About the aphid
Uroleucon sonchi is appropriately called the Large Sowthistle Aphid, as it is both large and found on plants in the genus Sonchus, or sowthistles. The individuals shown here are quite red, especially the juveniles, but they are often darker brown in color as well. Adults are very large, with long antennae and legs with darkened joints. Their size and morphology make their mouthparts quite easily visible compared to some of the other aphids. No winged morphs are pictured here as there were none in the colony at the time, but they do occur, especially when crowded. Most aphids in the genus Uroleucon are similarly sized and colored, and colonies are often easy to spot in the field. This species can be found both on stems and the undersides of leaves.