Laboratory biology and impact of a stem-boring weevil Apocnemidophorus pipitzi (Coleoptera: Curculionidae) on Schinus terebinthifolia

ABSTRACT

Brazilian peppertree, Schinus terebinthifolia Raddi (Anacardiaceae), was introduced into Florida, USA, from South America as an ornamental plant in the late 19th and early 20th centuries. It eventually escaped cultivation and is a serious threat to the state’s biodiversity. In the 1980s, this invasive weed was targeted for classical biocontrol. Surveys for natural enemies of Brazilian peppertree conducted in the native range resulted in the discovery of several candidate biocontrol agents. A stem-boring weevil identified as Apocnemidophorus pipitzi (Faust) was collected in Paraguay and transported under permit to Florida, USA. A laboratory colony of A. pipitzi was established in April 2007 by caging adults on cut branches of Brazilian peppertree supplemented with leaf bouquets. Adults are defoliators that feed mainly on the upper surface of subterminal leaflets. Females deposit eggs singly inside the stems and larvae feed under the bark where they damage the vascular cambium. There are five instars, pupation occurs inside the stem and a new generation is produced in 3–4 months. Growth of potted plants with and without exposure to weevil herbivory was compared over an 11-month period. Feeding damage by adults and larvae significantly increased leaf abscission and reduced leaf and root biomass accumulation.

KEYWORDS:

• Invasive plants
• weevil biology
• herbivory
• weed biocontrol

Acknowledgements

We thank Kenia Duran Aguirre, Michael Arvin, Brendan Bennett, Alissa Berro, Paulo Bertolla, Devon Donahue, Shweta Sharma, Flavia Vaduva, and Tanya Stevens for assistance with maintenance of plant and insect colonies and data collection, Jane Medley for providing the figures, and Mihai Giurcanu for help with statistical analyses. We also thank Lyle Buss for the images of the different life stages of A. pipitzi, and Mary Wilson for the MRI scan of the Brazilian peppertree stem cross section.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported in part by the Florida Department of Environmental Protection [grant number 13926020]; and the Florida Industrial and Phosphate Research Institute [grant number 107428].