LYFE CYCLES IN ANIMALS
INSECT METAMORPHOSIS
METAMORPHOSIS
• Physical changes from one stage in life cycle
to another.
• TWO TYPES OF METAMORPHOSIS:
• 1. Complete metamorphosis
• 2. Incomplete metamorphosis
Comparison of metamorphosis
88 % of all insects
• COMPLETE
• Four stages:
• 1. egg
• 2. larva
• 3. pupa
• 4. adult
• E.g. Butterflies, bees,
housefly
12 % of insects
•
•
•
•
•
INCOMPLETE
Three stages:
1. egg
2. nymph
3. adult
• E.g. Locust, cricket, cockroach
Complete metamorphosis
Incomplete metamorphosis
Advantages and disadvantages of
complete metamorphosis
• Advantages:
1. Larva and adult occupy
different habitats and
niches – not in
competition.
2. Carrying capacity of
ecosystem increased.
3. Egg and pupa stages allow
insect to survive
unfavourable conditions.
• Disadvantages:
1. Larval forms vulnerable to
predators.
2. Suitable habitat for laying
of eggs needed.
3. Change from pupa to
adult requires high
energy-input.
Advantages and disadvantages of
incomplete metamorphosis
• Advantages:
1. Vulnerable pupa stage
avoided.
2. Less energy is needed –
no drastic changes from
pupa to adult.
3. All stages can eat same
food.
• Disadvantages:
1. Nymph and adult often
compete for same food.
2. Insect vulnerable to
dehydration and predators
when moulting.
3. Entire insect population
could be threatened by
environmental changes.
Amphibian metamorphosis