ENT 202 Exam 3 — Introduction to Entomology 2026/2027
ENT 202 EXAM 3 — INTRODUCTION TO ENTOMOLOGY
Comprehensive Entomological Competency Assessment
75 Questions | Testing Time: 90–120 Minutes | Passing Score: 75–80%
2026/2027 Academic Year
Instructions: This examination consists of 75 multiple-choice questions distributed across ten domains of
entomological knowledge. Each question has four response options (A–D); select the single best answer.
Questions range from straightforward recall of taxonomic and morphological facts to applied scenarios
requiring integration of IPM principles, vector ecology, forensic methodology, and ecological theory. Some
questions present case-based vignettes testing clinical, agricultural, or forensic decision-making. You may
not use electronic devices, textbooks, or reference materials unless explicitly permitted by the proctor.
Manage your time carefully, allocating approximately 1.5 minutes per question. Record all answers on the
provided answer sheet. Review your responses if time permits.
Domain 1: Insect Taxonomy & Systematics
1. Which insect order is characterized by having two pairs of wings covered in microscopic
scales, a coiled siphoning mouthpart, and complete (holometabolous) metamorphosis?
A. Coleoptera
B. Lepidoptera
C. Diptera
D. Hymenoptera
Correct Answer: B
Rationale: Lepidoptera (butterflies and moths) are uniquely defined by wings covered in overlapping
scales derived from modified setae, a proboscis formed from elongated galeae that coils when not in use,
and holometabolous development. Coleoptera have hardened forewings (elytra), Diptera have only one
pair of functional wings with halteres, and Hymenoptera possess hamuli for wing coupling.
2. Members of the order Diptera can be distinguished from all other insect orders by which
diagnostic character?
A. Possession of piercing-sucking mouthparts
B. Reduction of the hind wings to halteres
C. Presence of a frons and clypeus suture
D. Holometabolous development with eruciform larvae
Correct Answer: B
Rationale: The defining synapomorphy of Diptera is the modification of the metathoracic wings into
halteres, which serve as gyroscopic balance organs during flight. While many flies have sponging or
piercing-sucking mouthparts, these are not universal across the order. Holometabolous development is
shared with several other orders, and a frons-clypeus suture is present in many insects.
3. In cladistic analysis, a synapomorphy is best defined as:
A. A derived character state shared by two or more taxa and their most recent common ancestor
B. A primitive character state inherited from a distant ancestor
C. A character that has evolved independently in unrelated lineages due to convergent evolution
D. A character that is variable within a single species
Correct Answer: A
Rationale: A synapomorphy is a shared derived character state that provides evidence for monophyletic
groupings. It is the cornerstone of cladistic methodology because it identifies clades based on shared
evolutionary innovations. Option B describes a symplesiomorphy, Option C describes homoplasy, and
Option D describes intraspecific polymorphism, none of which are used to define clades.
4. Which order of insects possesses elongated cerci modified into forceps-like structures and
exhibits hemimetabolous development?
A. Orthoptera
B. Dermaptera
C. Blattodea
1
, ENT 202 Exam 3 — Introduction to Entomology 2026/2027
D. Plecoptera
Correct Answer: B
Rationale: Dermaptera (earwigs) are readily identified by their distinctive forceps-like cerci, which are
used in defense, prey capture, and wing folding. They undergo incomplete (hemimetabolous)
metamorphosis. Orthoptera have jumping hind legs and shorter cerci, Blattodea (cockroaches and
termites) have long antennae and cerci but not forceps-like, and Plecoptera (stoneflies) have long cerci that
are not forceps-like and are associated with aquatic nymphs.
5. The scientific name of an organism consists of a genus and species designation. According
to the International Code of Zoological Nomenclature (ICZN), which of the following is a
correctly formatted binomen?
A. Vanessa atalanta
B. Vanessa Atalanta
C. vanessa atalanta
D. Vanessa atalanta L.
Correct Answer: A
Rationale: Under the ICZN, a valid binomen requires the genus name capitalized, the specific epithet in
lowercase, and both italicized (or underlined in handwritten form). Option B incorrectly capitalizes the
specific epithet. Option C does not capitalize the genus. Option D includes an author abbreviation, which,
while sometimes appended, is not part of the binomen itself and should not be the sole basis for identifying
correct formatting of the binomial name.
6. Hymenoptera can be divided into two major subgroups based on the constriction between
the first and second abdominal segments. What is this constriction called, and which
subgroup possesses it?
A. Petiole; Apocrita possess it
B. Propodeum; Symphyta possess it
C. Tergum; Apocrita possess it
D. Node; Symphyta possess it
Correct Answer: A
Rationale: The petiole is the narrow constriction between the first and second abdominal segments that
characterizes the suborder Apocrita (ants, bees, wasps), giving them a distinctive wasp-waisted
appearance. The Symphyta (sawflies and wood wasps) lack this constriction and have a broadly attached
thorax and abdomen. The propodeum is actually the first abdominal segment fused to the thorax in
Apocrita, not the constriction itself.
7. Which principle states that the preferred cladistic hypothesis is the one requiring the
fewest evolutionary changes?
A. Monophyly principle
B. Maximum likelihood
C. Parsimony
D. Bayesian inference
Correct Answer: C
Rationale: The principle of parsimony (also known as Occam's Razor applied to phylogenetics) favors the
cladistic tree that explains the observed character states with the fewest number of evolutionary
transitions. While maximum likelihood and Bayesian inference are alternative phylogenetic methods that
incorporate statistical models, parsimony remains a foundational approach in cladistics. The monophyly
principle ensures groups include all descendants of a common ancestor but does not address tree selection.
8. A type specimen that is the single specimen upon which the name of a new species is
formally established is called a:
A. Paratype
B. Syntype
C. Holotype
D. Lectotype
Correct Answer: C
Rationale: The holotype is the single specimen designated by the author as the name-bearing type of a new
species. Paratypes are additional specimens studied by the author but are not the primary name-bearing
2
, ENT 202 Exam 3 — Introduction to Entomology 2026/2027
specimen. Syntypes are a series of specimens collectively serving as the type when no holotype was
designated. A lectotype is a specimen later selected from syntypes to serve as the definitive type specimen.
Domain 2: Insect Morphology & Anatomy
9. Which type of antennae, characterized by short, abruptly angled segments resembling a
bent elbow, is commonly found in ants (Formicidae) and some beetles?
A. Filiform
B. Clavate
C. Geniculate
D. Plumose
Correct Answer: C
Rationale: Geniculate antennae have an elongated first segment (scape) followed by an abrupt angle, with
the remaining segments forming a flexible club. This is the characteristic antenna of ants and is also seen in
some weevils (Curculionidae). Filiform antennae are thread-like without modification, clavate antennae
gradually thicken toward the tip, and plumose antennae are feathery with lateral branches on each
segment.
10. In the insect digestive system, the peritrophic matrix is produced in and lines which
region?
A. Foregut (stomodaeum)
B. Midgut (mesenteron)
C. Hindgut (proctodaeum)
D. Crop
Correct Answer: B
Rationale: The peritrophic matrix (or peritrophic membrane) is a semi-permeable, chitin-protein mesh
secreted by the midgut epithelium. It serves to protect the delicate midgut cells from mechanical damage by
food particles and from pathogen entry, while allowing the passage of digestive enzymes and nutrients.
The foregut is lined with cuticle derived from ectoderm, and the hindgut is also ectodermal in origin,
neither producing the peritrophic matrix.
11. The tracheal system of insects delivers oxygen directly to tissues via which terminal
structures?
A. Spiracles
B. Tracheae
C. Tracheoles
D. Air sacs
Correct Answer: C
Rationale: Tracheoles are the finest branches of the tracheal system, typically less than 1 micrometer in
diameter, that directly contact individual cells and tissues for gas exchange. Spiracles are the external
openings that allow air entry, tracheae are the larger conducting tubes reinforced with taenidia, and air
sacs are dilated, collapsible regions that facilitate ventilation but do not directly deliver oxygen to tissues.
12. Which wing coupling mechanism, involving a bristle-like structure on the hind wing that
engages with a retinaculum on the forewing, is characteristic of most Lepidoptera?
A. Hamuli
B. Frenulum-retinaculum
C. Amplexiform
D. Jugal lobe
Correct Answer: B
Rationale: The frenulum-retinaculum coupling mechanism consists of a stiff bristle (frenulum) on the hind
wing base that hooks into a membranous fold or set of bristles (retinaculum) on the forewing underside.
This is found in most moths and some butterflies. Hamuli are tiny hooks along the anterior margin of the
hind wing in Hymenoptera. Amplexiform coupling involves an overlapping humeral area of the hind wing
with the forewing. The jugal lobe is a posterior basal lobe used in some primitive coupling.
13. Raptorial forelegs, modified for grasping prey with spines and a folding mechanism, are a
hallmark of which insect order?
A. Mantodea
3
ENT 202 EXAM 3 — INTRODUCTION TO ENTOMOLOGY
Comprehensive Entomological Competency Assessment
75 Questions | Testing Time: 90–120 Minutes | Passing Score: 75–80%
2026/2027 Academic Year
Instructions: This examination consists of 75 multiple-choice questions distributed across ten domains of
entomological knowledge. Each question has four response options (A–D); select the single best answer.
Questions range from straightforward recall of taxonomic and morphological facts to applied scenarios
requiring integration of IPM principles, vector ecology, forensic methodology, and ecological theory. Some
questions present case-based vignettes testing clinical, agricultural, or forensic decision-making. You may
not use electronic devices, textbooks, or reference materials unless explicitly permitted by the proctor.
Manage your time carefully, allocating approximately 1.5 minutes per question. Record all answers on the
provided answer sheet. Review your responses if time permits.
Domain 1: Insect Taxonomy & Systematics
1. Which insect order is characterized by having two pairs of wings covered in microscopic
scales, a coiled siphoning mouthpart, and complete (holometabolous) metamorphosis?
A. Coleoptera
B. Lepidoptera
C. Diptera
D. Hymenoptera
Correct Answer: B
Rationale: Lepidoptera (butterflies and moths) are uniquely defined by wings covered in overlapping
scales derived from modified setae, a proboscis formed from elongated galeae that coils when not in use,
and holometabolous development. Coleoptera have hardened forewings (elytra), Diptera have only one
pair of functional wings with halteres, and Hymenoptera possess hamuli for wing coupling.
2. Members of the order Diptera can be distinguished from all other insect orders by which
diagnostic character?
A. Possession of piercing-sucking mouthparts
B. Reduction of the hind wings to halteres
C. Presence of a frons and clypeus suture
D. Holometabolous development with eruciform larvae
Correct Answer: B
Rationale: The defining synapomorphy of Diptera is the modification of the metathoracic wings into
halteres, which serve as gyroscopic balance organs during flight. While many flies have sponging or
piercing-sucking mouthparts, these are not universal across the order. Holometabolous development is
shared with several other orders, and a frons-clypeus suture is present in many insects.
3. In cladistic analysis, a synapomorphy is best defined as:
A. A derived character state shared by two or more taxa and their most recent common ancestor
B. A primitive character state inherited from a distant ancestor
C. A character that has evolved independently in unrelated lineages due to convergent evolution
D. A character that is variable within a single species
Correct Answer: A
Rationale: A synapomorphy is a shared derived character state that provides evidence for monophyletic
groupings. It is the cornerstone of cladistic methodology because it identifies clades based on shared
evolutionary innovations. Option B describes a symplesiomorphy, Option C describes homoplasy, and
Option D describes intraspecific polymorphism, none of which are used to define clades.
4. Which order of insects possesses elongated cerci modified into forceps-like structures and
exhibits hemimetabolous development?
A. Orthoptera
B. Dermaptera
C. Blattodea
1
, ENT 202 Exam 3 — Introduction to Entomology 2026/2027
D. Plecoptera
Correct Answer: B
Rationale: Dermaptera (earwigs) are readily identified by their distinctive forceps-like cerci, which are
used in defense, prey capture, and wing folding. They undergo incomplete (hemimetabolous)
metamorphosis. Orthoptera have jumping hind legs and shorter cerci, Blattodea (cockroaches and
termites) have long antennae and cerci but not forceps-like, and Plecoptera (stoneflies) have long cerci that
are not forceps-like and are associated with aquatic nymphs.
5. The scientific name of an organism consists of a genus and species designation. According
to the International Code of Zoological Nomenclature (ICZN), which of the following is a
correctly formatted binomen?
A. Vanessa atalanta
B. Vanessa Atalanta
C. vanessa atalanta
D. Vanessa atalanta L.
Correct Answer: A
Rationale: Under the ICZN, a valid binomen requires the genus name capitalized, the specific epithet in
lowercase, and both italicized (or underlined in handwritten form). Option B incorrectly capitalizes the
specific epithet. Option C does not capitalize the genus. Option D includes an author abbreviation, which,
while sometimes appended, is not part of the binomen itself and should not be the sole basis for identifying
correct formatting of the binomial name.
6. Hymenoptera can be divided into two major subgroups based on the constriction between
the first and second abdominal segments. What is this constriction called, and which
subgroup possesses it?
A. Petiole; Apocrita possess it
B. Propodeum; Symphyta possess it
C. Tergum; Apocrita possess it
D. Node; Symphyta possess it
Correct Answer: A
Rationale: The petiole is the narrow constriction between the first and second abdominal segments that
characterizes the suborder Apocrita (ants, bees, wasps), giving them a distinctive wasp-waisted
appearance. The Symphyta (sawflies and wood wasps) lack this constriction and have a broadly attached
thorax and abdomen. The propodeum is actually the first abdominal segment fused to the thorax in
Apocrita, not the constriction itself.
7. Which principle states that the preferred cladistic hypothesis is the one requiring the
fewest evolutionary changes?
A. Monophyly principle
B. Maximum likelihood
C. Parsimony
D. Bayesian inference
Correct Answer: C
Rationale: The principle of parsimony (also known as Occam's Razor applied to phylogenetics) favors the
cladistic tree that explains the observed character states with the fewest number of evolutionary
transitions. While maximum likelihood and Bayesian inference are alternative phylogenetic methods that
incorporate statistical models, parsimony remains a foundational approach in cladistics. The monophyly
principle ensures groups include all descendants of a common ancestor but does not address tree selection.
8. A type specimen that is the single specimen upon which the name of a new species is
formally established is called a:
A. Paratype
B. Syntype
C. Holotype
D. Lectotype
Correct Answer: C
Rationale: The holotype is the single specimen designated by the author as the name-bearing type of a new
species. Paratypes are additional specimens studied by the author but are not the primary name-bearing
2
, ENT 202 Exam 3 — Introduction to Entomology 2026/2027
specimen. Syntypes are a series of specimens collectively serving as the type when no holotype was
designated. A lectotype is a specimen later selected from syntypes to serve as the definitive type specimen.
Domain 2: Insect Morphology & Anatomy
9. Which type of antennae, characterized by short, abruptly angled segments resembling a
bent elbow, is commonly found in ants (Formicidae) and some beetles?
A. Filiform
B. Clavate
C. Geniculate
D. Plumose
Correct Answer: C
Rationale: Geniculate antennae have an elongated first segment (scape) followed by an abrupt angle, with
the remaining segments forming a flexible club. This is the characteristic antenna of ants and is also seen in
some weevils (Curculionidae). Filiform antennae are thread-like without modification, clavate antennae
gradually thicken toward the tip, and plumose antennae are feathery with lateral branches on each
segment.
10. In the insect digestive system, the peritrophic matrix is produced in and lines which
region?
A. Foregut (stomodaeum)
B. Midgut (mesenteron)
C. Hindgut (proctodaeum)
D. Crop
Correct Answer: B
Rationale: The peritrophic matrix (or peritrophic membrane) is a semi-permeable, chitin-protein mesh
secreted by the midgut epithelium. It serves to protect the delicate midgut cells from mechanical damage by
food particles and from pathogen entry, while allowing the passage of digestive enzymes and nutrients.
The foregut is lined with cuticle derived from ectoderm, and the hindgut is also ectodermal in origin,
neither producing the peritrophic matrix.
11. The tracheal system of insects delivers oxygen directly to tissues via which terminal
structures?
A. Spiracles
B. Tracheae
C. Tracheoles
D. Air sacs
Correct Answer: C
Rationale: Tracheoles are the finest branches of the tracheal system, typically less than 1 micrometer in
diameter, that directly contact individual cells and tissues for gas exchange. Spiracles are the external
openings that allow air entry, tracheae are the larger conducting tubes reinforced with taenidia, and air
sacs are dilated, collapsible regions that facilitate ventilation but do not directly deliver oxygen to tissues.
12. Which wing coupling mechanism, involving a bristle-like structure on the hind wing that
engages with a retinaculum on the forewing, is characteristic of most Lepidoptera?
A. Hamuli
B. Frenulum-retinaculum
C. Amplexiform
D. Jugal lobe
Correct Answer: B
Rationale: The frenulum-retinaculum coupling mechanism consists of a stiff bristle (frenulum) on the hind
wing base that hooks into a membranous fold or set of bristles (retinaculum) on the forewing underside.
This is found in most moths and some butterflies. Hamuli are tiny hooks along the anterior margin of the
hind wing in Hymenoptera. Amplexiform coupling involves an overlapping humeral area of the hind wing
with the forewing. The jugal lobe is a posterior basal lobe used in some primitive coupling.
13. Raptorial forelegs, modified for grasping prey with spines and a folding mechanism, are a
hallmark of which insect order?
A. Mantodea
3
