Aphid

any of numerous tiny soft-bodied insects of the family Aphididae of worldwide distribution, that suck the sap from the stems and leaves of various plants, some developing wings when overcrowding occurs: an important pest of many fruit trees and vegetable crops.
Historical Examples

I once observed a young spider approaching an aphid, which was facing its enemy.
Cornell Nature-Study Leaflets Various

aphid (af’-id) The plant louse, of which there are a great many kinds.
The Insect Folk Margaret Warner Morley

Let the pupils see an aphid sucking the juice of a plant; this may be done by bringing in a twig infested by aphids.
Cornell Nature-Study Leaflets Various

He laughed in my face, and brought forward certain well-known facts in the reproduction of the aphid or cabbage-louse.
The Catholic World. Volume III; Numbers 1, 2, 3, 4, 5, 6. E. Rameur

The reproduction of the aphid constitutes one of the most interesting chapters in the history of the animal kingdom.
The Young Collector’s Handbook of Ants, Bees, Dragon-flies, Earwigs, Crickets, and Flies W. Harcourt Bath

The heterogamy of the allied Coccid is practically the same as that of the aphid.
The Works of Francis Maitland Balfour, Volume II (of 4) Francis Maitland Balfour

noun
any of the small homopterous insects of the family Aphididae, which feed by sucking the juices from plants Also called plant louse See also greenfly, blackfly
n.

1884, anglicized from Modern Latin aphides, plural of aphis, coined by Linnaeus (1758), though where he got it and why he applied it to the plant louse are mysteries. The theory favored by OED as “least improbable” is that it derives from the plural of Greek apheides “unsparing, lavishly bestowed,” in reference either to the “prodigious rate of production” of the insects or their voracity. They also are known as ant-cows.