ICAR AIEEA PG Entomology 14 July 2023 Shift-1 Paper

Agroecosystem stability and natural enemy conservation:

• Statement (I) is correct: Perennial cropping systems (such as orchards, agroforestry, plantations) provide continuous microhabitats, alternative food sources (pollen, nectar, alternative prey), and stable nesting sites with minimal tillage, plowing, and seasonal clear-cutting, fostering diverse and stable populations of predators and parasitoids.
• Statement (II) is directly contradicted by ecological theory and is incorrect.

Semiochemical terminology (Brown, Eisner, and Whittaker, 1970):

• Apneumone: A chemical substance emitted by non-living material (e.g., dung, rotting wood, rotting meat, animal carcasses) that evokes a behavioral or physiological reaction adaptively favorable to a receiving organism (e.g., an ichneumonid parasitoid searching for wood-boring larvae), but detrimental to an organism of another species found in/on that non-living material.
• Kairomone: Emitted by an organism of one species, benefits the receiver of another species (e.g., host odors attracting parasitoids).
• Allomone: Emitted by an organism of one species, benefits the emitter.
• Synomone: Benefits both emitter and receiver.

Intercropping evaluation indices:

• LER stands for Land Equivalent Ratio.
• Definition: LER is defined as the relative land area under sole cropping required to produce the same yields as obtained under intercropping at the same level of management: $\text{LER} = \frac{Y_{ab}}{Y_{aa}} + \frac{Y_{ba}}{Y_{bb}}$.
• An $\text{LER} \gt 1.0$ indicates yield advantage from intercropping, while $\text{LER} \lt 1.0$ reflects mutual inhibition or disadvantage.