Synonyms and other taxonomic changes
Chamaesphecia empiformis (Esper, 1783)
Sphinx empiformis Esper, 1783
"Repeated releases of Chamaesphecia empiformis in the 1970s as well as another root-boring insect, C. tenthrediniformis (Denis and Schiffermüller), on North American leafy spurge, did not result in establishment. It later was determined that these Chamaesphecia species are host specific to the European plants E. esulae and E. cyparissias" (Gassmann and Schroder, 1995).
Gassmann, A. and D. Schroeder. 1995. The search for effective biological control agents in Europe: history and lessons from leafy spurge (Euphorbia esulae L.) and cypress spurge (Euphorbia cyparissias L.). Biological Control
Harris, P. 1984. Euphorbia esula-virgata complex, Leafy Spurge and E. cyparissias L., Cypress Spurge (Euphorbiaceae).
in J.S. Kelleher & M.A. Hulme, 1984. Biological Control Programmes Against Insects and Weeds in Canada 1969-1980
. p. 163-165.
Nechols, J.R. "Leafy Spurge." Biological Control in the Western United States: Accomplishments and Benefits of Regional Research Project W-84, 1964-1989
. Oakland, CA: U of California, Division of Agriculture and Natural Resources, 1996. 291-292