Question: Which of the following weeds act as alternate hosts for the gram caterpillar (Helicoverpa armigera) of redgram (Cajanus cajan)?
Options:
Amaranth
Datura
Both A and B
none of these
✅ EXPLANATION: Amaranthus and Datura species have both been confirmed to serve as alternate hosts for the gram caterpillar, a polyphagous pest that can feed on a wide range of plants. These weeds provide food and shelter during the caterpillar's development stages, allowing it to survive and reproduce even when redgram is not available.