Biology and fundamental host range of the stem boring weevil, Apocnemidophorus piptzi, a new candidate for biological control of Brazilian peppertree, Schinus terebinthifolius

Brazilian peppertree (BP), Schinus terebinthifolius Raddi, was introduced into Florida, USA, from South America as an ornamental in the 1840s. It eventually escaped cultivation and has become an aggressive invader of disturbed and natural areas in peninsular Florida. BP is a serious threat to the state’s biodiversity, especially over large areas of the Everglades where it is displacing native vegetation. In the 1980s, this invasive weed was targeted for classical biological control because of the extent of the infestation and the absence of native congeners in the continental USA. In March 2006, a survey for new natural enemies of BP was conducted in the Itapúa Province in southeastern Paraguay. A weevil identified as Apocnemidophorus pipitzi (Faust) was collected from the plant at several locations. Adults resemble bird droppings and feed mainly on the upper surface of subterminal leaflets, where they produce a characteristic notching pattern. Adults were transported under permit to the Florida Biological Control Laboratory in Gainesville, FL, and a laboratory colony of the weevil was established in April 2007 by caging the adults on cut branches of BP supplemented with leaf bouquets. Females deposit eggs in the twigs and larvae feed under the bark where they damage the vascular cambium. A new generation of the weevil is produced in ~ ca. 3 months. Host range tests were conducted with 77 plant species in 39 families and 7 orders. The stem boring habit and results of laboratory risk assessment studies suggest the weevil A. pipitzi probably is a BP specialist.