Entomopathogenic nematodes (EPNs) are a promising alternative to integrated control in many fruit pests. Few studies were made on the relationship of Anastrepha fraterculus natural population with native EPNs population and other biotic and abiotic factors. The aim of this work was to verify the occurrence of endemic nematodes in an apple orchard, concerning environmental conditions and technical procedure, and access isolates virulence to A. fraterculus larvae. The experiment was conducted during a year taking monthly soil samples from an apple orchard, with and without fallen fruits just above the soil. Samples were baited with Tenebrium molitor and A. fraterculus larvae in laboratory. Canopy and fallen fruits were sampled to access the pest infestation. Seventy three EPN isolates were captured, in 23.2% soil samples, more with T. molitor than with A. fraterculus baits. From the 20 isolates tested against A. fraterculus, only five were pathogenic, and they were identified as Oscheius sp. The nematodes were captured during all seasons in a similar frequency. Soil and weather conditions, presence of fruit over the orchard soil, and A. fraterculus pupae in the fruits had no significant influence on the capture. As a conclusion, nematodes of the genera Oscheius are found in an apple orchard of Porto Amazonas constantly along the year, independently of fluctuations in A. fraterculus population, climate conditions and presence of fruit over the soil. Some of the isolates are pathogenic to A. fraterculus.
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The objective of this trial was to characterize the assemblage structure of fruit flies (Diptera: Tephritidae) by determining the diversity and faunal indices. Fruit flies were collected for ten years between 2003 and 2015 in six municipalities of the Metropolitan Region of Curitiba, Paraná. The orchards were divided into three crop protection strategies: organic, conventional, and integrated pest management. The characteristic of each community was determined using the Shannon-Wiener, Margalef, and Pielou's indexes. The frequency, constancy, and dominance indexes were also determined. Biological material was analyzed using the explanatory variables: site, crop, plant protection strategy, and susceptibility period. A total of 8,089 fruit flies were collected, of which 4,681 were females. The species Anastrepha daciformis Bezzi, A. dissimilis Stone, A. distincta Greene and A. pickeli Lima were recorded for the first time in Paraná State, the occurrence of three other species was recorded for the first time in the Metropolitan Region of Curitiba (A. montei Lima, A. obliqua Macquart, and A. sororcula Zucchi), in addition A. fraterculus (Wiedemann), A. grandis (Macquart) and Ceratitis capitata (Wiedemann). A. fraterculus accounted for 98.5% of the collected species. Only A. fraterculus and A. sororcula were found in fruits. Fruit flies occurred predominantly in peach trees cultivated under organic conditions. The Shannon index indicated that the municipality of Cerro Azul had the highest diversity and richness whereas apple orchards had the lowest diversity. Crops cultivated under organic conditions exhibited the highest diversity whereas those cultivated under conventional conditions had the highest evenness index. The largest specimens number was collected during the period of crop susceptibility.
The South American fruit fly, Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae), is an important pest in the subtropical region of Brazil. This insect has tritrophic relation between wild fruits and parasitoids and is associated with apple (Malus domestica Borkh.) orchards adjacent to the Atlantic Forest in Paraná. We thus investigated the degree of infestation of the fruit fly and natural parasitism in wild and cultivated fruits surrounding apple orchards. For this purpose, we collected fruits of Acca sellowiana (Berg.) Burret, Campomanesia xanthocarpa (Mart), Eugenia uniflora L., Eugenia pyriformis Cambessèdes, Psidium cattleianum Sabine, Psidium guajava (L.), Annona neosericea Rainer and Eriobotrya japonica (Thumb) in apple orchards adjacent to the Atlantic Forest located in Campo do Tenente, Lapa and Porto Amazonas counties. In total, we collected 18,289 fruits during four growing years. The occurrence of A. fraterculus depends on the susceptible period of apple fruits. A. sellowiana and P. cattleianum were considered primary fruit fly multipliers and P. guajava was secondary, all occurring after the apple harvest (IS period). The group of parasitoids with A. fraterculus was Aganaspis pelleranoi (Brèthes, 1924) (Hymenoptera: Figitidae), Opius bellus (Gahan, 1930), Doryctobracon areolatus (Szépligeti, 1911) and Doryctobracon brasiliensis (Szépligeti, 1911) (Hymenoptera: Braconidae) all of which are first records in the Atlantic Forest in Paraná. First record of O. bellus occurring in the State of Paraná, as well as, first record of the tritrophic association between host plant A. neosericea, parasitoids D. areolatus and O. bellus and fruit fly A. fraterculus. The host P. cattleianum stood out among the Myrtaceae species in regard to the high diversity of parasitoid species (81% of parasitoids). The total number of Figitidae species (76.5%) was higher than that of Braconidae species. The influence of climatic events in southern Brazil on wild fruit production should be further studied to understand the association of A. fraterculus with the tritrophic relationship.
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