Insect Growth and Development

Question 1

What is Ecdysis?

Answer 1

Molting

The shedding of the old cuticle.

Ecdysis

Question 2

Whats the purpose of molting fluid?

Answer 2

It digests the old cuticle.

Cuticle is the outerlayer of the “skin”

Question 3

Whats the old “skin” / cuticle after molting called?

Answer 3

Exuvium

Question 4

The chemical process of darkening & Hardening of the cuticle?

Answer 4

Sclerotization

A.K.A Tanning

Question 5

What controls the different stages of ecdysis?

Think two chemicals:

Answer 5

• JUVENILE HORMONE (JH)
• ECDYSTEROIDS (20E)

Question 6

When are Ecdysteroid (20E) levels low?

Answer 6

Right before ecdysis

Question 7

When are juvenile hormones low?

JH levels seem to be dependant on another hormone

Answer 7

When Ecdysteriod (20E) levels are high

Question 8

Is Adult Emergance the same as Ecdysis?

Answer 8

Its similar, but males now have sperm store and females typically have eggs or they are now developing

Question 9

Do female or male insects typically take longer to reproductivly mature?

Answer 9

Females

(Varies by species.)

Question 10

Pro-ovigenic

Answer 10

All eggs are present in the female.

Question 11

Synthovigenic

Answer 11

Eggs develop through adulthood.

Question 12

Life cycle terms:

Offspring from a parent population moving through a life cycle together

Answer 12

Generation

Question 13

Life cycle terms:

An insects development status

**EX: **Egg stage, 3rd instar, adult stage

Answer 13

Its stage

Question 14

Life cycle terms:

Time period inbetween molts / ecdysis

Answer 14

Stadium

Question 15

Life cycle terms:

The actual insect between molts

E.g. 3rd-instar has a stadium of 3 days

Answer 15

Instar

Question 16

Types of Metamorphosis:

Simple/Incomplete (Ametabolous)

Answer 16

– Wings (if any) develop externally during immature stages
– Typically no inactive/dormant stage before last molt
– Immatures often look like adults

Question 17

Types of Metamorphosis

Complete (Holometabolous)

Answer 17

– Wings develop internally during the immature stages
– Has a dormant pupal stage before the last molt
– Immatures do not look like adults

Question 18

Types of Metamorphosis

Hemimetabolous

Answer 18

Having no pupal stage in the transition from larva to adult.

Question 19

Metamorphosis

Histogenesis

Answer 19

Breakdown of body
tissues

Question 20

Metamorphosis

Histolysis

Answer 20

Formation of new
tissues

Question 21

Whats a trait for some long living insects?

Answer 21

Reproductive and social

• Ant queen: 18 years
• Termite queen: 12 years
• Honeybee queen: 2-3 years

Question 22

Whats a trait for some short living insects?

Answer 22

No feeding

– Ephemeroptera (Mayflies)

Question 23

Voltinism

Answer 23

How many generations per year.

Question 24

Voltinism

Univoltine

Answer 24

One generation a year

Ex: Grasshoppers, temperant regions

Question 25

# Voltinism Bivoltine

Answer 25

Two generations a year ## Footnote Ex: Silkworms, northern latitudes

Question 26

# Voltinism Multivoltine

Answer 26

2+ generations a year ## Footnote Ex: Aphids

Question 27

# Voltinism Semi-voltine

Answer 27

It takes more than one year to complete a lifecycle, offspring rotate years. ## Footnote Ex: Wire-worms, june beetles

Question 28

Dormancy in insects is often called:

Answer 28

Diapause

Question 29

# What is this insect going through if experiencing these stimuli? -Reduced metabolism -Temperature, photoperiod, humidity, food quality may be off

Answer 29

Diapause

Question 30

Other names for **diapause**?

Answer 30

Overwintering and dormancy

Question 31

# Diapause The type of diapause an insect undergoes from uncomfortable stimuli

Answer 31

Facultative Diapause / Quiescence

Question 32

The type of diapause thats normal to insect development and occurs at a fixed time

Answer 32

Obligatory Diapause

Question 33

# Thermal Regulation Supercooling

Answer 33

Body fluids don’t freeze ## Footnote Antifreeze proteins, Cryoprotectants

Question 34

# Thermal Regulation Freezing Tolerance

Answer 34

Body fluids freeze ## Footnote Freezing outside of cells

Question 35

# Thermal Regulation What are some behaviors insects may have if theyre hot or cold?

Answer 35

- Bask in sunlight - Huddle together - Find shade - Changes self

Question 36

# Thermal Regulation Physiological and morphological Mechanisms to prevent hot or cold temperature:

Answer 36

- Produce more fatty acids - Change colors - Air sac insulation - Pilosity

Question 37

Poikilothermic

Answer 37

Animals whos body temperature fluctuates with the environment