Ontario Mosquito and Biting Flies
Category Practice Exam Questions,
Answers & rationales | latest update
Q1
Biology & Life Cycle
Which of the following correctly describes the life cycle of mosquitoes?
A) Egg, nymph, adult
✓ B) Egg, larva, pupa, adult (correct answer)
C) Egg, larva, adult
D) Larva, pupa, adult
Rationale: Mosquitoes undergo complete metamorphosis
(holometabolism) with four distinct stages: egg, larva (wriggler), pupa
(tumbler), and adult. This is a key distinguishing feature from
hemimetabolous insects like blackflies at the larval stage.
Q2
Biology & Life Cycle
How long does it typically take for a mosquito egg to hatch under optimal
conditions in Ontario?
A) 1–2 days
B) 1–2 weeks
C) 3–4 weeks
✓ D) 24–48 hours (correct answer)
Rationale: Mosquito eggs typically hatch within 24–48 hours under warm,
optimal conditions. Temperature significantly accelerates or delays
hatching, and in Ontario's cooler climate development may take longer.
Q3
Biology & Life Cycle
Which mosquito life stage is entirely aquatic?
A) Adult only
B) Pupa and adult
✓ C) Egg, larva, and pupa (correct answer)
,D) Larva only
Rationale: The egg, larva, and pupa stages are all aquatic. Only the adult is
terrestrial. This is critical knowledge for control strategies, as water source
elimination targets three of the four life stages.
Q4
Biology & Life Cycle
Mosquito larvae breathe primarily through:
A) Gills on their abdomen
✓ B) A siphon tube at the end of the abdomen (correct answer)
C) Spiracles along the thorax
D) Diffusion through the cuticle
Rationale: Most mosquito larvae (family Culicidae) breathe through a
siphon tube located at the end of the abdomen, which they use to access
atmospheric oxygen at the water surface. This is why larvae must come to
the surface to breathe.
Q5
Biology & Life Cycle
What is the feeding behaviour of female mosquitoes?
A) They feed only on plant nectar
✓ B) They require a blood meal for egg production (correct answer)
C) Both males and females require blood meals
D) They feed on decaying organic matter
Rationale: Only female mosquitoes take blood meals, which provide the
protein necessary for egg development (vitellogenesis). Both males and
females feed on plant nectar and sugars for energy.
Q6
Biology & Life Cycle
The 'wriggler' stage of a mosquito refers to:
A) The egg
✓ B) The larva (correct answer)
C) The pupa
D) The newly emerged adult
Rationale: 'Wriggler' is a common name for the mosquito larva because of
its characteristic wriggling movement in water. Similarly, the pupa is called
a 'tumbler' due to its tumbling motion.
,Q7
Biology & Life Cycle
How many larval instars do mosquitoes typically pass through?
A) Two
B) Three
✓ C) Four (correct answer)
D) Five
Rationale: Mosquitoes typically pass through four larval instars, each
separated by a moult (ecdysis). The fourth instar larva then moults into the
pupal stage.
Q8
Biology & Life Cycle
The pupal stage of a mosquito is unique because:
A) It is the only feeding stage
✓ B) It does not feed but is still mobile (correct answer)
C) It is completely immobile
D) It requires a blood meal
Rationale: The mosquito pupa is non-feeding but mobile — it can swim
actively using paddle-like appendages (swimming paddles). This
distinguishes it from many other holometabolous insects where the pupal
stage is immobile.
Q9
Biology & Life Cycle
Which condition is most essential for mosquito egg hatching?
A) High temperatures above 35°C
✓ B) Presence of water and a triggering stimulus (correct answer)
C) Absence of sunlight
D) High salinity water
Rationale: Mosquito egg hatching requires contact with water and
appropriate stimuli such as low dissolved oxygen, temperature change, or
microbial activity. Floodwater mosquito eggs are desiccation-resistant and
can persist for years until flooding occurs.
Q10
Biology & Life Cycle
, At what water temperature does mosquito larval development become
negligible?
✓ A) Below 10°C (correct answer)
B) Below 20°C
C) Below 5°C
D) Below 15°C
Rationale: Mosquito larval development slows dramatically below 10°C and
essentially stops. This is why mosquito activity is seasonal in Ontario,
ceasing in late autumn and winter.
Q11
Identification
Which of the following best describes the wing venation of adult
mosquitoes?
✓ A) Wings are covered with flat scales (correct answer)
B) Wings have a network of veins with no scales
C) Wings are hairy (pilose) along the margins
D) Wings are absent in females
Rationale: Mosquito wings are covered with flat scales, a key identifying
characteristic of the family Culicidae. This distinguishes them from
blackflies and midges, which do not have scaled wings.
Q12
Identification
What is the key identification feature that distinguishes mosquitoes from
other biting flies?
A) Three pairs of legs
✓ B) Long proboscis projecting forward (correct answer)
C) Large compound eyes
D) Presence of halteres
Rationale: The elongated, forward-projecting proboscis is the most
distinctive feature of mosquitoes, used for piercing host skin and feeding.
While other Diptera have halteres, the scaled wings and long mouthparts
are unique to Culicidae.
Q13
Identification
Category Practice Exam Questions,
Answers & rationales | latest update
Q1
Biology & Life Cycle
Which of the following correctly describes the life cycle of mosquitoes?
A) Egg, nymph, adult
✓ B) Egg, larva, pupa, adult (correct answer)
C) Egg, larva, adult
D) Larva, pupa, adult
Rationale: Mosquitoes undergo complete metamorphosis
(holometabolism) with four distinct stages: egg, larva (wriggler), pupa
(tumbler), and adult. This is a key distinguishing feature from
hemimetabolous insects like blackflies at the larval stage.
Q2
Biology & Life Cycle
How long does it typically take for a mosquito egg to hatch under optimal
conditions in Ontario?
A) 1–2 days
B) 1–2 weeks
C) 3–4 weeks
✓ D) 24–48 hours (correct answer)
Rationale: Mosquito eggs typically hatch within 24–48 hours under warm,
optimal conditions. Temperature significantly accelerates or delays
hatching, and in Ontario's cooler climate development may take longer.
Q3
Biology & Life Cycle
Which mosquito life stage is entirely aquatic?
A) Adult only
B) Pupa and adult
✓ C) Egg, larva, and pupa (correct answer)
,D) Larva only
Rationale: The egg, larva, and pupa stages are all aquatic. Only the adult is
terrestrial. This is critical knowledge for control strategies, as water source
elimination targets three of the four life stages.
Q4
Biology & Life Cycle
Mosquito larvae breathe primarily through:
A) Gills on their abdomen
✓ B) A siphon tube at the end of the abdomen (correct answer)
C) Spiracles along the thorax
D) Diffusion through the cuticle
Rationale: Most mosquito larvae (family Culicidae) breathe through a
siphon tube located at the end of the abdomen, which they use to access
atmospheric oxygen at the water surface. This is why larvae must come to
the surface to breathe.
Q5
Biology & Life Cycle
What is the feeding behaviour of female mosquitoes?
A) They feed only on plant nectar
✓ B) They require a blood meal for egg production (correct answer)
C) Both males and females require blood meals
D) They feed on decaying organic matter
Rationale: Only female mosquitoes take blood meals, which provide the
protein necessary for egg development (vitellogenesis). Both males and
females feed on plant nectar and sugars for energy.
Q6
Biology & Life Cycle
The 'wriggler' stage of a mosquito refers to:
A) The egg
✓ B) The larva (correct answer)
C) The pupa
D) The newly emerged adult
Rationale: 'Wriggler' is a common name for the mosquito larva because of
its characteristic wriggling movement in water. Similarly, the pupa is called
a 'tumbler' due to its tumbling motion.
,Q7
Biology & Life Cycle
How many larval instars do mosquitoes typically pass through?
A) Two
B) Three
✓ C) Four (correct answer)
D) Five
Rationale: Mosquitoes typically pass through four larval instars, each
separated by a moult (ecdysis). The fourth instar larva then moults into the
pupal stage.
Q8
Biology & Life Cycle
The pupal stage of a mosquito is unique because:
A) It is the only feeding stage
✓ B) It does not feed but is still mobile (correct answer)
C) It is completely immobile
D) It requires a blood meal
Rationale: The mosquito pupa is non-feeding but mobile — it can swim
actively using paddle-like appendages (swimming paddles). This
distinguishes it from many other holometabolous insects where the pupal
stage is immobile.
Q9
Biology & Life Cycle
Which condition is most essential for mosquito egg hatching?
A) High temperatures above 35°C
✓ B) Presence of water and a triggering stimulus (correct answer)
C) Absence of sunlight
D) High salinity water
Rationale: Mosquito egg hatching requires contact with water and
appropriate stimuli such as low dissolved oxygen, temperature change, or
microbial activity. Floodwater mosquito eggs are desiccation-resistant and
can persist for years until flooding occurs.
Q10
Biology & Life Cycle
, At what water temperature does mosquito larval development become
negligible?
✓ A) Below 10°C (correct answer)
B) Below 20°C
C) Below 5°C
D) Below 15°C
Rationale: Mosquito larval development slows dramatically below 10°C and
essentially stops. This is why mosquito activity is seasonal in Ontario,
ceasing in late autumn and winter.
Q11
Identification
Which of the following best describes the wing venation of adult
mosquitoes?
✓ A) Wings are covered with flat scales (correct answer)
B) Wings have a network of veins with no scales
C) Wings are hairy (pilose) along the margins
D) Wings are absent in females
Rationale: Mosquito wings are covered with flat scales, a key identifying
characteristic of the family Culicidae. This distinguishes them from
blackflies and midges, which do not have scaled wings.
Q12
Identification
What is the key identification feature that distinguishes mosquitoes from
other biting flies?
A) Three pairs of legs
✓ B) Long proboscis projecting forward (correct answer)
C) Large compound eyes
D) Presence of halteres
Rationale: The elongated, forward-projecting proboscis is the most
distinctive feature of mosquitoes, used for piercing host skin and feeding.
While other Diptera have halteres, the scaled wings and long mouthparts
are unique to Culicidae.
Q13
Identification
