DENDROLOGY

Detailed explanation-1: -Whiteflies, thrips, mealybugs, plant hoppers, grasshoppers, scales, and a few beetles also serve as vectors for certain viruses. Some viruses may persist for weeks or months and even duplicate themselves in their insect vectors; others are carried for less than an hour.

Detailed explanation-2: -Infectious plant diseases are mainly caused by pathogenic organisms such as fungi, bacteria, viruses, protozoa, as well as insects and parasitic plants [1].

Detailed explanation-3: -From the explanation, the correct answer is A which is red rot of sugarcane which is caused by fungus and not virus.