish

Fig. 19.2a

Fig. 19.2b

Fig. 19.6

Fig. 19.7 Fig. 19.7

Lobster

Shrimp

Crab

Pill Bug

Fig. 19.15c

Fig. 19.16c

Orders of Arachnids Scorpions Pseudoscorpions Daddy Long-Legs Mites & Ticks Spiders 33

Pseudoscorpion Tick (a mite) Scorpion Wolf Spider Daddy-long-legs 34

Scorpion Anatomy 35

36

chelicerae eyes pedipalp 37

Pseudoscorpion 38

Mite and Tick Body Regions pedipalps & chelicerae cephalothorax abdomen 39

Blacklegged (deer) tick female American dog tick male Blacklegged (deer) tick female 40

American dog tick female laying egg mass (1000-2000 eggs!). 41

Twospotted spider mites Clover mites Twospotted spider mites Predatory mite 42

daddy long-legs cephalothorax abdomen 43

Spider Anatomy pedipalp chelicera (fang) cephalothorax narrow waist abdomen 44

Jumping Spider Abdomen Cephalothorax Chelicera (fang) Pedipalp 45

World’s Largest Spiders https://www.youtube.com/watch?v=_POy748DVyk

Wolf spider with egg case Spitting spider Orb-weaving spider Tarantula 47

Black widow with egg case Brown recluse 48

Class Arachnida 4 pair of legs Have pedipalps – 2nd pair of appendages used in gathering food and other functions 2 body segments called cephalothorax and abdomen Except mites & ticks Most are predators Inject enzymes into prey Suck fluid into pharynx Have 8 eyes -- a combination of simple and compound eyes

Arachnid Body Regions Cephalothorax Abdomen

Order Scorpionida Large pedipalps Abdominal stinger Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Order Scorpionida Large pedipalps Abdominal stinger Photo (a) © SS#11/PhotoDisc

Order Araneae Spiders Fangs with poison glands Silk glands

Fig. 18.4

Fig. 18.5

Respiratory structures Arachnid respiratory structure is Book lung or Spiracles – tiny holes on the abdomen that open and close allowing air to come in and flow over a series of tubes called trachae.

Copyright © The McGraw-Hill Companies, Inc Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Dugesiella Tarantula

Latrodectus mactans Black widow spider Neurotoxin

Loxosceles reclusa Fiddle back spider Necrotoxin Brown recluse Brown Violin Necrotoxin

Loxosceles reclusa Necrosis of tissue

Day 3

Day 4

Day 5

Day 6

Day 9

Day 10

Order Acari Ticks Mites Body segments fused

Rocky Mountain Spotted Fever Ticks are vector High fever Headache Muscle pain Rash BEGINS ON EXTREMETIES 25% fatal without antibiotics

Dermacentor variabilis Dog tick Dermacentor andersoni Wood tick

Fig. 18.16

Dermatophagoides Dust mite Allergies to fecal products 1 gram of dust holds 250,000 droppings

Trombicula Chigger mite Larva feed on skin Dermatitis

Class Chilopoda Centipedes One pair of legs per body segment Poison fang and claws Flattened bodies Carnivores

Class Diplopoda milliipedes Two pair of appendages per body segment Cylindrical body Herbivores Have stink glands for protection

Rule of 3s 3 pairs of legs 3 body segments : head, thorax, abdomen 1 pair of antennae

Class Insecta Two types of metamorphosis: 1. Complete Egg larva pupaadult 2. Incomplete Eggnymphadult A nymph is a minature adult that must molt several times before becoming an adult

Complete Metamorphosis egg larvae pupa adult

Complete Metamorphosis Four stages that all look different

Incomplete Metamorphosis egg nymphs adult

INCOMPLETE METAMORPHOUS Insects change shape gradually!

Insects with Complete Metamorphosis EGG  LARVA  PUPA  ADULT Coleoptera (beetles) Hymenoptera (bees, ants, wasps) Diptera (flies) Lepidoptera (butterflies)

Insects with Incomplete Metamorphosis EGG  NYMPH  ADULT Siphonaptera (fleas) Isoptera (termites) Orthoptera (grasshoppers & crickets) Hemiptera (true bugs) Homoptera (cicadas & hoppers) Wings NOT fully developed

There are ALWAYS SIX legs, and they are attached to the THORAX Count the Legs! There are ALWAYS SIX legs, and they are attached to the THORAX

Antenna One Pair on head Jointed Sensory (smell) Called “feelers” Filiform most common shape (segments = size) May be modified FILIFORM

Antenna Modifications

Wings or No Wings Most adults have 2 pairs Called forewings and hindwings Some insects are wingless (silverfish, fleas, some termites and ants)

A network of Veins strengthens wings MEMBRANEOUS (clear) WINGS More on Wings A network of Veins strengthens wings MEMBRANEOUS (clear) WINGS

Some Wings Are Covered With Powdery Scales BUTTERFLIES & MOTHS

Wings May Be Modified Order Diptera (flies) 2nd pair of wings modified into HALTERES Used for balance Makes flies hard to catch!

Beetle Wings Meet in straight line down the abdomen ELYTRA Hard Forewing called Elytra Meet in straight line down the abdomen Membranous hindwings folded underneath (flight)

INSECT ORDERS INSECTS WITH WINGS

Why Can’t I Call All of Them Bugs? EVERY BUG is an insect, but NOT ALL INSECTS are bugs! True BUGS are in the Order HEMIPTERA Posterior thorax is triangular; called SCUTELLUM Last 3rd of wing CLEAR

Which of these are BUGS? ALL

More Hemipterans Assassin Bug Water Boatman Giant Water Bug Leaf Hopper

Coleoptera Called beetles Tough exoskeleton Forewings called Elytra Fly with membranous hindwings Larva called grubs Cucumber beetle Ladybird beetle Rhinoceros beetle

Ephemeroptera Called Mayflies Juveniles are aquatic; called naiads Adults found near water & don’t feed Adults reproduce & die in 24 hours Soft bodies with 2 long Ceri (tail fibers) ADULT NAIAD

Diptera Contains mosquitoes & flies One pair functional wings Club-shaped halteres for balance Bodies often hairy Green Bottle fly Hover Fly Fruit Fly Aedes Mosquito

EARWIG EATING CATERPILLAR Dermaptera Called earwigs Long, flat bodies Forceps (pincers) on end of abdomen Short, hard forewings (membranous wings folded underneath Large jaws (mandibles) on head PINCERS EARWIG EATING CATERPILLAR

Orthoptera Grasshoppers, locusts, crickets, katydids Very long bodies Rear legs modified for jumping Females with egg laying tube (ovipositor on end of abdomen) Often communicate with chirping sounds

Lepidoptera Moths, butterflies, & skippers Siphoning mouthparts coiled under head Powdery scales on wings Butterflies fold wings flat above body at rest Moths are night active Important plant pollinators

Neuroptera Lacewings Net veined wings Small, delicate insects Long antenna Predators on other insects May feed on nectar

Thysanoptera Thrips Two pairs of fringed wings Feed on plant sap

Isoptera Termites Live in colonies Feed on wood Soft bodies & short antenna Castes – workers, soldiers, kings, and queen

Mecoptera Scorpion flies Last abdominal segments curved like scorpion Two pairs of narrow wings Head elongated into a beak (rostrum) Long antenna

Homoptera Cicadas, leaf hoppers, wingless aphids If wings present, held roof like over body & membranous Piercing-sucking mouthparts Cicada Leafhopper

Odonata Dragonflies & damselflies Dragonflies hold clear wings spread perpendicular to body at rest Damselflies hold clear wings together over abdomen

Plecoptera Stoneflies Aquatic nymphs Aerial adults are short lived Make drumming sound to find mates

Hymenoptera Bees, ants, wasps Narrow waist connects thorax & abdomen Abdomen curved downward May have stinger on end of abdomen Carpenter bee Red ant Yellow jacket

INSECT ORDERS WINGLESS INSECTS

Thysanura Called Silverfish Found around houses or outside under stones or wood Fast runners Damage books Secretive and active at night. Flat, long bodies Long antennae Three, long, tail like appendages

Siphonaptera Fleas Ectoparasites Bodies laterally compressed Enlarged hind jumping legs Very short antenna

Collembola Called springtails Small & soft bodied Furcula (jumping mechanism) on abdomen Furcula folds under the body at rest Found in decaying plant material

Anoplura Sucking lice Parasites of mammals Very small Head and body lice are examples Attracted to children’s fine hair Carry disease

Mallophaga Biting lice External parasites on birds & mammals Broad head & flattened body Feed on dead skin, feathers, and fur