Vol. 95, No. 2. March & April 1984 51 HOST PLANT RECORDS FOR NORTH AMERICAN RAGWEED FLIES (DIPTERA: TEPHRITIDAE) 1 B.A. Foote 2 ABSTRACT: Information is given on host plants and infestation rates for 7 of the 8 North American species of Euaresta. The host plants are either ragweeds of the genus Ambrosia or cockleburs of the genus Xanthium, 2 genera of the tribe Ambrosieae (Compositae). The genus Euaresta is a relatively small taxon within the family Tephritidae of the acalyptrate Diptera. It includes 8 species from America north of Mexico (Quisenberry, 1950; Foote, 1965), as well as several from south of the United States; however, virtually no host data are available for these latter species and some doubt exists as to whether they actually belong to the genus (R.H. Foote, in litt.). Relatively little is known of the life histories or larval feeding habits of the Nearctic species except that they seem to be associated either with cockleburs of the genus Xanthium or ragweeds of the genus Ambrosia (Compositae: Ambrosieae). Marlatt ( 1 89 1 ) discussed the natural history of E. aequalis(Loew), a seed predator of cocklebur (X. strumarium L.). Foote (1965) reported that larvae of E. bella(Loew) and E. festiva (Loew) attacked the seeds of common ragweed (A. artemisiifolia L.) and giant ragweed (A. trifida L.), respectively. He also listed host plants for selected species of Euaresta and discussed briefly the life cycles of E. bella and E. festiva. Batra (1979) described in considerable detail the courtship behavior and oviposition habits of these two species. Goeden and Ricker (1974a, 1974b, 1976) recorded host plants for E. bellula Snow and E. stigmatica Coquillett. Wasbauer ( 1972) listed hosts for 7 species of Euaresta. Because species of Ambrosia are prime sources of hayfever-causing pollen (Dickerson and Sweet 1 97 1 ) and are important weeds in agricultural regions (Danielson et al. 1965), various workers (e.g. Harris and Piper 1970) have suggested that seed predators such as the larvae of Euaresta spp. could be important biocontrol agents. The present paper gives information on the host plants and infestation rates for several of the Nearctic species of Euaresta. MATERIALS AND METHODS Unless otherwise indicated on Table 1 , all of the host plant records were obtained by the author. Collections of seeds obtained in the field were 'Received April 22, 1983. Accepted February 14. 1984. ^Department of Biological Sciences, Kent State University, Kent, OH 44242 ENT. NEWS 95(2) 51-54 March & April 1984
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