The Phytophagous Insect Fauna of the Ragweed, Ambrosia acanthicarpa , in Southern California 1

Abstract

Phytophagous insects representing 7 orders, 31 families, and 87 species are reported as comprising the insect fauna of Ambrosia acanthicarpa Hooker (Compositae) in southern California. Most insects found attacking this native ragweed were euryphagous, ectophagous, sap– and foliage-feeding species. About a third reproduced on this plant. Fourteen (19%) of the 73 identified associates were stenophagous species, their host plants apparently confined to the tribe Heliantheae. About a third of these identified associates were minor or major pests of cultivars.