UPHESC Assistant Professor Entomology PYQs

Concept: Worker honey bees have four pairs of wax glands on the ventral side (sternites) of abdominal segments 4 to 7.

1. Wax is secreted as thin scales in 'wax pockets' when workers are about 12–18 days old.
2. Queens and drones lack functional wax glands.

Short trick: 4 pairs of wax glands on segments 4–7.

Concept: Royal jelly is secreted by hypopharyngeal and mandibular glands of nurse bees and fed to queen larvae.

1. Besides water (~60–70%), its main constituent is protein (major royal jelly proteins, about 12–15% fresh, ~30–40% of dry matter).
2. Sugars (10–16%) and lipids (3–6%, mainly 10-HDA) are present in lesser amounts.
3. It is the high-protein 'queen food'.

Short trick: Royal jelly = protein-rich queen food.

Concept: Floral fidelity (flower constancy) is the tendency of a forager bee to keep visiting flowers of the same species while that source lasts.

1. It makes honey bees efficient pollinators – pollen is carried to flowers of the same species.
2. Bee pasture/bee forage = the flora providing nectar and pollen to bees.

Short trick: Fidelity = loyalty to one flower species.

Concept: Saprophagous (scavenger) insects feed on dead and decaying organic matter – plant or animal.

1. Examples: blow fly and flesh fly maggots, carrion and burying beetles, dung beetles.
2. Carnivores/insectivores eat living animals/insects; phytophagous insects feed on living plants.

Short trick: Sapro = rotten → saprophagous.

Concept: Pebrine is a microsporidian disease of the silkworm Bombyx mori, caused by Nosema bombycis.

1. It is transmitted transovarially (mother to egg) and orally; it devastated the French silk industry and was studied by Louis Pasteur (1865–70).
2. Control: mother-moth examination (Pasteur's method) and disease-free layings (DFLs).

Short trick: Pebrine – pepper-like black spots – silkworm – Pasteur.

Concept: A soil injector (soil injecting gun) is a hand pump whose lance ends in a pointed hollow probe that is pushed into the soil.

1. It delivers measured doses of soil fumigants/nematicides (e.g. against nematodes, termites, soil insects) below the surface.
2. Smoke generators, mist blowers and spray blowers apply chemicals into air/foliage, not into soil.

Short trick: Lance into soil → soil injector.

Concept: The Electrodyn sprayer is an electrostatic sprayer: droplets are electrically charged and attracted to the plant (earthed target).

1. Charged droplets curve around leaves and deposit on both upper and lower surfaces – the 'wrap-around effect'.
2. This gives better coverage with less drift and very low volume; ordinary hydraulic/pneumatic sprayers lack this effect.

Short trick: Charge → attraction → wrap-around (Electrodyn).

Concept: Low-volume (high-concentration) spraying needs very fine droplets carried by a strong air blast.

1. Such sprayers – mist blowers, power knapsack sprayers, air-blast sprayers – are driven by engines (power machinery).
2. Hand compression, foot and rocker pumps are manual high-volume hydraulic sprayers.

Short trick: Low volume, fine mist → engine-driven (power) sprayer.

Concept: A duster consists of a hopper (container for dust), an agitator, a feed/metering device, a blower/fan and a delivery tube.

1. The hopper of a duster corresponds to the tank of a sprayer.
2. Pressure chamber and nozzle are sprayer parts.

Short trick: Sprayer: tank; Duster: hopper.

Concept: Droplets are classified by volume median diameter (VMD).

1. Aerosol: 0.1–50 µm; mist: 50–100 µm; fine spray: 100–250 µm; medium/coarse spray: >250 µm.
2. Aerosols are used for space treatment (mosquitoes, flies, warehouses).

Short trick: Aerosol < 50 < mist < 100 < fine spray.

Concept: High-volume (hydraulic power) sprayers pump large volumes of dilute spray at high pressure, roughly 20–55 kg/cm².

1. Converting: 1 kg/cm² ≈ 14.2 psi, so 20–55 kg/cm² ≈ 300–800 psi.
2. Such pressure forces liquid through the nozzle to break it into droplets and to reach tall trees (orchard sprayers).
3. Manual pumps (rocker, foot) develop only about 7–17 kg/cm² (100–250 psi).

Short trick: High-volume power sprayer: 300–800 psi.

Concept: A hollow-cone/cone nozzle consists of a nozzle body, swirl plate (core), washer, disc with orifice and cap.

1. The swirl plate has slanted grooves that impart a rotational (swirling) motion to the liquid, which then breaks into a cone of droplets on leaving the orifice.

Short trick: Swirl = spin → cone nozzle.

Concept: Tomato spotted wilt virus (Tospovirus/Orthotospovirus) is transmitted only by thrips, notably Thrips tabaci and Frankliniella occidentalis.

1. Thrips acquire the virus as larvae and transmit as adults in a persistent-propagative manner.
2. WSMV is transmitted by the eriophyid mite Aceria tosichella; PSTVd spreads mechanically/through seed tubers (aphids only with PLRV).

Short trick: Tospo → Thrips (T–T).

Concept: Whiteflies (e.g. Bemisia tabaci) belong to Aleyrodidae (Hemiptera: Sternorrhyncha).

1. Pseudococcidae = mealybugs; Cicadellidae = leafhoppers; Eriophyidae = gall/rust mites (Acari, not insects).

Short trick: Aleyrodes (Greek 'flour-like') → white mealy wings → Aleyrodidae.

Concept: Bhindi (okra) yellow vein mosaic virus is a begomovirus (Geminiviridae).

1. Begomoviruses are transmitted by the whitefly Bemisia tabaci in a persistent, circulative manner.
2. Aphids transmit potyviruses/cucumoviruses; thrips transmit tospoviruses.

Short trick: Yellow vein / leaf curl (gemini) → whitefly.

Concept: Sugarcane mosaic virus (Potyvirus) is transmitted non-persistently by aphids, chiefly the corn leaf aphid Rhopalosiphum maidis (also Melanaphis sacchari).

1. It also spreads through infected setts.
2. Nephotettix transmits rice tungro; Thrips tabaci transmits TSWV.

Short trick: Sugarcane mosaic → maize aphid (R. maidis).

Concept: Citrus tristeza virus (Closterovirus) is transmitted semi-persistently by aphids; the brown citrus aphid Toxoptera citricida is the most efficient vector.

1. Diaphorina citri (Asian citrus psyllid) and Trioza erytreae (African psyllid) transmit citrus greening (huanglongbing) bacterium.

Short trick: Tristeza → Toxoptera (T–T); greening → psyllid.

Concept: Whitefly-borne begomoviruses (leaf curl, yellow vein mosaic) are transmitted in a persistent, circulative manner.

1. The virus is ingested, passes through the gut into the haemolymph, reaches the salivary glands and is injected with saliva.
2. Hence there is a latent period and the whitefly stays viruliferous for long (often for life).
3. Non-persistent (stylet-borne) transmission is typical of aphids and potyviruses.

Short trick: Whitefly + gemini virus = persistent circulative.

Concept: Onion thrips Thrips tabaci (Thripidae): egg → 2 larval instars → prepupa → pupa → adult.

1. The mature second-instar larva drops to the ground and the prepupal and pupal stages are passed in the soil (a few cm deep).
2. So soil application/irrigation and ploughing help reduce the population.

Short trick: Thrips: feed on plant, pupate in soil.

Concept: Sweet potato weevil, Cylas formicarius (Brentidae/Curculionidae), is the key pest of sweet potato (printed as 'termicarius').

1. Grubs tunnel in vines and tubers; infested tubers turn bitter and unfit for eating.
2. Amrasca biguttula biguttula = cotton/okra leafhopper; Agrotis ipsilon = cutworm; Phthorimaea operculella = potato tuber moth.

Short trick: Cylas – ant-like ('formica') weevil – sweet potato.