Most aphid species are pretty hard to recognize just by looking at them without a microscope, DNA analysis, and extensive expertise. With more research many species will be discovered to actually be groups of identicle sibling species. Most aphids resemble simple greenish blobs! Wire Lettuce Aphids tend to occur only on wire lettuce species. Many species are thus host specific having evolved for millions of years tracking the chemical and physical barriers. Aphids tend to be mostly immobile when feeding because their delicate piercing mouth parts are inserted deep in the plant tissue. Uroleucon when feeding face head down. It disturbed their meager defense is to kick with their hind legs. Many predators take advantage of these not quite defenseless insects.

Aphids prefer to feed on lush new growth. As long as the host plant remains fresh and green the aphids will be wingless even as adults. But when the plant begins to dry with oncoming drought conditions the aphids will molt again revealing two pairs gossamer wings allowing them to fly off to a better area. High winds can carry them a considerable distance.