Grupo de investigación AGR-218
Unidad de Apicultura
Archivos de Zootécnia 70: 186-190 (2021)
Peso al nacimiento de abejas reina de la raza Apis mellifera iberiensis
En el mundo apícola se acepta que la producción de una determinada colonia de abejas se encuentra directamente relacionada con la calidad de la reina. De todas las posibles variables relacionadas con dicha calidad, el peso al nacimiento se considera una de las más útiles. En nuestro trabajo hemos estudiado el efecto de la colonia criadora de la subespecie local de abejas (Apis melífera iberiensis Engel), sobre el peso al nacimiento de las nuevas reinas, y de las celdillas en las que fueron criadas. Para realizar la cría hemos utilizado el método Doolittle; este procedimiento se encuentra ampliamente difundido y es empleado de forma habitual por los productores. Entre los meses de marzo y mayo de 2019 criamos 140 reinas, realizando ocho ciclos de cría y utilizado cuatro colmenas criadoras diferentes. El peso medio de las reinas al nacimiento fue de 194 ± 26 mg (x ± SD), y el de las celdillas de cría 604 ± 125 (x± SD). Los resultados obtenidos no mostraron diferencias significativas entre las colmenas criadoras, para la variable peso de las reinas al nacimiento, pero si para la variable peso de las celdillas reales.
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Chemosphere 262: 127735 (2021)
A three-year large scale study on the risk of honey bee colony exposure to blooming sunflowers grown from seeds treated with thiamethoxam and clothianidin neonicotinoids
Despite the restriction of the use of neonicotinoids in the EU, including thiamethoxam and clothianidin, the debate over their risk on honey bees has not been fully settled. This study presents results of a three-year study working with 180 honey bee colonies in ten replicates. Colonies were sorted into three treatments (60 colonies per treatment) exposed to sunflower blooms grown from seeds treated with thiamethoxam, clothianidin and a non-treated control. Each colony was assessed at six moments: one before to exposition to sunflower, two during the exposition (short-time risk), two after exposition (medium-time risk) and one after wintering (long-time risk). The health and development of the colonies were assessed by monitoring adult bee population, brood development, status of the queen, food reserves and survival. No significant difference among treatments when raw data was considered. However, when evolution from initial status of the colony was evaluated, a significant difference was observed from the first week of exposure to sunflower blooms. In this period, the number of adult bees and the amount of brood were slightly lower in the bee hives exposed to neonicotinoids, although such differences disappeared in subsequent evaluations. The concentration of residues in samples of beebread and adult bees was at the level of ng·g -1 . Magnitude of the effect of the treatment factor on the variability of colony health and development related parameters was low. The most important factor was the hive, followed by the replicate and year, and to a lesser extent the initial strength of the colonies.
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Sustainability 12: 6431 (2020)
Regulation of Microclimatic Conditions inside Native Beehives and Its Relationship with Climate in Southern Spain
In this study, the Wbee Sensor System was used to record data from 10 Iberian beehives for two years in southern Spain. These data were used to identify potential conditioning climatic factors of the internal regulatory behavior of the hive and its weight. Categorical principal components analysis (CATPCA) was used to determine the minimum number of those factors able to capture the maximum percentage of variability in the data recorded. Then, categorical regression (CATREG) was used to select the factors that were linearly related to hive internal humidity, temperature and weight to issue predictive regression equations in Iberian bees. Average relative humidity values of 51.7% ± 10.4 and 54.2% ± 11.7 were reported for humidity in the brood nest and in the food area, while average temperatures were 34.3 °C ± 1.5 in the brood nest and 29.9 °C ± 5.8 in the food area. Average beehive weight was 38.2 kg ± 13.6. Some of our data, especially those related to humidity, contrast with previously published results for other studies about bees from Central and northern Europe. Conclusively, certain combinations of climatic factors may condition within hive humidity, temperature and hive weight. Southern Iberian honeybees' brood nest humidity regulatory capacity could be lower than brood nest thermoregulatory capacity, maintaining values close to 34 °C, even in dry conditions.
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