UPHESC Assistant Professor Entomology PYQs

Concept: White grub, Holotrichia consanguinea / H. serrata (Scarabaeidae: Melolonthinae), is univoltine.

1. Adults emerge with the first monsoon showers (May–June), lay eggs in soil; grubs feed on roots till September–October.
2. It pupates and passes the winter in soil as adult/pupa – only one generation per year.

Short trick: Monsoon beetle → one generation a year.

Concept: The term/idea 'integrated control' was first used by Hoskins, Borden and Michelbacher (1939) – chemical control should supplement biological control.

1. Stern, Smith, van den Bosch and Hagen (1959) defined integrated control and gave the ET/EIL concept.
2. The term IPM was used by Smith and van den Bosch (1967) and became popular in 1970s.
3. Paul Müller discovered insecticidal property of DDT in 1939 (not 1937) – unrelated.

Short trick: 1939 Hoskins = integrated control idea; 1959 Stern = ETL; 1967 = IPM term.

Concept: Imidacloprid is a neonicotinoid (IRAC Group 4A) – it acts as an agonist of the nicotinic acetylcholine receptor (nAChR) in the insect CNS.

1. It binds the receptor like acetylcholine but is not broken down by AChE → continuous stimulation, paralysis, death.
2. AChE inhibition = organophosphates/carbamates; mitochondrial electron transport inhibitors = fenpyroximate, rotenone; octopamine agonist = amitraz.

Short trick: Neonicotinoid = nicotine-like = nAChR agonist.

Concept: Pedigo's formula: EIL = C / (V × I × D × K).

1. C = cost of control per unit area; V = market value per unit produce.
2. I = injury units per insect (crop injury per pest density); D = damage (yield loss) per unit injury.
3. K = proportionate reduction of injury by control (often taken as 1, giving EIL = C/VID).

Short trick: C-V-I-D-K: Cost, Value, Injury/insect, Damage/injury, Kill-proportion.

Concept: Painter's three mechanisms of host plant resistance: antixenosis (non-preference), antibiosis and tolerance.

1. Antibiosis = adverse effect of the plant on the insect's biology – reduced growth, survival, fecundity, prolonged development.
2. Antixenosis affects the insect's behaviour (host selection); tolerance is the plant's ability to withstand/recover from damage.

Short trick: Anti-BIO-sis → affects BIOlogy.

Concept: Fipronil is a phenylpyrazole (fiprole) insecticide – IRAC Group 2B, a GABA-gated chloride channel blocker.

1. Oxadiazine = indoxacarb (sodium channel blocker).
2. Neonicotinoids (imidacloprid) and thianicotinyls (thiamethoxam) act on nAChR.

Short trick: FIProle = FIPronil = Phenylpyrazole.

Concept: LC50 = concentration of a toxicant that kills 50% of the test population.

1. If a smaller concentration kills half the insects, the chemical is more potent.
2. So toxicity is inversely related to LC50/LD50: low LC50 → more toxic.

Short trick: Low LC50 = little needed to kill = more toxic.

Concept: Allelochemicals act between species and are named by who benefits.

1. Kairomone – benefits the receiver only (e.g. host odour guiding a parasitoid to its host).
2. Allomone – benefits the emitter only (e.g. defensive secretions); Synomone – benefits both (e.g. floral scent and pollinator).
3. Apneumone comes from a non-living source.

Short trick: Kairomone = Kamaayi receiver ki; Allomone = Apna (emitter) faayda; Synomone = Saajha.

Concept: The Insecticides Act, 1968 regulates import, manufacture, sale, transport, distribution and use of insecticides in India.

1. The Act and the Insecticides Rules (1971) were brought into force from 1 August 1971.
2. It set up the Central Insecticides Board (CIB) and the Registration Committee (RC).

Short trick: Act 1968 → Rules + enforcement 1971.

Concept: Pesticides are named after the target: Avi = bird.

1. Avicides are chemicals used against birds – to kill or repel them (e.g. anthraquinone, methiocarb, 4-aminopyridine).
2. Acaricides – mites; molluscicides – snails/slugs; nematicides – nematodes.

Short trick: Avis (Latin) = bird → avicide.

Concept: Rice weevil is Sitophilus oryzae (Curculionidae) – a primary internal feeder of rice, wheat, maize.

1. Sitophilus granarius = granary weevil (wingless, temperate).
2. Sitotroga cerealella = Angoumois grain moth; Aspidiotus hartii = yam scale.

Short trick: oryzae = Oryza (rice) → rice weevil.

Concept: Insects, moulds and seed respiration increase sharply above ~10–12% moisture.

1. For long-term safe storage, seeds should be dried to below 10% moisture (8–10%; for sealed containers even lower).
2. At 12–15% grain can be kept only for short periods; most stored-grain insects cannot multiply below ~9–10% moisture.

Short trick: Long-term seed store → moisture < 10%.

Concept: Angoumois grain moth is Sitotroga cerealella (Gelechiidae) – an internal feeder of paddy, maize, wheat; named after Angoumois province of France.

1. Corcyra cephalonica = rice moth; Ephestia cautella = almond/fig moth; Plodia interpunctella = Indian meal moth (all Pyralidae, external feeders).

Short trick: Sitotroga cerealella – 'cereal' → grain moth.

Concept: Chemosterilants reduce rodent fertility instead of killing.

1. Furadantin (nitrofurantoin) has been used as an antifertility (chemosterilant) agent for rats; others include α-chlorohydrin and mestranol.
2. Phosphine – fumigant (from aluminium/zinc phosphide); bromadiolone – second-generation anticoagulant; barium carbonate – acute rodenticide.

Short trick: Kills = rodenticide; stops breeding = chemosterilant (furadantin, α-chlorohydrin).

Concept: Khapra beetle, Trogoderma granarium (Dermestidae), is adapted to hot, dry conditions.

1. It thrives at 33–37 °C and can develop at very low humidity (grain moisture as low as 2%); larvae can enter diapause for years.
2. It is a serious quarantine pest in NW India (Rajasthan, Punjab); rice weevil and grain moth need moister grain.

Short trick: Khapra = hot & dry (Rajasthan) pest.

Concept: Pulse beetle Callosobruchus chinensis (Chrysomelidae: Bruchinae) has long antennae with saw-tooth-like segments – serrate (pectinate in males).

1. Lamellate antennae = scarab beetles (white grub); flabellate = some beetles (e.g. Rhipiceridae); capitate = butterflies, red flour beetle-type clubs.
2. Serrate antenna is a key character used to identify bruchids in stored pulses.

Short trick: Pulse beetle → saw-like (serrate) antennae.

Concept: Khapra beetle Trogoderma granarium belongs to Dermestidae (skin/larder beetles).

1. Only the hairy larvae (grubs) damage grain; adults do not feed.
2. Curculionidae = weevils (Sitophilus); Tenebrionidae = flour beetles (Tribolium).

Short trick: Hairy grub, dry places → Dermestidae.

Concept: Mulberry silkworm Bombyx mori belongs to Bombycidae (Lepidoptera).

1. Non-mulberry silkworms – tasar (Antheraea mylitta), muga (A. assamensis), eri (Samia ricini) – belong to Saturniidae.
2. Formicidae = ants; Tortricidae = leaf-roller moths.

Short trick: Bombyx → Bombycidae; tasar/muga/eri → Saturniidae.

Concept: Bee venom (apitoxin) contains melittin, apamin, phospholipase A2 etc. and is used in apitherapy.

1. Its classical and most cited medical use is in treating rheumatism and arthritis (joint pain).
2. Honey and propolis are used for wounds/ulcers and cough – not venom.

Short trick: Bee sting therapy → rheumatism/arthritis.

Concept: Moriculture = cultivation of mulberry (Morus spp.) to produce leaves for silkworm rearing.

1. Sericulture = moriculture + silkworm rearing + reeling.
2. Lac culture = rearing lac insect Kerria lacca; apiculture = beekeeping.

Short trick: Morus → moriculture.