A Bacillus spp. strain isolated from a honey sample in Morillos (Salta, Argentina) was phylogenetically characterized as B. subtilis subsp. subtilis Mori2. The strain was administered to bee colonies as a monoculture in one litre of sugarcane syrup (125 g/L) at a final concentration of 10(5) spores/mL to evaluate the bee colony performance. The treated colony was monitored, and any changes were compared with the control hives. All conditions were identical (weather, nourishment and supervision), except for the Bacillus spore supplement. The new nourishment, which was administered monthly from May to December 2010, was accepted by the bees and consumed within ca. 24-48 h. Photograph records and statistic analyses revealed significant differences in the open and operculated brood areas between the treated and control groups. The status of the colony improved after the second administration of the Bacillus spores until the end of the experiment. A higher number of bees were counted in the treated groups (26% more than the control) with respect to the initial number. Furthermore, at the time of harvest, honey storage in the treated hives was 17% higher than in the control hives. In addition, spore counts of both Nosema sp. and Varroa sp. foretica in treated hives were lower than in the control hives. These results with experimental hives would indicate that B. subtilis subsp. subtilis Mori2 favoured the performance of bees; firstly, because the micro-organism stimulated the queen's egg laying, translating into a higher number of bees and consequently more honey. Secondly, because it reduced the prevalence of two important bee diseases worldwide: nosemosis and varroosis.

Lactobacillus johnsonii CRL1647, isolated from the intestinal tract of a worker-bee in Salta, Argentina, was delivered to Apis mellifera L. honey bee colonies according to two different administration schedules: 1×10(5) cfu/ml every 15 days (2011) or monthly (2012). The effect of each treatment on the bee-colony performance was monitored by measuring honey production, and the prevalence of varroasis and nosemosis. Worker bees from each assay were randomly captured 3 days after administration and assayed for the following intestinal culturable and defined bacterial populations: total aerobic microorganisms, Bacillus spp. spores, Lactobacillus spp., Enterococcus spp. and enterobacteria. Interestingly, both treatments generated a similar increase in honey production in treated colonies compared to controls: 36.8% (every 15 days) and 36.3% (monthly). Nosema index always exhibited a reduction when lactobacilli were administered; in turn, Varroa incidence was lower when the lactobacilli were administered once a month. Moreover, the administration of L. johnsonii CRL1647 every 15 days produced an increase in the total number of aerobic microorganisms and in bacteria belonging to the genera Lactobacillus and Enterococcus; at the same time, a decrease was observed in the number of total spores at the end of the treatment. The number of enterobacteria was constant and remained below that of control hives at the end of the assay. On the other hand, the delivery of lactobacilli once a month only showed an increase in the number of bacteria belonging to the genus Lactobacillus; meanwhile, viable counts of the remaining microorganisms assayed were reduced. Even though it seems that both treatments were similar, those bee colonies that received L. johnsonii CRL1647 every 15 days became so strong that they swarmed.

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The main objective of this study was to determine the impact of Lactobacillus salivarius A3iob, a honey bee gut-associated strain (GenBank code access KX198010), on honey yield. Independent assays were conducted from May to September 2014 and 2015, in three commercial apiaries: Tilquiza, El Carmen and Yala, all located in north-western Argentina. Local Apis mellifera L. bees were kept in standard Langstroth hives; treated hives were fed once a month with 1×10 cfu/ml viable Lactobacillus cells, administered to the bees through a Doolittle-type feeder in 125 g/l sucrose syrup. Control hives were only given the syrup mixed with MRS sterile broth. The main honey harvest was done in December in all groups and we found that there was an overall increase in honey yield from the treated hives. In 2014, all treated hives produced between 2.3 to 6.5 times more honey than the controls. However, in 2015, higher honey average yields in the treated hives at El Carmen and Yala were obtained, yet not at Tilquiza, because of a slight mishap. They experienced the swarming of several bee colonies due to a higher number of bees without appropriate management, which caused the control group to yield more honey compared to the hives fed with Lactobacillus. Interestingly, at El Carmen, two honey harvests were recorded: one in winter and another in summer (July and December 2015, respectively). This unexpected result arose from the particular flora of the region, mainly Tithonia tubaeformis, which blooms in winter. L. salivarius A3iob cells prove to be a natural alternative that will positively impact the beekeepers' economy by providing a higher honey yield.

La presente investigación se realizó con el propósito de determinar la presencia de diferentes especies de hormigas en colmenas de Apis mellifera L., y describir la actividad observada mediante el relevamiento de apiarios ubicados en diversas localidades de Valles templados de la provincia de Jujuy. Se colectaron manualmente entre 10-20 individuos aproximadamente de diferentes especies de hormigas en estado adulto e inmaduro presentes en techos y entretapas de colmenas de abejas melíferas, como también de hormigueros ubicados en cercanías. Se conservaron en alcohol al 70%. La colecta se realizó en época seca y época húmeda. La identificación taxonómica se realizó mediante claves establecidas. Las hormigas identificadas fueron Camponotus substitutus, Camponotus mus, Acromyrmex hispidus, Linepithema humile, Crematogaster spp. (Subgénero Orthocrema) y Solenopsis spp. Cinco de estas especies no mostraron ser perjudiciales para las abejas, mientras que en colmenas moribundas por falta de alimento o reinas viejas se observó la intrusión de Solenopsis sp. Se puede concluir que las especies de hormigas identificadas no generaron daños económicos a los apicultores de estas colmenas. El presente trabajo podría ser el punto de partida para estudios relativos al manejo y control de hormigas presentes en colmenas de Apis mellifera L. Se debe continuar con el registro y estudio de estos himenópteros en otras áreas apícolas.