Entomology: Insect Morphology, Classification and Life Cycles MCQs 2026

The triangular dorsal plate between wing bases of many hemipterans is the

1. A clypeus ✓
2. B scape ✓
3. C pretarsus ✓
4. D scutellum ✓

A dichotomous key identifies insects by using

1. A random chemical sprays ✓
2. B paired contrasting characters ✓
3. C crop yield records only ✓
4. D soil texture classes only ✓

The taxonomic rank below order and above genus is

1. A family ✓
2. B class ✓
3. C phylum ✓
4. D species ✓

Paurometabolous insects have nymphs that

1. A are maggots without legs ✓
2. B always live inside cocoons ✓
3. C are aquatic while adults are terrestrial only ✓
4. D resemble adults and share the same habitat ✓

Ametabolous development is characterized by

1. A complete metamorphosis with pupae ✓
2. B nymphs with wing pads only ✓
3. C absence of metamorphosis ✓
4. D adult emergence from a puparium ✓

Diapause in insects is best defined as

1. A a type of chewing mouthpart ✓
2. B a hormonally regulated dormancy ✓
3. C a bacterial disease of larvae ✓
4. D a wing vein pattern only ✓

The shed old cuticle after molting is called

1. A exuviae ✓
2. B chorion ✓
3. C frass ✓
4. D honeydew ✓

The developmental stage between two molts is an

1. A ocellus ✓
2. B elytron ✓
3. C ovariole ✓
4. D instar ✓

Juvenile hormone generally maintains

1. A wing venation only ✓
2. B egg shell hardness only ✓
3. C immature characters ✓
4. D adult diapause only ✓

Molting in insects is controlled mainly by the hormone

1. A insulin ✓
2. B ecdysone ✓
3. C thyroxine ✓
4. D adrenaline ✓

The lateral plates of insect segments are called

1. A pleurites ✓
2. B tergites ✓
3. C sternites ✓
4. D labella ✓

The ventral plates of insect segments are called

1. A tergites ✓
2. B elytra ✓
3. C ocelli ✓
4. D sternites ✓

The hardened dorsal plates of insect segments are called

1. A sternites ✓
2. B pleurites ✓
3. C tergites ✓
4. D spiracles ✓

Clavate antennae are

1. A flat and leaf-like along the full length ✓
2. B gradually clubbed toward the tip ✓
3. C feather-like with long branches ✓
4. D reduced to a single spine ✓

Setaceous antennae are

1. A bristle-like ✓
2. B comb-like ✓
3. C leaf-like ✓
4. D elbowed and clubbed ✓

A plumose antenna is

1. A clubbed at the end ✓
2. B short and bristle-like ✓
3. C elbowed with a long scape ✓
4. D feather-like ✓

Cockroaches belong to the order

1. A Diptera ✓
2. B Blattodea ✓
3. C Lepidoptera ✓
4. D Coleoptera ✓

True bugs belong to the order

1. A Orthoptera ✓
2. B Odonata ✓
3. C Hemiptera ✓
4. D Thysanoptera ✓

Beetles belong to the order

1. A Hymenoptera ✓
2. B Neuroptera ✓
3. C Isoptera ✓
4. D Coleoptera ✓

Flies with one pair of functional wings belong to the order

1. A Diptera ✓
2. B Lepidoptera ✓
3. C Coleoptera ✓
4. D Hemiptera ✓

A geniculate antenna is best described as

1. A feather-like ✓
2. B saw-like ✓
3. C elbowed ✓
4. D thread-like without bends ✓

The insect body is divided into three main regions called

1. A head, thorax and abdomen ✓
2. B cephalothorax, tail and foot ✓
3. C root, stem and leaf ✓
4. D shell, mantle and foot ✓

The number of legs in an adult insect is

1. A two pairs ✓
2. B three pairs ✓
3. C four pairs ✓
4. D five pairs ✓

Insect antennae function primarily as

1. A walking appendages ✓
2. B respiratory tubes ✓
3. C sensory organs ✓
4. D digestive glands ✓

The outer skeleton of insects is mainly composed of

1. A cellulose ✓
2. B keratin ✓
3. C silica ✓
4. D chitin ✓

The insect thorax bears the

1. A legs and wings ✓
2. B mouthparts and antennae only ✓
3. C ovaries and Malpighian tubules only ✓
4. D cerci and spiracles only ✓

Mandibulate mouthparts are primarily adapted for

1. A siphoning nectar only ✓
2. B chewing ✓
3. C piercing and sucking only ✓
4. D sponging liquid only ✓

Siphoning mouthparts are characteristic of adult

1. A termites and lice ✓
2. B grasshoppers and crickets ✓
3. C butterflies and moths ✓
4. D beetle larvae only ✓

Piercing-sucking mouthparts are typical of

1. A honeybee workers only ✓
2. B dragonfly adults only ✓
3. C silkworm pupae only ✓
4. D aphids and mosquitoes ✓

A compound eye is made up of many units called

1. A ommatidia ✓
2. B spiracles ✓
3. C tergites ✓
4. D elytra ✓

Simple eyes of many insects are called

1. A cerci ✓
2. B ocelli ✓
3. C palps ✓
4. D claspers ✓

The main respiratory openings on the insect body are

1. A nephridia ✓
2. B stomata ✓
3. C spiracles ✓
4. D alveoli ✓

Insects conduct respiration through a system of

1. A lungs ✓
2. B gills only ✓
3. C book lungs only ✓
4. D tracheae ✓

The open circulatory fluid of insects is called

1. A hemolymph ✓
2. B plasma sap ✓
3. C lymph node fluid ✓
4. D xylem water ✓

Malpighian tubules function mainly in

1. A sound production only ✓
2. B excretion and osmoregulation ✓
3. C wing folding only ✓
4. D egg fertilization only ✓

The insect nervous system includes a ventral

1. A notochord ✓
2. B spinal column ✓
3. C nerve cord ✓
4. D mycelial strand ✓

Complete metamorphosis is termed

1. A ametabolous development ✓
2. B paurometabolous development ✓
3. C direct segmentation ✓
4. D holometabolous development ✓

Incomplete metamorphosis is termed

1. A hemimetabolous development ✓
2. B holometabolous development ✓
3. C embryogenesis only ✓
4. D diapause development ✓

The immature stage of a grasshopper is called a

1. A maggot ✓
2. B nymph ✓
3. C pupa ✓
4. D grub ✓

The immature feeding stage of a butterfly is called a

1. A nymph only ✓
2. B adult worker ✓
3. C larva or caterpillar ✓
4. D puparium ✓

The resting transformative stage in holometabolous insects is the

1. A nymph ✓
2. B crawler ✓
3. C queen ✓
4. D pupa ✓

An egg, larva, pupa and adult sequence occurs in

1. A complete metamorphosis ✓
2. B simple cell division ✓
3. C direct seed germination ✓
4. D incomplete digestion ✓

The paired terminal abdominal appendages in many insects are called

1. A palpi ✓
2. B cerci ✓
3. C spiracles ✓
4. D mandibles ✓

Moths and butterflies belong to the order

1. A Blattodea ✓
2. B Lepidoptera ✓
3. C Dermaptera ✓
4. D Phasmatodea ✓

Bees, wasps and ants belong to the order

1. A Diptera ✓
2. B Hemiptera ✓
3. C Hymenoptera ✓
4. D Orthoptera ✓

Grasshoppers and crickets belong to the order

1. A Odonata ✓
2. B Coleoptera ✓
3. C Siphonaptera ✓
4. D Orthoptera ✓

Dragonflies and damselflies belong to the order

1. A Odonata ✓
2. B Mantodea ✓
3. C Diptera ✓
4. D Plecoptera ✓

The hardened forewings of beetles are called

1. A halteres ✓
2. B elytra ✓
3. C cerci ✓
4. D ocelli ✓

The balancing organs of true flies are called

1. A mandibles ✓
2. B maxillae ✓
3. C halteres ✓
4. D tegmina ✓

The tarsus is part of the insect

1. A leg ✓
2. B antenna ✓
3. C wing vein ✓
4. D digestive tract ✓

Agricultural entomology studies

1. A only fish taxonomy ✓
2. B only soil texture triangles ✓
3. C insects and their relation to crops and control ✓
4. D only tractor gearboxes ✓

Insects are characterized by

1. A three body regions, six legs and usually wings in adults ✓
2. B eight legs like spiders ✓
3. C no segmented bodies ✓
4. D only two legs ✓

Metamorphosis in insects may be

1. A complete (egg-larva-pupa-adult) or incomplete ✓
2. B absent in all pests ✓
3. C only a plant process ✓
4. D identical to seed germination ✓

Chewing mouthparts are typical of

1. A aphids and whiteflies (piercing-sucking) ✓
2. B bollworms, grasshoppers and many beetles ✓
3. C mosquitoes only as larvae identical ✓
4. D butterflies that only sip forever as larvae ✓

Piercing-sucking insects include

1. A locusts with chewing mandibles only ✓
2. B stem borers that only chew tunnels ✓
3. C aphids, whiteflies, jassids and plant bugs ✓
4. D cutworms that cut seedlings ✓

Cotton bollworm (Helicoverpa) damages

1. A squares, flowers and bolls ✓
2. B only wheat roots exclusively ✓
3. C only citrus leaves as rust ✓
4. D only fish ponds ✓

Whitefly is notorious in Pakistan cotton for

1. A causing only stem rust pustules ✓
2. B replacing grains with smut ✓
3. C sucking sap and transmitting cotton leaf curl virus ✓
4. D cutting seedlings like cutworm ✓

American bollworm is another name often used for

1. A Pectinophora gossypiella only ✓
2. B Helicoverpa armigera ✓
3. C Sitophilus oryzae only ✓
4. D Apis mellifera ✓

Aphids damage crops mainly by

1. A boring into wood like termites only ✓
2. B cutting stems at soil line only ✓
3. C mining only citrus rind exclusively ✓
4. D sucking sap and transmitting viruses; honeydew/sooty mold ✓

Jassids (leafhoppers) on cotton cause

1. A only smut of wheat ✓
2. B only root knots ✓
3. C leaf curling/yellowing from sap sucking ✓
4. D only fruit fly stings on mango exclusively ✓

Thrips injure plants by

1. A chewing entire bolls like bollworm larvae always ✓
2. B making rust pustules ✓
3. C producing bacterial ooze ✓
4. D rasping and sucking tender tissues ✓

Stem borers are especially important in

1. A only stored grain weevils indoors ✓
2. B rice and sugarcane (and some other cereals) ✓
3. C only honey bees ✓
4. D only earthworms ✓

Rice stem borer damage symptoms include

1. A only citrus canker lesions ✓
2. B dead hearts and white ears ✓
3. C only powdery mildew mats ✓
4. D only root galls ✓

Shoot fly is a notable pest of

1. A mature mango trunks only ✓
2. B sorghum/maize seedlings (dead hearts) ✓
3. C stored wheat only ✓
4. D adult cattle only ✓

Army worms and cutworms typically

1. A suck phloem like whitefly only ✓
2. B vector CLCuD primarily ✓
3. C form smut balls ✓
4. D cut or defoliate seedlings and plants, often at night ✓

Fruit flies infest

1. A only cotton roots ✓
2. B only wheat ears as rust ✓
3. C only potato tubers as blight ✓
4. D ripening fruits such as mango and guava ✓

Red palm weevil is a destructive pest of

1. A wheat only ✓
2. B potato only ✓
3. C date palm and related palms ✓
4. D cotton squares only ✓

Termites in agriculture damage

1. A wooden structures, roots and sometimes crops/seedlings ✓
2. B only adult flying whiteflies ✓
3. C only rust spores ✓
4. D only drip filters exclusively ✓

Stored grain pests include

1. A only field bollworms on green bolls ✓
2. B only fruit flies on trees ✓
3. C weevils, beetles and moths attacking grain in storage ✓
4. D only stem borers in standing rice ✓

Locusts are dangerous because they

1. A swarm and devour vegetation over large areas ✓
2. B fix only microscopic leaf spots ✓
3. C transmit only soil nematodes ✓
4. D fix nitrogen for legumes ✓

Beneficial insects include

1. A predators, parasitoids and pollinators ✓
2. B only bollworms ✓
3. C only whiteflies ✓
4. D only stem borers ✓

Ladybird beetles are valued as

1. A predators of aphids and soft-bodied pests ✓
2. B primary cotton bollworms ✓
3. C fruit fly maggots ✓
4. D stored grain weevils ✓

Trichogramma wasps are used as

1. A chewing defoliators ✓
2. B sap-sucking vectors of CLCuD ✓
3. C stored grain primary pests ✓
4. D egg parasitoids in biological control ✓

Honey bee (Apis) is important for

1. A pollination and honey production ✓
2. B causing cotton leaf curl ✓
3. C boring rice stems ✓
4. D cutting potato seed pieces as cutworm ✓

Insecticides are chemicals that

1. A cure only fungal rusts ✓
2. B kill or repel insect pests ✓
3. C add nitrogen to soil ✓
4. D raise soil organic matter directly ✓

Systemic insecticides are taken up by

1. A only the soil surface film forever without uptake ✓
2. B plant tissues and can affect feeding insects ✓
3. C only tractor tires ✓
4. D only canal water without plants ✓

Contact insecticides act when

1. A insects touch treated surfaces or spray droplets ✓
2. B only after fungi form pustules ✓
3. C only via viral replication ✓
4. D only through nematode stylet in roots exclusively ✓

Stomach poisons affect insects that

1. A ingest treated plant material ✓
2. B never feed ✓
3. C only walk on untreated glass ✓
4. D only breathe pure nitrogen ✓

Insect growth regulators (IGRs) disrupt

1. A photosynthesis in wheat ✓
2. B nitrogen fixation in Rhizobium ✓
3. C soil texture classes ✓
4. D molting/development rather than quick knockdown alone ✓

Pesticide resistance develops when

1. A pests are never exposed to chemicals ✓
2. B repeated selection favors tolerant pest populations ✓
3. C only resistant crop varieties are banned ✓
4. D refugia are perfectly managed always ✓

Economic Injury Level (EIL) is the pest density at which

1. A pests first appear anywhere ✓
2. B zero insects remain ✓
3. C damage equals cost of control ✓
4. D fungicides must be sprayed weekly always ✓

Economic Threshold (ETL) is typically

1. A the pest level at which control should be applied to prevent reaching EIL ✓
2. B the same as zero insects ✓
3. C always 100% infestation ✓
4. D irrelevant to IPM ✓

Scouting/monitoring in entomology means

1. A never visiting fields ✓
2. B regular field inspection of pest and beneficial populations ✓
3. C spraying on fixed dates only ✓
4. D ignoring insect counts ✓

Pheromone traps are used to

1. A irrigate orchards ✓
2. B monitor or mass-trap certain moth pests ✓
3. C apply nitrogen ✓
4. D measure soil EC ✓

Light traps attract

1. A only soil nematodes ✓
2. B only fungal spores ✓
3. C many night-flying insects for monitoring ✓
4. D only fish fingerlings ✓

Cultural control examples include

1. A only calendar insecticide sprays ✓
2. B only ignoring residues ✓
3. C crop rotation, sowing date adjustment and destruction of alternate hosts ✓
4. D only banning all predators ✓

Mechanical control includes

1. A only systemic seed treatments ✓
2. B only aerial ULV always ✓
3. C only ignoring ETL ✓
4. D hand picking, barriers, traps and destruction of infested parts ✓

Biological control uses

1. A only broad-spectrum sprays daily ✓
2. B only soil solarization for insects exclusively ✓
3. C only resistant varieties with zero enemies ✓
4. D natural enemies to suppress pests ✓

Selective insecticides are preferred in IPM because they

1. A kill all insects including bees always ✓
2. B have no label instructions ✓
3. C increase resistance fastest always ✓
4. D spare many beneficials compared with broad-spectrum products ✓

Neem-based products are examples of

1. A botanical insecticides used in eco-friendly programs ✓
2. B synthetic pyrethroids only ✓
3. C organophosphate nerve gases only ✓
4. D fungal rust spores ✓

Quarantine pests are those that

1. A are always beneficial pollinators ✓
2. B never travel with produce ✓
3. C are ignored by SPS rules ✓
4. D are regulated to prevent entry/spread across regions ✓

Integrated control of cotton sucking pests emphasizes

1. A daily sprays regardless of counts ✓
2. B destroying all beneficials first ✓
3. C monitoring, thresholds and conservation of natural enemies ✓
4. D planting only without scouting ✓

Fall armyworm has become important on

1. A only date palm trunks ✓
2. B maize and other cereals/grasses ✓
3. C only stored mung in godowns exclusively ✓
4. D only citrus canker lesions ✓

Mealybugs damage plants by

1. A chewing bolls like Helicoverpa only ✓
2. B mining leaf mesophyll only as leaf miners always ✓
3. C sucking sap and secreting honeydew ✓
4. D cutting stems at ground level ✓

Scale insects are typically

1. A highly mobile locust swarms ✓
2. B sedentary sap feeders on stems/leaves ✓
3. C soil-only white grubs always ✓
4. D free-living honey bees ✓

Leaf miners create

1. A serpentine or blotch mines inside leaves ✓
2. B smut balls in florets ✓
3. C rust uredinia on wheat ✓
4. D galls only on roots always ✓

Safe insecticide use requires

1. A mixing by guesswork ✓
2. B correct dose, PPE, PHI and label compliance ✓
3. C spraying upwind into face without PPE ✓
4. D ignoring pre-harvest intervals ✓

Mode of action rotation helps to

1. A speed resistance selection ✓
2. B eliminate all monitoring needs ✓
3. C replace ETL concepts ✓
4. D delay insecticide resistance ✓

The immature damaging stage of most Lepidopteran pests is the

1. A only the egg that never feeds ✓
2. B only the pupa that feeds heavily ✓
3. C adult butterfly that chews bolls like larvae ✓
4. D larva (caterpillar) ✓