Invasive teasels (Dipsacus spp., Dipsacaceae) are widespread in the USA, being present in 43 states and listed as noxious in five. The cimbicid sawfly Abia sericea (Linné, 1767) is under evaluation as a potential agent for classical biological control of teasels. The host range, biology, and life history of this insect were studied under laboratory conditions and in common garden experiments from 2006–2010 at the Agricultural University of Plovdiv, Bulgaria in order to determine if this biocontrol candidate justified the expense of further testing under quarantine conditions in the USA. In the laboratory, potted plants from twelve plant species belonging to seven families were tested in choice tests of oviposition and feeding. Eggs were laid only on D. laciniatus and D. fullonum plants with only one exception, on Valeriana officinalis, although the larvae that hatched from the latter did not feed on that plant. Larval feeding was observed only on D. laciniatus, Knautia arvensis, and Scabiosa ochroleuca, all in the family Dipsacaceae, which has no species native to the New World nor any of economic importance. In common garden tests into which adults and third- and fourth-instar larvae were released in separate tests, eggs were laid and larvae fed only on D. laciniatus. The results of these experiments indicate that A. sericea has a narrow host range, most likely limited to Dipsacus species, and a few other Dipsacaceae and that further pre-release studies in a US quarantine are warranted.