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A diverse set of parasites and pathogens affects productivity and survival of Apis mellifera honeybees. In beekeeping, traditional control by antibiotics and molecules of synthesis has caused problems with contamination and resistant pathogens. In this research, different Laurus nobilis extracts are tested against the main honeybee pests through an integrated point of view. In vivo effects on bee survival are also evaluated. The ethanol extract showed minimal inhibitory concentration (MIC) values of 208 to 416 μg/mL, having the best antimicrobial effect on Paenibacillus larvae among all substances tested. Similarly, this leaf extract showed a significant antiparasitic activity on Varroa destructor, killing 50 % of mites 24 h after a 30-s exposure, and on Nosema ceranae, inhibiting the spore development in the midgut of adult bees ingesting 1 × 10(4) μg/mL of extract solution. Both ethanol extract and volatile extracts (essential oil, hydrolate, and its main component) did not cause lethal effects on adult honeybees. Thus, the absence of topical and oral toxicity of the ethanol extract on bees and the strong antimicrobial, microsporicidal, and miticidal effects registered in this study place this laurel extract as a promising integrated treatment of bee diseases and stimulates the search for other bioactive phytochemicals from plants.

Aragunde, Constanza Brasesco, Martín Eguaras, et al.. Nitric oxide participates at the first steps of Apis mellifera cellular immune activation in response to non-self recognition.Abstract -The honey bee Apis mellifera (Hymenoptera) is being affected by many diseases. The elimination of organisms in the insect hemocoel requires hemocytes recognition and response to the invader. After recognizing a surface as "foreign," hemocytes "spread." Spreading on glass surfaces by insect hemocytes is used as a measure of immune activation. Nitric oxide (NO) is a signaling and immune effector molecule in response to microbial infection that has been proposed as a key molecule in invertebrate immunity. The participation of NO in the hemocytic response of A. mellifera upon recognition of non-self is herein analyzed. Glass-adherent hemocytes produce large amounts of NO. Treatment with NO donor sodium nitroprusside enhanced hemocyte spreading, while NO scavenger carboxyPTIO reduced hemocyte immune activation. These results are indicative of NO participation at the beginning of A. mellifera immune response to non-self. Apis mellifera / immunity / nitric oxideCorresponding author: P. Negri,