To select and establish floral biomarkers of the botanical origin of Diplotaxis tenuifolia honeys, the flavonoids and glucosinolates present in bee-deposited nectar collected from hive combs (unripe honey) and mature honey from the same hives fron which the unripe honey samples were collected were analyzed by LC-UV-PAD-ESI-MS n . Glycosidic conjugates of the flavonols quercetin, kaempferol, and isorhamnetin were detected and characterized in unripe honey. D. tenuifolia mature honeys contained the aglycones kaempferol, quercetin, and isorhamnetin. The differences between the phenolic profiles of mature honey and freshly deposited honey could be due to hydrolytic enzymatic activities. Aliphatic and indole glucososinolates were analyzed in unripe and mature honeys, this being the first report of the detection and characterization of glucosinolates as honey constituents. Moreover, these honey samples contained different amounts of propolis-derived flavonoid aglycones (1765-3171 μg/ 100 g) and hydroxycinnamic acid derivatives (29-1514 μg/100 g). Propolis flavonoids were already present in the freshly deposited nectar, showing that the incorporation of these compounds to honey occurs at the early steps of honey production. The flavonoids quercetin, kaempferol, and isorhamnetin and the glucosinolates detected in the samples could be used as complementary biomarkers for the determination of the floral origin of Argentinean Diplotaxis honeys.

-An organic product based on oxalic acid was evaluated for use in Varroa control under spring/summer climatic conditions in Argentina. The formulation consists of four strips made of cellulose impregnated with a solution based on oxalid acid. Forty-eight beehives were used to assess the product efficacy. Residues of the product were also tested in honey, bees, and wax. Each trial had respective control groups without oxalic treatment. At the beginning of the experiment, four strips of the formulation were applied to the colonies belonging to the treated group. Falling mites were counted after 7, 14, 21, 28, 35, and 42 days. After the last count, the strips were removed and colonies received two flumethrin strips for 45 days. Falling mites were counted throughout this period. Average efficacy of the organic product was 93.1 % with low variability. This product is an organic treatment designed for Varroa control during brood presence and represents a good alternative to the synthetic treatments.Varroa destructor / control / oxalic acid / bee brood / Argentina

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Introducción y objetivos: Una asignación diferencial de recursos entre la función de atracción, recompensa y sexual ha sido observada en capítulos de especies derivadas de Asteraceae. Los capítulos heterógamos están compuestos por flores pistiladas, estaminadas o estériles y perfectas, con lo cual las funciones sexual y de recompensa son realizadas por diferentes tipos de flores y en distintos momentos. Esta distribución espacial y temporal de las recompensas dentro del capítulo no es tan clara en especies con capítulos homógamos, donde todas las flores son perfectas y producen polen y néctar. Aquí evaluamos la distribución espacial y temporal de las recompensas florales en los capítulos homógamos de Hyalis argentea. M&M: Comparamos la fenología floral, el número de granos de polen y la concentración y volumen de néctar entre las flores marginales y centrales, y registramos el comportamiento de forrajeo de los visitantes florales. Resultados: Los capítulos tienen un patrón de floración centrípeto y también alterno y son visitados por abejas, hormigas, mariposas, polillas, escarabajos y trips, siendo Apis mellifera su principal polinizador. No encontramos un patrón temporal en la oferta de recompensas dentro de los capítulos, pero sí un patrón espacial en el volumen de néctar que aumenta desde las flores marginales hacia las del centro del capítulo. Conclusiones: Dicha variabilidad espacial en la cantidad de néctar podría afectar el comportamiento de forrajeo de los polinizadores y así aumentar las probabilidades de polinización cruzada, mejorando la reproducción sexual de esta especie autoincompatible.