RPSC Agriculture Research Officer (Entomology) - 2022

Properties 2 and 3 are correct physical attributes of lac (fusible on heat, excellent natural adhesive); statements 1, 4, 5, and 6 are incorrect because: lac is completely insoluble in water but soluble in alcohol (1 is wrong); possesses strong binding properties with alcohol (4 is wrong); is a poor conductor / excellent insulator of heat and electricity (5 is wrong); and dissolves readily in weak alkalies like aqueous ammonia or sodium carbonate (6 is wrong).

• 1, 4, 5 and 6 only: Correct code identifying all four false statements.
• 2, 4 and 5 only: Incorrect because statement 2 is true.
• 1, 2, 5 and 6 only: Incorrect because statement 2 is true.
• All of the above statements: Incorrect because 2 and 3 are true.

All three insects - Blow flies (family Calliphoridae), Green bottle flies (Lucilia sericata), and Flesh flies (family Sarcophagidae) - are obligate necrophagous/carrion-feeding dipterans that breed in and consume decaying animal carcasses, playing vital roles in forensic entomology.

• Blow flies: Prominent carrion-feeding necrophagous insects.
• Common Green bottle fly: Metallic calliphorid whose maggots feed on carrion and dead tissue.
• Flesh fly: Sarcophagid flies whose viviparous maggots develop in decaying animal flesh.
• All of the above: All three flies are primary carrion feeders.

During honey ripening in the honey stomach, the bee enzyme invertase hydrolyses floral sucrose into simple reducing sugars: levulose (D-fructose, ~38-40%) and dextrose (D-glucose, ~31-35%), while transglucosylation reactions also synthesize minor amounts of maltose (~7%) and other oligosaccharides.

• Dextrose: Major monosaccharide component of honey (glucose).
• Maltose: Minor disaccharide sugar synthesized during enzyme ripening of honey.
• Levulose: The predominant sweetest monosaccharide in honey (fructose).
• All of the above: All three sugars are formed enzymatically during the nectar-to-honey conversion process.

• The Western or European honey bee (Apis mellifera L.) evolved in tropical/subtropical Africa and the Middle East, subsequently radiating into Europe and Asia into distinct geographic subspecies.
• The Italian bee (Apis mellifera ligustica), celebrated for its gentle temperament, prolific brood rearing, and high honey yield, originated specifically in peninsular Italy.
• Because of its commercial superiority, A. mellifera was introduced into India in 1962 (at Nagrota Bagwan, Himachal Pradesh by PAU/ICAR).
• Apis cerana indica is native to the Indian subcontinent.

All three statements regarding the botanical insecticide sabadilla are factually correct: it is derived from ground seeds of the lily Schoenocaulon officinale (containing veratrum alkaloids, veratridine and cevadine); it breaks down rapidly upon UV exposure without leaving persistent toxic residues; and because of its acute toxicity to foraging honeybees, evening spraying is recommended.

• Sabadilla is highly toxic to honeybee and should only be used in the evening: True statement.
• Sabadilla degrades rapidly in sunlight and air leaving no harmful residues: True statement.
• Sabadilla comes from the seeds of a lily (Schoenocaulon officinale): True statement.
• All of the above: All three statements are accurate.