The biocontrol agent Lactiplantibacillus plantarum AMBP214 is dispersible to plants via bumblebees.

IMPORTANCE: Plant protection products are essential for ensuring food production, but their use poses a threat to human and environmental health, and their efficacy is decreasing due to the acquisition of resistance by pathogens. Stricter regulations and consumer demand for cleaner produce are driving the search for safer and more sustainable alternatives. Microbial biocontrol agents, such as microorganisms with antifungal activity, have emerged as a promising alternative management strategy, but their commercial use has been limited by poor establishment and spread on crops. This study presents a novel system to overcome these challenges. The biocontrol agent Lactiplantibacillus plantarum AMBP214 was spray-dried and successfully dispersed to strawberry flowers via bumblebees. This is the first report of combining spray-dried, non-spore-forming bacteria with pollinator-dispersal, which scored better than the state-of-the-art in terms of dispersal to the plant (CFU/flower), and resuscitation of the biocontrol agent. Therefore, this new entomovectoring system holds great promise for the use of biocontrol agents for disease management in agriculture.

Bee-Vectored Aureobasidium pullulans for Biological Control of Gray Mold in Strawberry.

Gray mold caused by Botrytis cinerea is a common postharvest disease in strawberries, reducing shelf life considerably. We investigated the potential of the yeast-like biocontrol fungus Aureobasidium pullulans (AP-SLU6) vectored by bumblebees (Bombus terrestris) in the Flying Doctors® system to inhibit the pathogen and increase the shelf life of harvested strawberries (cultivar Sonata). Using bumblebees as vectors of various biocontrol agents is becoming increasingly popular, but any potentially negative effects on bee performance have been understudied. Our results show that, over the 4-week period of the trial, the performance and activity of the bees were not negatively affected by A. pullulans. The bees successfully picked up the powder formulation; then, they carried and deposited it on the flowers. The vectoring of the biocontrol agent significantly reduced gray mold development on the harvested fruits by 45% and increased shelf life by 100% in comparison with control treatments. This suggests that the biocontrol fungus applied during flowering successfully reduced Botrytis infection and thus, effectively protected the fruits from gray mold. In addition, the bee-vectored application of the biocontrol agent was found to be significantly more effective than spray application because the latter may temporarily increase humidity around the flower, thereby creating a suitable environment for the pathogen to thrive. In summary, our study demonstrates that A. pullulans vectored by bumblebees can decrease gray mold infection and improve the shelf life of strawberries without adversely affecting the bees, thus providing a basis for the sustainable and efficient control of gray mold on strawberry.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

Different bees as vectors for entomovectoring with enhanced pollination and crop protection control: current practices, use cases and critical view on transport.

Honeybees, bumblebees and other insects have been used commercially for pollination for many years, and microbial biocontrol agents have also been widely used in pest control. Pollinators and formulations of microbial pest-control agents are routinely transported internationally on a large scale. A novel approach has been developed to use bees as vectors of microbial agents by inoculating the surface of the pollinators using dispensers in modified hives. This innovation extends the market for these products and results in better yields. A successful entomovector system requires selecting the vector pollinator most appropriate for the crop and location, based on various criteria, in combination with a registered microbial agent. Currently, pollinators and microbial agents are packed separately and combined at the point of use. Local sourcing of the pollinator in the system reduces the need for long-distance shipping of these live insects and may improve efficiency due to local adaptation; however, it will delay use and benefits of the system until research at each site/country catches up with the work already conducted in a few countries. In the meantime, clear guidance for innovative systems employing live insects could support the promising increase in food production.

Depuis plusieurs années, les abeilles mellifères, les bourdons et d'autres insectes sont commercialisés à des fins de pollinisation, parallèlement à l'utilisation désormais largement répandue de micro-organismes pour la lutte biologique contre les nuisibles. Les pollinisateurs et diverses formulations d'agents microbiens destinés à la lutte contre les nuisibles font régulièrement l'objet de transports internationaux à grande échelle. Une approche innovante mise au point récemment consiste à utiliser les abeilles en tant que vecteurs d'agents microbiens, en inoculant ces derniers sur la surface du pollinisateur par le biais de diffuseurs disposés dans les ruches modifiées à cette fin. Cette innovation amplifie le marché de ces produits et se traduit par un meilleur rendement. La réussite d'un système d'entomovection passe par la sélection judicieuse du vecteur pollinisateur en fonction des cultures à protéger et du site, sur la base de plusieurs critères, et par son utilisation en association avec un agent antimicrobien autorisé. À l'heure actuelle, les pollinisateurs et les agents microbiens sont conditionnés séparément et leur assemblage est effectué sur le site même d'utilisation. L'approvisionnement local en pollinisateurs au sein du système réduit la nécessité de transporter ces insectes vivants sur de longues distances et pourrait améliorer l'efficacité du système au moyen d'adaptations locales ; néanmoins, cela retardera la mise en oeuvre du système et l'obtention de résultats bénéfiques, le temps que la recherche conduite dans les sites ou les pays utilisateurs atteigne le niveau des avancées déjà enregistrées dans un petit nombre d'autres pays. En attendant, des directives claires en faveur des systèmes innovants basés sur l'utilisation d'insectes vivants pourraient oeuvrer à l'appui d'une croissance prometteuse de la production alimentaire.

El uso comercial de abejas melíferas, abejorros y otros insectos con fines de polinización tiene ya muchos años. También está muy extendido el empleo de agentes microbianos de control biológico como método de lucha contra las plagas. El transporte internacional y a gran escala de polinizadores y de ciertas formulaciones de plaguicidas microbianos es algo muy habitual. Ahora se ha concebido un novedoso planteamiento en el que se utilizan ápidos como vectores de agentes microbianos. Para ello, se impregna de estos agentes la superficie del insecto polinizador empleando dispensadores en colmenas modificadas. Tal innovación amplía el mercado de estos productos y depara mejores cosechas. Para que un sistema entomovectorial sea eficaz es preciso seleccionar el vector polinizador que mejor encaje con el cultivo y las condiciones locales atendiendo a diversos criterios y combinarlo con un agente microbiano registrado. Actualmente, los polinizadores y los agentes microbianos se embalan por separado y se combinan solo en el punto de aplicación. El aprovisionamiento del polinizador del sistema a partir de fuentes locales hace menos necesarios los envíos a larga distancia de estos insectos vivos y puede ofrecer más eficacia gracias al mayor grado de adaptación del insecto a las condiciones locales. Sin embargo, ello retrasará el uso del sistema y la obtención de los consiguientes beneficios, pues habrá que esperar a que en cada lugar o país se haya llevado el procedimiento tan lejos como se ha hecho hasta ahora en unos pocos países. Mientras tanto, la existencia de claras pautas sobre estos innovadores sistemas en que se emplean insectos vivos podría traducirse en un prometedor aumento de la producción alimentaria.