PHYLUM - ARTHROPODA (Arthropoda = " ....................... feet")

More than 85% of all animals are arthropods (over 1,000,000 species).

Characteristics:

1. ............................ legs

2. ............................ bodies

3. External skeletons (made of ....................)

4. ............................ hearts

5. ............................ nerve cords

Classes:

• ................................ - spiders, mites, ticks, scorpions
• ................................ - crayfish, lobsters, crabs
• ................................ - centipedes
• ............................... - millipedes
• ................................ - insects

Class	Legs	Body Sections	Examples
Arachnida	8	2	Spiders, Mites, Ticks, Scorpions
Crustacea	10	2	Crayfish, Lobsters, Crabs
Chilopoda	1 pair per segment	Varies	Centipedes
Diplopoda	2 pairs per segment	Varies	Millipedes
Insecta	6	3	Flies, Grasshoppers, Etc.

Class - Arachnida

Characteristics:

1. Two body segments

• ..................... (head and chest area)
• ....................

2. .................... legs

3. .................... eyes (have only 1 lens in each eye)

4. ....................... - claw-like poison fangs

SPIDERS

Spiders are the most familiar of the arachnids.

Spiders are beneficial to man because of the insects that they eat.

Spiders have sensory setae all over their body, eight simple eyes, & no antennae.

Other structures:

• ................................. - breathing pores in the exoskeleton
• ................................. - breathing tubes that carry oxygen from the spiracles to the lungs
• ................................. - special lungs with thin tissues resembling the pages of a book
• ................................. - special organs that produce a strong elastic protein that hardens upon contact with air forming spider silk. Webs may be used to capture prey or form nests. Not all spiders spin webs.

Young spiders may use long strands of spider silk to carry them through the air. This is called

............................

............................... - remove nitrogen (cell) wastes from the blood (similar to flame cells and nephridia)

Spiders feed by injecting digestive enzymes into their prey and sucking out the juices, or by regurgitating the juices over their prey after crushing the prey with their jaws.

Reproduction:

Spiders are either male or female. Males use courtship rituals to gain the right to mate with a female. The female often kills and eats the male following mating. Eggs will be laid in a cocoon and hatch in a couple of weeks.

WELL KNOWN SPIDERS:

• ............................... - one of the largest spiders, any of a group of large, hairy spiders. Not dangerous to humans.
• ............................... - best known of the dangerous spiders, can be identified by the red hourglass under its abdomen.
• ............................... - possibly more venomous than the black widow, can be identified by a violin or fiddle shape on its back, its venom produces a wound that enlarges and refuses to heal.

SCORPIONS - Scorpions have greatly enlarged pedipalps that resemble claws. The abdomen has a stinger that is used to kill prey. Several species may be deadly to humans. Local species are not very dangerous.

........................................

Smallest of the arachnids, many are parasitic (some live on your eyelashes where they feed on dead skin and bacteria). Ticks are known to carry two dangerous diseases, ........................................ and .................... disease. Any rash that develops after being bitten by a tick should be evaluated by a doctor.

CLASS - ..................................

Includes the crayfish, lobsters, crabs, shrimp, pill bugs, and sow bugs. They range in size from microscopic water fleas to the giant crab with a length of 12 ft.

The CRAYFISH is the one most commonly studied.

Crayfish Structures:

.................. - external covering over the cephalothorax

Rostrum - pointed structure between the eyes

............................ eyes - contain many lenses

............................ - organs of touch, taste and smell

............................ - organs of hearing and balance

............................ - chewing jaws

............................ - "little jaws"; help chew

............................ - "jaw feet" help hold food

............................ - "claw feet" used for feeding and protection

............................ - 8 (four pairs)

............................ - abdominal appendages that assist in swimming; carry eggs until hatched

.......................... - flipper

............................ - feathery structures under the carapace

................. Circulatory System - blood collects in pools called sinuses

................ - pores in the heart that allow blood to re-enter

Crayfish mate in the fall and lay eggs in the spring. Eggs are carried by the female on her swimmarets until hatching (approx. 6-8 weeks)

Crayfish molt their exoskeleton many times during their lifespan of 3-4 years.

CLASS - CHILOPODA (.................)

..................... pair of legs per segment, Actual number of legs may vary from 15 pairs to 177 pairs. Centipedes have poison claws on the first segment and are carnivorous.

CLASS - DIPLOPODA (.........................)

................ pairs of legs per segment, maximum number of legs recorded is 710. Millipedes are non-poisonous and feed on plants. They may curl up if disturbed.

CLASS - INSECTA

................................. - the study of insects

Almost ...............% of all animals are insects. They are found in every type of environment except salt water. Many are beneficial: pollinating flowers and crops, produce honey, silk, shellac, kill harmful insects, act as scavengers. Only ..............% are harmful but they may: destroy food, injure trees, carry diseases, destroy wood, bite, and sting.

CHARACTERISTICS:

3 Body Sections (................, ..................., .......................),

Antennae, ............. legs, Compound eyes

Mouthparts that may be modified for: Chewing, Sucking, or Lapping

CLASSIFICATION

Some of the major Insect orders are:

ORTHOPTERA - ..................................

ISOPTERA - Termites

HEMIPTERA - True bugs, squash bugs

HOMOPTERA - Cicadas, aphids

.............................. - Flies, mosquitos

LEPIDOPTERA - .................................

COLEOPTERA - Beetles

.............................. - Ants, bees, wasps

GRASSHOPPER STRUCTURES

................................... - upper lip

.................................... - lower lip

.................................... - 2

.................................... - 3

.............THORAX - first section of thorax

.............THORAX - 2nd section; forewings attached

.............THORAX - 3rd section; hindwings attached

WALKING LEGS - 1st two pairs

JUMPING LEGS - 3rd pair

COXA - attaches leg to thorax

TROCHANTER - attaches coxa to femur

FEMUR - largest part of leg; muscular

TIBIA - lower leg

TARSUS - grasping foot

........................ - eardrums

SPIRACLES - external openings to tracheae

TRACHEAE - breathing tubes

....................... - stores food

SALIVARY GLANDS - moistens food in crop

...................... - grinds food

MIDGUT - stomach

............................... CAECAE - secrete enzymes

HINDGUT - intestine

.................. CIRCULATORY SYSTEM

AORTA - major blood vessel leaving heart

OSTIA - pores in the heart

MALPIGHIAN TUBULES - remove nitrogen wastes from blood; eliminated as dry uric acid crystals to save water

VENTRAL NERVE CORDS - two

................... - nerve masses in each segment that allow a grasshopper to function even after the head is cut off

.......................... - pointed organs females use to lay eggs

INSECT DEVELOPMENT - ................................. - change in form

COMPLETE METAMORPHOSIS

1. .........................

2. ......................... - immature form such as maggots, caterpillars, etc.

3. ........................ - cocoon stage

4. .........................

INCOMPLETE METAMORPHOSIS

1. Egg

2. ...............- resembles adult except for size, lack of wings, and inability to reproduce

3. Adult

INSECT BEHAVIOR

...................... INSECTS (............., ............., .................)

Social insects live in communities and engage in DIVISION OF ..........

BEES:

..................... - largest member of hive; raised on special diet of "royal jelly." Her only job is to lay eggs. She leaves the hive only once, to mate with drones, and receives enough sperm to lay eggs for her 5-7 years.

................... - male bees; develop from unfertilized eggs. Their only job is to mate with the queen. When food gets low the workers will drive them away or sting them to death.

................... - female bees; develop from fertilized eggs fed a regular diet. During first week of adult life she feeds queen, drones, and larvae. Next, she makes wax to build, repair and clean the hive. Finally she searches for food (nectar). The nectar is stored in her crop, then regurgitated into the cells of the honeycomb. The action of enzymes from her digestive system and evaporation change it into HONEY. The worker is the only one with a stinger.

Lifespan = 6 weeks.

COMMUNICATION

Insects communicate through chemicals, visual signals, sounds, and motions.

............................. - chemicals that influence the behavior of other insects (Signals readiness to mate). Fireflies signal mates by flashing a light. Others have courtship rituals that include tapping, rubbing, or stroking.

Dance of the Honeybee

Bees that locate a supply of nectar can describe where it is by doing a "................................" The number of circles, direction from the sun, and number of wiggles communicates direction and distance to the food.

DEFENSE:

Most bugs will flee when threatened, others may:

1. secrete foul-smelling substances

2. ........................... or ....................

3. contain ...............................

4. resemble stinging or bad-tasting insects (this is called ...................)

5. .......................... themselves

CONTROL OF INSECTS

1. ......................... - isolation of insects, plants, or people

2. ................... ......................... - Insecticides

3. ...................... control - drain swamps, rotate crops

4. ...................... control - use natural enemies

5. ...................... control - release sterile males to compete for females. Resulting eggs won't hatch