Host specificity of Bangasternus orientalis Capiomont (Coleoptera : Curculionidae) introduced into the United States for biological control of yellowstarthistle (Centaurea solstitialis L., Asteraceae : Carduae)
G. Campobasso et al., Host specificity of Bangasternus orientalis Capiomont (Coleoptera : Curculionidae) introduced into the United States for biological control of yellowstarthistle (Centaurea solstitialis L., Asteraceae : Carduae), ENV ENTOMOL, 27(6), 1998, pp. 1525-1530
The weevil Bangasternus orientalis Capiomont was selected as a candidate fo
r the biological control of Centaurea solstitialis L. (yellow starthistle)
in the United States. Its potential host range was studied during 1982, 198
3, and 1984 in Rome, Italy, using populations collected from C. solstitiali
s in Thermi near Thessaloniki and Kozani in northern Greece. Adults laid eg
gs only on members of the genus Centaurea and the thistle Onopordum acanthi
um; eggs laid on O. acanthium hatched but Ist instars died before entering
buds. There was no significant difference in the number of eggs laid on var
ious U.S. and Italian strains of C. solstitialis included in the tests. Egg
s were not deposited on plant species of economic importance such as Cynara
scolymus, Helianthus annuus, Carthamus tinctorius, and Lactuca sativa. Lar
vae completed their larval development only on C. solstitialis from Greece
and on U. S. and Italian populations of C. solstitialis among the 60 plant
species, varieties, and strains (in 7 families) tested. This restricted hos
t range suggested introduction of this weevil as a biological control agent
against yellow starthistle in the United States. Releases of B. orientalis
were made in California, Washington, Idaho, and Oregon in 1985 and it beca
me established in all states in 1989.