Field release of a prospective biological control agent of weeds, Ceratapion basicorne, to evaluate potential risk to a nontarget crop

► Ceratapion basicorne is a prospective biological control agent for yellow starthistle. ► The weevil can sometimes develop on safflower under laboratory conditions. ► We released the weevil in a field of safflower plants to measure risk of attack. ► None of over 1000 safflower plants were attacked by C. basicorne. ► The results indicate that this insect poses no significant risk to safflower.