CA PCA Insect, Mites and Other
Invertebrates Classes, Orders and
Families correctly 2026 answered
PART 1: TAXONOMY & CLASSIFICATION (Levels: Class, Order, Family)
Q1. What are the four main classes of the Phylum Arthropoda relevant to the
PCA exam?
A. Gastropoda, Arachnida, Insecta, Chilopoda
B. Malacostraca, Arachnida, Chilopoda, Diplopoda
C. Malacostraca, Arachnida, Insecta, Symphyla
D. Insecta, Arachnida, Gastropoda, Malacostraca
Correct Answer: C
Rationale: The PCA exam specifically covers Class Malacostraca (sowbugs,
pillbugs, and crawdads), Class Arachnida (spiders and mites), Class
Insecta (insects), and Class Symphyla (symphylans). Class Chilopoda
(centipedes) and Diplopoda (millipedes) are also tested but are distinct from the
main four "heavy hitters" required for identification .
Q2. You find a pest in a field with 8 legs and no antennae. It causes stippling
on leaves. What Class does it belong to?
A. Insecta
B. Arachnida
,C. Malacostraca
D. Chilopoda
Correct Answer: B
Rationale: Class Arachnida includes spiders, mites, and ticks. They are
characterized by having two body regions (cephalothorax and abdomen) and four
pairs of legs (8 legs). Insects have 6 legs and one pair of antennae .
Q3. A pest you are scouting has a hard shell, 7 pairs of legs, and rolls into a
ball when disturbed. What is its Order and Class?
A. Isopoda, Malacostraca
B. Orthoptera, Insecta
C. Acari, Arachnida
D. Symphyla, Symphyla
Correct Answer: A
Rationale: This describes the pillbug. While they are crustaceans, they are
classified under Order Isopoda and Class Malacostraca for pest control purposes.
They are occasional pests in crops like alfalfa and strawberries .
Q4. You have identified a pest as Tetranychus urticae. What higher-level
classifications apply?
A. Class Arachnida, Order Acari, Family Tetranychidae
B. Class Insecta, Order Hemiptera, Family Aphididae
C. Class Malacostraca, Order Isopoda, Family Porcellionidae
D. Class Symphyla, Order Symphyla, Family Scolopendrellidae
Correct Answer: A
Rationale: Tetranychus urticae is the scientific name for the Twospotted Spider
Mite. It falls under Class Arachnida (not insects), Order Acari (mites and ticks),
and Family Tetranychidae (web-spinning mites) .
,Q5. Which scientific naming convention is correct for insect classification?
A. Erythroneura variabilis (Genus and species)
B. Tetranychidae (Order)
C. Hemiptera (Family)
D. Coleoptera (Genus)
Correct Answer: A
Rationale: Scientific names are always italicized or underlined with the Genus
capitalized and the species lowercase (e.g., Euschistus conspersus). The other
options incorrectly match taxonomic ranks: Tetranychidae is a family, Hemiptera
is an order, and Coleoptera is an order .
Q6. You find a soft-bodied insect excreting honeydew on a citrus leaf. It has
cornicles (tailpipes) on its abdomen. What Order and Family is it?
A. Coleoptera, Coccinellidae
B. Hemiptera, Aphididae
C. Hemiptera, Diaspididae
D. Thysanoptera, Thripidae
Correct Answer: B
Rationale: The presence of cornicles (the two tubes on the rear) is the defining
characteristic of Family Aphididae (aphids). They belong to
Order Hemiptera (True Bugs) because they have piercing-sucking mouthparts .
Q7. What Order and Family do "true bugs" like stink bugs and lygus bugs
belong to?
A. Order Coleoptera, Family Carabidae
B. Order Hemiptera, Family Pentatomidae
C. Order Hemiptera, Family Miridae
D. Both B and C
Correct Answer: D
Rationale: Both are in Order Hemiptera (True Bugs). Pentatomidae is the family
, for Stink Bugs. Miridae is the family for Plant Bugs (including Lygus/ Tarnished
Plant Bug). The exam requires you to place specific bugs in their correct families .
Q8. You are scouting a cotton field and find a larva with three pairs of jointed
legs on the thorax and five pairs of fleshy prolegs on the abdomen. What
Order is this insect?
A. Coleoptera
B. Hemiptera
C. Lepidoptera
D. Diptera
Correct Answer: C
Rationale: This describes a caterpillar. Larvae of Order Lepidoptera (butterflies
and moths) always have prolegs (fleshy abdominal legs). Coleoptera larvae (grubs)
do not have prolegs; Diptera larvae (maggots) have no legs .
Q9. Which insect Order undergoes complete metamorphosis
(Holometabolous)?
A. Orthoptera (Grasshoppers)
B. Hemiptera (True Bugs)
C. Thysanoptera (Thrips)
D. Coleoptera (Beetles)
Correct Answer: D
Rationale: Complete metamorphosis is Egg -> Larva -> Pupa -> Adult.
Order Coleoptera (Beetles), Lepidoptera, Diptera, and Hymenoptera undergo
complete metamorphosis. Orthoptera and Hemiptera undergo gradual
metamorphosis .
Q10. A PCA finds a pest that jumps when disturbed, has enlarged hind legs,
and is defoliating lettuce. What Order does it belong to?
A. Orthoptera
B. Coleoptera
Invertebrates Classes, Orders and
Families correctly 2026 answered
PART 1: TAXONOMY & CLASSIFICATION (Levels: Class, Order, Family)
Q1. What are the four main classes of the Phylum Arthropoda relevant to the
PCA exam?
A. Gastropoda, Arachnida, Insecta, Chilopoda
B. Malacostraca, Arachnida, Chilopoda, Diplopoda
C. Malacostraca, Arachnida, Insecta, Symphyla
D. Insecta, Arachnida, Gastropoda, Malacostraca
Correct Answer: C
Rationale: The PCA exam specifically covers Class Malacostraca (sowbugs,
pillbugs, and crawdads), Class Arachnida (spiders and mites), Class
Insecta (insects), and Class Symphyla (symphylans). Class Chilopoda
(centipedes) and Diplopoda (millipedes) are also tested but are distinct from the
main four "heavy hitters" required for identification .
Q2. You find a pest in a field with 8 legs and no antennae. It causes stippling
on leaves. What Class does it belong to?
A. Insecta
B. Arachnida
,C. Malacostraca
D. Chilopoda
Correct Answer: B
Rationale: Class Arachnida includes spiders, mites, and ticks. They are
characterized by having two body regions (cephalothorax and abdomen) and four
pairs of legs (8 legs). Insects have 6 legs and one pair of antennae .
Q3. A pest you are scouting has a hard shell, 7 pairs of legs, and rolls into a
ball when disturbed. What is its Order and Class?
A. Isopoda, Malacostraca
B. Orthoptera, Insecta
C. Acari, Arachnida
D. Symphyla, Symphyla
Correct Answer: A
Rationale: This describes the pillbug. While they are crustaceans, they are
classified under Order Isopoda and Class Malacostraca for pest control purposes.
They are occasional pests in crops like alfalfa and strawberries .
Q4. You have identified a pest as Tetranychus urticae. What higher-level
classifications apply?
A. Class Arachnida, Order Acari, Family Tetranychidae
B. Class Insecta, Order Hemiptera, Family Aphididae
C. Class Malacostraca, Order Isopoda, Family Porcellionidae
D. Class Symphyla, Order Symphyla, Family Scolopendrellidae
Correct Answer: A
Rationale: Tetranychus urticae is the scientific name for the Twospotted Spider
Mite. It falls under Class Arachnida (not insects), Order Acari (mites and ticks),
and Family Tetranychidae (web-spinning mites) .
,Q5. Which scientific naming convention is correct for insect classification?
A. Erythroneura variabilis (Genus and species)
B. Tetranychidae (Order)
C. Hemiptera (Family)
D. Coleoptera (Genus)
Correct Answer: A
Rationale: Scientific names are always italicized or underlined with the Genus
capitalized and the species lowercase (e.g., Euschistus conspersus). The other
options incorrectly match taxonomic ranks: Tetranychidae is a family, Hemiptera
is an order, and Coleoptera is an order .
Q6. You find a soft-bodied insect excreting honeydew on a citrus leaf. It has
cornicles (tailpipes) on its abdomen. What Order and Family is it?
A. Coleoptera, Coccinellidae
B. Hemiptera, Aphididae
C. Hemiptera, Diaspididae
D. Thysanoptera, Thripidae
Correct Answer: B
Rationale: The presence of cornicles (the two tubes on the rear) is the defining
characteristic of Family Aphididae (aphids). They belong to
Order Hemiptera (True Bugs) because they have piercing-sucking mouthparts .
Q7. What Order and Family do "true bugs" like stink bugs and lygus bugs
belong to?
A. Order Coleoptera, Family Carabidae
B. Order Hemiptera, Family Pentatomidae
C. Order Hemiptera, Family Miridae
D. Both B and C
Correct Answer: D
Rationale: Both are in Order Hemiptera (True Bugs). Pentatomidae is the family
, for Stink Bugs. Miridae is the family for Plant Bugs (including Lygus/ Tarnished
Plant Bug). The exam requires you to place specific bugs in their correct families .
Q8. You are scouting a cotton field and find a larva with three pairs of jointed
legs on the thorax and five pairs of fleshy prolegs on the abdomen. What
Order is this insect?
A. Coleoptera
B. Hemiptera
C. Lepidoptera
D. Diptera
Correct Answer: C
Rationale: This describes a caterpillar. Larvae of Order Lepidoptera (butterflies
and moths) always have prolegs (fleshy abdominal legs). Coleoptera larvae (grubs)
do not have prolegs; Diptera larvae (maggots) have no legs .
Q9. Which insect Order undergoes complete metamorphosis
(Holometabolous)?
A. Orthoptera (Grasshoppers)
B. Hemiptera (True Bugs)
C. Thysanoptera (Thrips)
D. Coleoptera (Beetles)
Correct Answer: D
Rationale: Complete metamorphosis is Egg -> Larva -> Pupa -> Adult.
Order Coleoptera (Beetles), Lepidoptera, Diptera, and Hymenoptera undergo
complete metamorphosis. Orthoptera and Hemiptera undergo gradual
metamorphosis .
Q10. A PCA finds a pest that jumps when disturbed, has enlarged hind legs,
and is defoliating lettuce. What Order does it belong to?
A. Orthoptera
B. Coleoptera
