2. (Phylum Arthropoda; Sub-Phylum Uniramia)
Insects
(Phylum Arthropoda; Sub-Phylum Uniramia)
Evolved over 300 million years ago
Most successful group of animals (700,000 to 10 million species)

3. Diversity (species and variety)
Numbers (population size)
Success due in part to enormous range of variation
Structural (morphological)
Physiological (chemical)
Behavioral

4. Characteristics and Classification
Body - 3 parts
Head with 1 pair of antennae
Thorax with 3 pair of jointed legs and in many species 1-2 pair of wings
Abdomen with 11 segments (lacks wings and legs)

7. Success of the Found virtually everywhere except the deep ocean
Extremely short life span -> rapid adaptation to new environments
Small size -> greater partitioning of habitats while minimizing competition
Flight -> greater dispersal, escape from predation, and movement into environments less accessible to other species

8. Insects and Human Society
Positive impact
Major pollinator of flowering plants (2/3 of all plants)
Food for fish, birds and mammals (important link in food web)
Help recycle materials (termites)
Useful biproducts (honey and silk)

9. Negative impact
Agricultural pests
Spread disease

10. Grasshoppers 3 main body segments Head (brain and sense organs)
Antennae
Compound and simple eyes
Complex moth parts

11. Thorax (legs and wings attached)
Prothorax and mesothorax (each have pair of walking legs)
Metathorax (jumping legs

12. Abdomen (organs of reproduction, digestion, respiration, and excretion)
2 pair of wings
Leathery protective forewing (mesothorax)
Hind wing which is used for flight (metathorax)

13. Digestive System
Specialized mouthparts (liplike labium and labrum, jawlike mandibles and maxillae)
Salivary glands (produce saliva)
Digestive ceca (produces digestive enzymes)

14. Food -> mouth -> esophagus -> crop (storage) -> gizzard (chitinous plates shred it) -> stomach (mid gut) (mixes with gastric enzymes from ceca and absorbed) -> hind gut (colon and rectum) -> anus

15. Excretory System
Malpighian tubules in hindgut remove wastes from blood and deposit them in the rectum

16. Circulatory System Open circulatory system
Blood -> aorta -> hearts (muscular region of aorta in posterior abdomen) -> anterior coelom (head) -> abdomen (absorbs and disperses nutrients) -> aorta via ostia

17. Respiratory System
Air -> spiracles (opening in thorax and abdomen) -> tracheae (network of air tubes) -> body tissues
Contraction of abdomen reverses process

18. Nervous System Simple brain Ventral nerve cord
3 simple eyes (detect light)
2 compound eyes (composed of hexagonal lenses capable of detecting movement but not sharp images)

19. Tympanum (detects sounds; located on first abdominal segment)
Antennae (detects touch and smell)

20. Reproductive System
Sperm deposited into female's seminal receptacle (stored until eggs are released)
Eggs fertilized internally
Ovipositor (pair of pointed organs at tip of abdomen) used to dig a hole in soil and deposit eggs

21. Development
Metamorphosis - developmental changes -> distinct changes in form and size
Incomplete Metamorphosis
3 stages (egg, nymph, and adult)
Nymph- smaller immature form; similar to adult but underdeveloped reproductive organs and lack wings
Examples are grasshoppers and termites

22. Complete Metamorphosis
4 stages (egg, larva, pupa, and adult)
Examples are butterflies, beetles and most other insects

23. Hormonal Control Controlled by sequential expression of genes
Interaction of 3 hormones (brain, molting and juvenile)

24. Brain hormone stimulates release of molting hormone (effect depends on level of juvenile hormone)
Juvenile hormone level high -> molting hormone -> larva molts
Juvenile hormone level decreases -> molting hormone -> larva develop into pupa
Juvenile hormone absent -> molting hormone -> pupa develops into adult

25. Importance of Metamorphism
Different developmental stages -> different functions (specializations)
Eliminates energy conflicts between growth and reproduction
Eliminates competition between life stages
Multistage life cycle helps survive harsh weather

26. Defense
Defensive adaptations (agressive and passive) -> enhanced survival
Camouflage (cryptic coloration)
Warning coloration
Mullerian mimicry- poisonous or dangerous species having similar patterns of coloration

27. Batesian mimicry- nonpoisonous or nondangerous species having similar pattern or color to a poisonous or dangerous unrelated species

28. Insect Behavior Social behavior in honeybees
Behaviors are genetically determined (instinctual or innate)
Division of labor ->complex societies -> interdependence and need for communication

29. Hive consists of 3 distinct forms
Workers - sterile females; majority of individuals in hive
Queen - fertile female; only function is reproduction
Drones - male bees; only function is

30. Workers Average life span approximately 6 weeks
Perform many functions at different times during their lives
1st stage - feed honey and pollen to queen, drones and larvae (nurse bees); secrete royal jelly (high protein diet)
2nd stage - Stop producing royal jelly and begin secreting wax -> build and repair hive, guard hive and fan wings to circulate fresh air in hive

31. 3rd stage - gather nector and pollen; legs modified with special structures to collect pollen; ovipositor modified for defense (stinger)

32. Queen and Drones
Queen identical to workers except continuously supplied with royal jelly; Queen secretes "queen factor" which prevents other female larvae from becoming sexually mature
Mates only once; sperm stored in seminal receptacle for up to 5 years or more

33. Drones (haploid (n) males) develop from unfertilized eggs; sole function to deliver sperm to queen; must be feed by workers

34. Communication
Pheromones - chemicals released by an animal that affects the behavior or development of other animals of the same species
Sounds
Tapping, rubbing, or signaling

35. Honey Bee communication
Round dance - food source near but no indication of exact location
Waggle dance- food far from hive, dirction of food indicated by the angle of the straight run and the distance indicated by the duration and the number of waggles