1. Anatomy, Life Cycles and More
Insects 8.01
Anatomy, Life Cycles and More

2. Insects are unique, small animals with three body regions and three pairs of legs

3. Insect Body
Head
Thorax
Abdomen

4. Mouth Five types of mouth parts Chewing Piercing-sucking
Rasping-sucking
Siphoning
Sponging

5. Mouth- chewing
Tear
Chew
Grind food

6. Piercing-sucking
Punctures plant
Sucks sap

7. Rasping-sucking
Rasps
Break surface
Sucks Sap

8. Siphoning
Coiled tube
Dip into nectar food
Proboscis
Draw up food

9. Sponging Two sponge-like structure Collect liquid food
Move it into the food canal

10. Life Cycle- Complete Four Stages Egg Larva (worms and caterpillars)
Pupa
Adult(flies, beetles, and more)

11. Life Cycle- Incomplete
Three stages
Egg
Nymph- aquatic
Adult
Examples
Damselfly
Mosquito
Dragonfly

12. Egg Most insects lay eggs Some insects have live births
Eggs then become larva

13. Larva Larva is the worm-like baby
Larva can be grubs, maggots, caterpillars
They do have little legs

14. Nymph These are immature stages (just smaller versions of adults)
Part of an incomplete life cycle

15. Adult Man…. You know there are all kinds of cool adults
To be an adult, it has to have six legs, head, thorax, abdomen, and a mouthpart!

16. Pupa These are the ugly teenager stage of a complete life cycle
They can be in a chrysallis or cacoon at this time

17. Insect Control
Insects must be killed when they are actively feeding or moving on the plant
Control depends upon mouth part
Chewing= stomach
Piercing= systemic
Contact poisons can be used on soft body

18. Insecticides- Stomach
A pest will ingest this poison.
This poison is often sprayed on the leaf and works well with chewing insects

19. Insecticides- Contact
This is when you spray or fumigate an area
Think of Raid or using a flea bomb in your house

20. Insecticide- Systemic
Systemic runs through the system of the plant through the xylem and phloem
Applied to the roots and sucked up by the insects (eat sap and die sucker! Get it?)

21. Damage Damage depends on the type of mouthpart Chewing Sucking
Piercing
Siphoning
Sponging

22. Beetles
Chewing: Eats it ALL
Mainly a pest
Complete LC
Stomach Poison

23. Cutworms Chewing- Usually attacks stems May eat other plant parts
Complete LC
Stomach Poison/contact
poison

24. Caterpillars Larva of Moths and Butterflies
Chewing- Eats young leaves and stems
Can Sting
Complete LC
Stomach and Contact Poisons

25. Grasshoppers Chewing- Eat all parts of plants
Incomplete LC- hatches and babies just keeping molting skin to become adult!
Enstar can prevent it from molting- expensive!

26. Incomplete Life Cycles Revisited

27. Aphids AKA Plant Lice Pierces and suck juices
Cause stunted growth, yellow spotted leaves
Poop called honeydew, attracts ants (symbiotic relationship)
Incomplete Life Cycle
Asexual reproducers
Aphids produce 12 babies/day!

28. Mealy Bugs Pierce and suck from underside of leaves Suck in leaf axils
Causes yellow appearance
Sticky secretions
Incomplete LC

29. Scales Piercing Sucking Incomplete LC Pain in the butt!
Sticky Secretions
Wingless- crawls

30. Rasping Sucking- Thrips
Chews and then sucks
Causes plant tissue to become speckled or whitened
Leaf tip withers
Leaf curls and dies
Incomplete LC

31. Piercing Sucking- Whiteflies
Feeds on underside of young leaves
Little flying white specks when plants are shaken
Vector for disease
Incomplete LC

32. Piercing Sucking- Spider Mites
Not a “true” insect
Attacks underside of leaf
Causes leaves to turn gray to grayish
Severe infestations cause webbing
Incomplete LC

33. Nematode A microscopic worm (not a “true” insect) A vector of disease
Causes root knot and other sickness
Don’t worry about life cycle or mouth

34. Complete life cycle
Chewing mouthpart when they are eating their prey (like aphids)
Do not want to control them, want to keep them in your greenhouse or garden.

35. Hornets and Wasps
Some bugs, like this wasp, have two types of mouthparts, both siphoning and chewing
Complete LC
Pest- stings and causes damage to structures
Can use contact or stomach

36. Praying Mantid (Mantis)
Incomplete LC
Beneficial Insect- eats bad guys in garden.
Chewing mouthpart.

37. Honey Bee Complete life cycle Chewing and siphoning mouthpart
Beneficial because it is a pollinator.

38. Lady Bug Complete life cycle Chewing mouthpart
As an adult, as a larva (pictured here) it is a voracious eater of other insects…mmmmm.

39. Braconid (Parasitic) Wasp
Complete life cycle
Chewing and siphoning mouthpart
Beneficial because this is an egg layer. The eggs are laid and it will parasitize (eat off of) what it is laid on. Babies are demons!

40. Leaf Bugs Piercing Sucking Incomplete Life Cycle
Causes plants to look unhealthy
Lose normal color and wilt

41. Japanese Beetles Chewing Pest Complete LC
Stomach and contact poisons work

42. White Grub Chewing- roots Larva of beetle Complete LC
Contact and stomach

43. Tomato Hornworm Complete life cycle: this is the larva of a moth.
Chewing mouthpart when it is a pest.
Can be parasitized by the brachonid wasp.

44. Tent Worm Larva of moth Complete LC Chewing
Frass all over the place! Ugly tent!

45. Squash Bugs
Piercing Sucking
Incomplete LC

46. Piercing Sucking
Incomplete LC

47. Leaf Miner Burrows into the leaf Makes little track marks on the leaf
Chewing Mouthparts
Systemic works best
Complete LC

48. Fungus Gnats Little flying pests in greenhouse when it is too moist
Larvae can damage plants
Mainly a pest to people
Chewing
Complete LC
Reduce watering for control