PROC. ENTOMOL. SOC. WASH. 94(1), 1992, pp. 107-118 ANALYSIS OF KNOWN AND NEW HOST RECORDS FOR TRUPANEA FROM CALIFORNIA (DIPTERA: TEPHRITIDAE) Richard D. Goeden Department of Entomology, University of California, Riverside, California 92521. Abstract. — One hundred twenty-four, new rearing records are reported for eight of the 16 known species of Trupanea occurring in California. The host relations of all 16 species are assessed, including T. texana Malloch newly reported from California, for which hosts are unknown; one species for which only the host genus is known; four other monophagous species; three oligophagous species (one host tribe); one nearly oligophagous species; and six generalist species, all restricted to Asteraceae. Trupanea signata Foote is reported for the first time as a monophagous, obligate stem-gall former on Gnaphalium luteo-album L. One other monophagous species, as known to date, probably also is an obligate gall former; whereas, another is a facultative gall former. All other 1 1 species are ovule and soft achene feeders in flower heads, including Trupanea arizonensis Malloch, newly re-ported as monophagous on Trixis californica Kellogg. The host tribes are tabulated and the number of host genera and species within them are enumerated for each fly species. The six generalist species have been reared from at least five tribes each. This dispersed pattern of hosts among tribes is discussed in terms of procedures for determining the host specificities of Tephritidae as candidate agents for biological control of weeds. Two plant species, Brickellia oblongifolia Nuttall in the tribe Eupatorieae and Haplopappus squar-rosus Hooker and Arnott in the tribe Astereae, are attacked by all six generalists. The Astereae, Cichorieae, Helenieae, Heliantheae, and Senecioneae contain the most host-plant genera and species recorded, and also are the largest of the 1 2 tribes of Asteraceae in southern California. Key Words: Insecta, Trupanea, Tephritidae, Asteraceae, flower head-feeders, host spec-ificities, monophagy, oligophagy, gall-formers, biological control, evolution, resource utilization, speciation Six years ago I reported many new records for Trupanea (Diptera: Tephritidae) reared from flower heads of Asteraceae in southern California (Goeden 1985). This paper re-ports additional rearing records acquired since mid-1984 from both northern and southern California for this common and widespread genus of nonfrugivorous fruit flies (Foote and Blanc 1963). Materials and Methods Materials and methods used were de-scribed by Goeden (1985). My earlier em-phasis on sampling in southern California was changed during 1985-1990 to include collecting trips of 3-to 5-days duration to northern California, as floristically and geo-graphically defined by Munz (1974). This expanded collecting effort in northern Cal-ifornia allowed sampling of plant species and Tephritidae not present, or only of lim-ited occurrence, in southern California (Munz and Keck 1959, Foote and Blanc 1963, Munz 1974). Voucher specimens of tephritids reside in my research collection; pressed voucher specimens of uncommon
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