Metamorphosis Flashcards
What are the three different types of insect development?
- holometabolous - complete
- hemimetabolous - gradual or incomplete
- ametabolous - juvenile -> juvenile
Discuss holometabolous metamorphosis.
- Most common (80 - 90% species)
- flies
- beetles
- Lepidoptera
- Four stages:
1. eggs
2. larvae
3. pupa - looks nothing like adult, exposed or in cocoon, nonfeeding / immobile
4. adult
Discuss hemimetabolous metamorphosis.
(aka paurometabolous)
Can be gradual or incomplete:
- Gradual
1. egg
2. nymph - looks like adults but no wings / reproductive organs
3. adult - Incomplete
Naiads are immatures.
Discuss ametabolous metamorphosis.
No metamorphosis… juvenile to adult is a gradual change.
Indefinite molts (adults still molt); females must mate after each molt.
This occurs in silverfish and non-insect arthropods.
How many stages are in holometabolous metamorphosis?
What are they?
Four stages in complete metamorphosis:
- Egg
- Larvae
- Pupa
- Adult
What groups of insects use holometabolous metamorphosis?
80 - 90% species are holometabolous:
- flies
- beetles
- Lepidoptera
- Hymenoptera
Hemimetabolous is also known as:
Paurometabolous
Gradual vs. incomplete
Different orders, adults and juveniles live separately
How many stages are in gradual metamorposis?
What are they?
Three stages in gradual metamorphosis:
- Egg
- Nymph (immature)
- Adult
What groups of insects use gradual metamorphosis?
Orthoptera, Hemiptera
How many stages are in incomplete metamorphosis?
What are they?
Three stages in incomplete metamorphosis:
- Eggs
- Naiads - develop near water
- Adults - flying adults
Juveniles and adults have different living spaces.
Give an example of an insect that uses incomplete metamorphosis.
Odonata - dragonflies
What are imaginal disks?
How are they different from wing pads?
Small pockets of undifferentiated tissue inside larvae that become wings.
Wingpads are precursors to wings, found 1 - 2 steps before adulthood.
