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Aphids cause great damage to cruciferous crops—broccoli, brussels sprouts, cabbage, cauliflower, kale, mustard, radishes, turnips, and others. These insects weaken, stunt, and sometimes even kill the plants by sucking the juice. They may make cabbage, brussels sprouts, cauliflower, and broccoli wholly unfit to market, for it is difficult or impossible to remove them from the heads of such plants. On seed farms, they may completely destroy the plants before harvest by infesting the seedstalks. They cause even greater losses by transmitting plant viruses, which may destroy the plants over considerable areas.

Three aphid species that breed on these plants are responsible for most of the damage in California. These are the cabbage aphid, Brevicoryne brassicae (Linnaeus); the turnip or false cabbage aphid, Rhopalosiphum pseudobrassicae (Davis); and the green peach aphid, Myzus persicae (Sulzer). All three species have become world wide in distribution and are to be found generally throughout the ranges of the host plants. This paper assembles the salient facts on their synonymy, characteristics, life histories, distribution, and host plants, as a basis for studies on their transmission of viruses and on their control.

The Cabbage Aphid

Brevicoryne brassicae (Linnaeus) (Van der Goot, 1915), (1918)3, 4

Aphis brassicae(Linnaeus (1746), (1758)5

Aphis raphani(Schrank (1801))6

Aphis insatidis(Boyer de Fonscolombe (1841))7

Aphis floris-rapae(Curtis (1860), p. 69-83)8

The cabbage aphid, Brevicoryne brassicae (Linnaeus) is usually more abundant on cruciferous crops than any other aphid and is therefore more injurious.

The cabbage aphid can be distinguished from other aphids by the large closely crowded colonies (fig. 1), the white waxy powdery covering over the bodies of the alate and apterous individuals, and the cruciferous host plant.