Susceptibility of sweet orange (citrus sinensis l. osbeck) and tahitiacid lime (citrus latifolia yu. tanaka) to fruit fly infestation (diptera: tephritidae) under controlled and field conditions

Within the scope of international trade in fresh fruits, Brazil stands out as an exporter of Tahiti acid lime (LAT) to the European Union. In Brazil, the phytosanitary certification process falls under the responsibility of the Ministry of Agriculture and Livestock (MAPA) and the State Agricultural Defense Agencies. In order to meet the requirements of European Community Directives 523/2019 and 2021/2285/EC, this study presents field data (adult monitoring) and laboratory data (forced infestation). Over 45 weeks in 2020, adults were collected on four farms—Aros Agrícola, Rebouças, AgropecuáriaGavião, and ITACITRUS—using McPhail traps and food attractants. Females were identified by a specialist taxonomist. The MAD index (flies/trap/day) expressed population density, and the Faunistic Index expressed species diversity of fruit flies (FF) on each farm. Forced infestation was carried out at the Entomology Laboratory of Embrapa Cassava and Fruits (2023/2024), using Anastrepha obliqua, in three sweet orange varieties— ‘Valencia’, ‘Natal’, and ‘Pera’—and Tahiti acid lime, with 10 replicates per variety, including a positive control with mango and an absolute negative control (fruit only). The MAD index for the Rebouças, Aros Agrícola, AgropecuáriaGavião, and ITACITRUS farms was 7.44, 6.16, 2.28, and 0.69, respectively. The prevalent species were A. fraterculus, A. obliqua, A. pseudoparallela, A. distincta, A. consobrina, A. sororcula, A. dissimilis, A. quiinae, A. zenildae, and Anastrepha sp. In the faunistic analysis, A. fraterculus was the dominant species (52.67%), followed by A. obliqua (22.32%) and A. pseudoparallela (9.82%). Regarding frequency, species were classified as Constant (A. fraterculus), Common (A. obliqua, A. pseudoparallela, A. distincta), and the remaining species as Rare. Symptoms of punctures and/or oviposition on the ‘Pera’ variety (28.8%) were higher than on the ‘Valencia’, Natal’, and LAT varieties, with 11.9%, 8.3%, and 7.1%, respectively. No fruit showed larval development or subsequent adult emergence. The positive control (mango) showed symptoms in 96.7% of the fruits, with 349 pupae and 100% pupal viability. The genus Anastrepha was prevalent in the evaluated areas. The MAD index indicated low population density of fruit flies. Considering MAD values below 1.0, only the ITACITRUS farm would be able to export Tahiti acid lime fruits without phytosanitary treatments. The population characterization of fruit flies in orchards, as well as the assessment of host preference, enables official agencies to develop pest control strategies and to ensure phytosanitary certification at origin, an instrument that enables citrus exportation, thereby maintaining economic agreements within the Southern Common Market (Mercosur), generating foreign exchange for Brazil and ensuring thousands of jobs in the service sector linked to citrus production in Bahia.