More than 5,000 aphid species are known, many of which are pests that result in significant economic losses in a wide range of crops worldwide. Aphids possess several types of symbiotic microorganisms, particularly symbiotic bacteria and viruses. The mutualistic relationship with viruses is an aspect of plant disease has not been well explored.
Researchers at Umeå University and Wageningen University have discovered how plants can defend themselves against aphids. They recorded aphid behaviour on video and identified a plant protein that keeps aphids from feeding.