Which of the following pairs is not correctly matched? Crop : Insect-pest

In agricultural science, insect pests are typically documented against the crop(s) where they are most prevalent and economically significant, even though some pests are polyphagous and may occasionally be recorded on other crops too. "Odd pair" questions on crop-pest matching test whether a listed pairing reflects the crop each pest is principally and most commonly associated with in standard references.

Checking each pairing here against the recorded major pests for these four crops:

• Groundnut: its major, most frequently documented pests are the Red Hairy Caterpillar, Aphids, and White Grub — Pod borer is not typically classed among these principal pests for groundnut in standard agricultural references.

• Gram: Pod borer (Helicoverpa armigera) is documented as the principal pest of gram, damaging pods and causing significant yield loss — a correctly matched pairing.

• Paddy: Banka is documented among paddy's recognised pests in standard agricultural references — a correctly matched pairing.

• Maize: Stem borer (Chilo partellus) is a documented pest that tunnels into the stem and weakens the plant — a correctly matched pairing.

Against these standard references, the Gram, Paddy, and Maize pairings hold as principal pest-crop associations, while Groundnut is not principally associated with Pod borer — making Groundnut : Pod borer the pairing that is not correctly matched by this convention.