Laboratory and field assessments of lethal and sublethal toxicities of acetogenin-based bioinsecticides against Zaprionus indianus (Diptera: Drosophilidae)

Fernanda C.S. Geisler1, Liliane N. Martins1, Rute C.B. Treptow1, Cléber A. Baronio1, Paloma Stupp1, Leandro P. Ribeiro2, Flávio R.M. Garcia1, and Daniel Bernardi1*
Neotropical Annonaceae-derived bioinsecticides have shown promising control of insect pest species. In order to develop an alternative tool for control Zaprionus indianus (Gupta, 1970), an important invasive pest of Brazilian orchards, this study investigated the insecticidal activity of a formulation prepared from ethanolic seed extract of different Annona species (Annona mucosa Jacq., Annona muricata L., and Annona sylvatica A. St.-Hil.) at discriminatory concentration of 2000 mg L-1 in comparison with a limonoid-based bioinsecticide and a synthetic insecticide (spinetoram) as positive controls. In an ingestion and topical application bioassay, the formulation based on A. mucosa caused more than 95% mortality, which was equivalent to the mortality caused by the synthetic insecticide spinetoram. In a free-choice bioassay, A. mucosa (83%), bioinsecticide (88%) and synthetic insecticide (98%) produced a significant reduction in the number of eggs per fruit. In addition, formulations based on A. mucosa, A. sylvatica, A. muricata and bioinsecticide resulted in a 50% reduction in egg viability. In the field, A. mucosa and bioinsecticide negatively influenced the infestation by Z. indianus in figs, producing a significant reduction in the number of larvae per fruit (3.6 and 2.29 larvae per fruit, respectively) in relation to the control treatment (11 larvae per fruit). However, they were significantly inferior to the synthetic insecticide (0.71 larvae per fruit). Thus, A. mucosa, bioinsecticide and spinetoram have the potential to be used in the framework of Z. indianus management.
Keywords: Fig fly, Annonaceae, rolliniastatin-1, sustainable pest management.
1Universidade Federal de Pelotas, Pelotas, Rio Grande do Sul, 96010900, Brasil. *Corresponding author (dbernardi2004@yahoo.com.br). 2Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina, Chapecó, Santa Catarina, 89801-970, Brasil.