INVESTIGADORES
SOSA alejandro JoaquÍn
congresos y reuniones científicas
Título:
Combining the evaluation of local-scale factors with bio-ecological variables for pest studies in wetland rice production.
Autor/es:
DANIELA FUENTES-RODRÍGUEZ; PAULA GERVAZONI; ALEJANDRO JOAQUÍN SOSA; C. FRANCESCHINI
Lugar:
Beijing
Reunión:
Congreso; The 3rd International Conference on Advances in Civil and Ecological Engineering Research (ACEER 2021); 2021
Resumen:
The study of factors related to landscape in rice pest studies is important to visualizeecological patterns of these species within the wetland agroecosystem, and help to improveunderstandings about these patterns. Through several studies that have been conducted in Argentina,we detected the influence of a few local scale factors that would explain the occurrence of certainevents in pest populations related to wetland rice production, such as the selection of overwintering 27sites, the impact of potential biological controllers, among others. The aim of this study is to highlightthe value of the research on local scale factors as a tool for pest management in rice paddies, taking asa case study two of the most important pests in South American paddies: the stink bugs Oebaluspoecilus and Tibraca limbativentris (Hemiptera: Pentatomidae). Considering both quantitatively andcategorically, we selected certain variables inherent to pest populations (abundance, trophicguild/niche) and their natural enemies (entomopathogenic fungi - "EF") to study differentcharacteristics (factors) of the local landscape and their interrelationships (varieties of rice, height of rice plants, height of alternate winter hosts). To evaluate pest abundance, samplings were carried out during the cultivation season (spring-summer). To measure the incidence of EF, manually collected adults were kept alive under experimental conditions to detect mycelial development. As results, regarding to the local characteristics of the landscape, two varieties of rice were recorded in the target rice fields, a tall variety and a short variety. There, 2711 adult individuals of stink bug pests were obtained, where O. poecilus was the most abundant with 83.54% of the total of individuals collected. Regarding the incidence of EF, 25.19% of the 659 stink bugs examined were infected. This incidence was significantly higher in T. limbativentris (approx. 90% of the total incidence), whose trophic guild is related to feeding on the plant stem (stem-feeding) and was also significantly higher in the shorter rice variety, with the 43.94% of the total incidence registered. Thereby, the incidence of EF in the evaluated pests was related to the architecture of the plants (height), as well to their trophic guild (stemfeeding vs. seed-feeding), being higher in stem-feeding species and in the shorter rice variety. Likewise, when comparing the obtained data during the cultivation season for T. limbativentris with landscape local factors previously evaluated in each target site during winter (height of its winter host plants), a positive correlation was obtained between the height of the different rice cultivars used during the spring-summer and the height of the host plants selected by T. limbativentris near these plots during winter. This shows that the height of the rice cultivar could be a local factor related to the local selection of winter hosts by T. limbativentris and to the incidence of EF for both pest species. This information will be useful to locally predict overwintering areas of T. limbativentris and remark its importance in considering the rice cultivar and the trophic guild/niche of each pest group when selecting efficient biological controllers to implement integrated management strategies of pests in each particular wetland rice agroecosystem.