Which insects are commonly associated with the spread of viruses?

Aphids and leafhoppers are well-known vectors for the transmission of various plant viruses. These insects feed on plant sap and, during their feeding activities, can acquire viruses from infected plants. Once they have ingested the virus, they can transmit it to healthy plants, facilitating the spread of the infection. This ability to spread pathogens makes aphids and leafhoppers significant pests in agricultural settings, as they can lead to substantial crop losses due to viral infections.

In contrast, the other options do not share the same role as vectors for plant viruses. Caterpillars are primarily herbivores and feed on leaves, but they do not typically spread viruses. Beetles and moths may cause damage to plants but are not commonly associated with viral transmission. Ants and spiders are not known to be involved in the spread of viruses because their feeding behaviors do not facilitate the transmission that occurs with sap-sucking insects like aphids and leafhoppers.