Adriaan van Doorn

Bio: Adriaan van Doorn is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 617 citations.

A century of advances in bumblebee domestication and the economic and environmental aspects of its commercialization for pollination

Abstract: D'un point de vue historique, le developpement de la technique d'elevage des bourdons (Bombus spp.) se caracterise par trois phases. Durant la 1 re phase, les reines ont ete attirees dans des domiciles artificiels et diverses techniques ont ete utilisees pour stimuler les reines a fonder une colonie. Les connaissances acquises durant cette phase ont rendu possibles les etudes de terrain concernant la biologie des bourdons. Elles ont aussi ete utilisees pour ameliorer la pollinisation des cultures dont la floraison etait synchrone du developpement naturel des colonies. La comprehension grandissante des mecanismes qui regulent l'activation des reines et leur production d'oeufs et des mecanismes qui gouvernent la colonie dans son ensemble a permis aux chercheurs d'elever des bourdons toute l'annee. La 3 e phase a vu la transition vers l'elevage commercial, technique qui necessite une connaissance plus detaillee des moyens pour maximiser la reussite de l'elevage. En moins de 20 ans, l'elevage commercial a atteint une production annuelle d'un million de colonies. Bien que de nombreuses especes, parmi les 250 existantes, aient ete elevees, seules cinq especes sont utilisees dans les programmes de pollinisation (Tab. III). Parmi ces cinq especes, l'espece eurasienne Bombus terrestris est de loin la plus importante sur le plan commercial, suivie par l'espece nord-americaine Bombus impatiens. Le tableau I fournit des details sur les pays qui utilisent ces especes et sur les societes qui les produisent et les vendent. L'acceptation rapide des bourdons et leur vaste introduction en tant que pollinisateurs peut s'expliquer par les avantages economiques par rapport aux techniques plus anciennes, souvent artificielles. La figure 1 montre la transition rapide qui s'est operee dans le cas des tomates sous serre aux Pays-Bas. Et la figure 2 l'accroissement des ventes mondiales. Le tableau II presente l'evolution dans le temps de l'expansion mondiale. Aujourd'hui les bourdons sont utilises pour la production agricole sur tous les continents. Bien qu'ils pollinisent des cultures de plein champ et des cultures sous cage (Tab. IV), leur utilisation predomine dans la production de tomates sous serre. Celle-ci couvre 40 000 ha et represente une valeur de 12 000 millions d'euros. La pollinisation par les bourdons entraine une baisse des couts de production, un accroissement des rendements et une meilleure qualite des fruits, ainsi qu'une plus grande utilisation de la lutte biologique contre les ravageurs des cultures. A cause de l'acceptation generale de la nouvelle technologie, les gains financiers pour les agriculteurs ont rapidement disparus tandis que le consommateur a continue de beneficier d'une meilleure qualite. La plupart des colonies ne sont produites que par un petit nombre de societes et sont transportees sur de longues distances. En fait elles sont expediees dans des regions eloignees de leur habitat d'origine. Il est donc justifie d'avoir des craintes sur les consequences ecologiques. Par exemple, B. terrestris a recemment ete implante au Japon, au Chili et en Tasmanie. La, il entre en competition avec les especes indigenes et peut transmettre des parasites et des pathogenes de bourdons a de nouveaux hotes. Il faut donc preferer la production locale de pollinisateurs autochtones.

Neonicotinoids in bees: a review on concentrations, side-effects and risk assessment

Abstract: Neonicotinoid insecticides are successfully applied to control pests in a variety of agricultural crops; however, they may not only affect pest insects but also non-target organisms such as pollinators. This review summarizes, for the first time, 15 years of research on the hazards of neonicotinoids to bees including honey bees, bumble bees and solitary bees. The focus of the paper is on three different key aspects determining the risks of neonicotinoid field concentrations for bee populations: (1) the environmental neonicotinoid residue levels in plants, bees and bee products in relation to pesticide application, (2) the reported side-effects with special attention for sublethal effects, and (3) the usefulness for the evaluation of neonicotinoids of an already existing risk assessment scheme for systemic compounds. Although environmental residue levels of neonicotinoids were found to be lower than acute/chronic toxicity levels, there is still a lack of reliable data as most analyses were conducted near the detection limit and for only few crops. Many laboratory studies described lethal and sublethal effects of neonicotinoids on the foraging behavior, and learning and memory abilities of bees, while no effects were observed in field studies at field-realistic dosages. The proposed risk assessment scheme for systemic compounds was shown to be applicable to assess the risk for side-effects of neonicotinoids as it considers the effect on different life stages and different levels of biological organization (organism versus colony). Future research studies should be conducted with field-realistic concentrations, relevant exposure and evaluation durations. Molecular markers may be used to improve risk assessment by a better understanding of the mode of action (interaction with receptors) of neonicotinoids in bees leading to the identification of environmentally safer compounds.

Climate-associated phenological advances in bee pollinators and bee-pollinated plants.

Abstract: The phenology of many ecological processes is modulated by temperature, making them potentially sensitive to climate change. Mutualistic interactions may be especially vulnerable because of the potential for phenological mismatching if the species involved do not respond similarly to changes in temperature. Here we present an analysis of climate-associated shifts in the phenology of wild bees, the most important pollinators worldwide, and compare these shifts to published studies of bee-pollinated plants over the same time period. We report that over the past 130 y, the phenology of 10 bee species from northeastern North America has advanced by a mean of 10.4 ± 1.3 d. Most of this advance has taken place since 1970, paralleling global temperature increases. When the best available data are used to estimate analogous rates of advance for plants, these rates are not distinguishable from those of bees, suggesting that bee emergence is keeping pace with shifts in host-plant flowering, at least among the generalist species that we investigated.

RNA Viruses in Hymenopteran Pollinators: Evidence of Inter-Taxa Virus Transmission via Pollen and Potential Impact on Non-Apis Hymenopteran Species

Abstract: Although overall pollinator populations have declined over the last couple of decades, the honey bee (Apis mellifera) malady, colony collapse disorder (CCD), has caused major concern in the agricultural community. Among honey bee pathogens, RNA viruses are emerging as a serious threat and are suspected as major contributors to CCD. Recent detection of these viral species in bumble bees suggests a possible wider environmental spread of these viruses with potential broader impact. It is therefore vital to study the ecology and epidemiology of these viruses in the hymenopteran pollinator community as a whole. We studied the viral distribution in honey bees, in their pollen loads, and in other non-Apis hymenopteran pollinators collected from flowering plants in Pennsylvania, New York, and Illinois in the United States. Viruses in the samples were detected using reverse transcriptase-PCR and confirmed by sequencing. For the first time, we report the molecular detection of picorna-like RNA viruses (deformed wing virus, sacbrood virus and black queen cell virus) in pollen pellets collected directly from forager bees. Pollen pellets from several uninfected forager bees were detected with virus, indicating that pollen itself may harbor viruses. The viruses in the pollen and honey stored in the hive were demonstrated to be infective, with the queen becoming infected and laying infected eggs after these virus-contaminated foods were given to virus-free colonies. These viruses were detected in eleven other non-Apis hymenopteran species, ranging from many solitary bees to bumble bees and wasps. This finding further expands the viral host range and implies a possible deeper impact on the health of our ecosystem. Phylogenetic analyses support that these viruses are disseminating freely among the pollinators via the flower pollen itself. Notably, in cases where honey bee apiaries affected by CCD harbored honey bees with Israeli Acute Paralysis virus (IAPV), nearby non-Apis hymenopteran pollinators also had IAPV, while those near apiaries without IAPV did not. In containment greenhouse experiments, IAPV moved from infected honey bees to bumble bees and from infected bumble bees to honey bees within a week, demonstrating that the viruses could be transmitted from one species to another. This study adds to our present understanding of virus epidemiology and may help explain bee disease patterns and pollinator population decline in general.