Phytophagous Insect Fauna of the Desert Shrub Hymenoclea salsola in Southern California

Abstract

Phytophagous insects representing 8 orders, 33 families, 64 genera, and 80 species are reported as comprising the insect fauna of the native, xerophytic shrub Hymenoclea salsola Torrey & Gray (Compositae) in southern California. Most insects attacking this plant are polyphagous, ectophagous, sap- and foliage-feeding species. At least 9 of 16 associated monophages are new or probably new species. More than half of the 75 identified species also occur on other Ambrosiinae (i.e., Ambrosia and Xanthium spp.) in southern California. Half were found at 4 or fewer of 55 sample sites, and most of these rare species were restricted to only part of the total geographic range of H. salsola in California. The most constant associates were two undescribed monophagous gall midges. Most species were represented by few individuals in collections at each survey site.