Hemipteran vectors of stylet-borne plant viruses: Aphids lead the charge

Insect vectors play a key role in the transmission of plant viruses, acting as major drivers of crop losses worldwide. Noncirculative plant viruses rely on brief and transient interactions with their insect vectors for successful transmission. Here, we focused on aphids (Aphidoidea), whiteflies (Aleyrodoidea), and mealybugs (Coccoidea), hemipterans of the suborder Sternorrhyncha, known for transmitting 95% of viruses in a noncirculative mode. Based on the current knowledge, we compared specific morphological and behavioral traits related to their stylets, the cuticular needle-like structures. This comparison shed some light on the leading role of aphids as vectors, owing to their highly specialized mouthparts and unique intracellular probing behavior. The review also discusses known key molecular interactions at the virus-stylet interface. Comparing these features across the 3 hemipteran superfamilies underscores how specific behavioral and anatomical traits set aphids apart, enabling their remarkable capacity to transmit stylet-borne, noncirculative viruses.