Jozef van der Steen

Global declines of bumble bees and other pollinator populations are of concern because of their critical role for crop production and maintenance of wild plant biodiversity. Although the consensus among scientists is that the interaction of many factors, including habitat loss, forage scarcity, diseases, parasites, and pesticides potentially plays a role in causing these declines, pesticides have received considerable public attention and scrutiny. In response, regulatory agencies have introduced more stringent pollinator testing requirements for registration and re-registration of pesticides, to ensure the risks to pollinators are minimized. In this context, guidelines for testing bumble bees (Bombus spp.) in regulatory studies are not yet available and there is a pressing need to develop suitable protocols for routine higher tier studies with these non-Apis, social bees. To meet this need, Bayer CropScience LP, Syngenta Crop Protection LLC US, and Valent U.S.A. Corporation organized a workshop bringing together a group of global experts on bumble bee behavior, ecology and ecotoxicology to discuss and develop draft protocols for both semi-field (Tier II) and field (Tier III) studies. The workshop was held May 8-9, 2014 at the Bayer Bee Care Center, North Carolina. The participants represented academic, consulting, and industry scientists from Europe, Canada, USA, and Brazil. The workshop identified a clear protection goal and generated proposals for basic experimental designs, relevant measurements and endpoints for both semi-field (tunnel) and field tests. These initial recommendations are intended to form the basis of discussions to help advance the development of appropriate protocol guidelines. This article is protected by copyright. All rights reserved.

Several plant pathogenic fungi enter the plant trough open flowers. Spores of antagonistic micro-organisms present on the flowers can successfully compete with the possible pathogens. Honeybees and bumblebees can be used for transporting these antagonistic micro-organisms from the hive into flowers in order to prevent infections of the flowers. It is unavoidable that this antagonistic material also enters the brood nest of the bees. Since a healthy brood nest is an essential stimulant for the foraging activities of the bees and knowing that fungi and yeast may be able to cause infections of the brood, the effect of two antagonistic micro-organisms is tested on the honey bee and bumble bee brood. Eggs and larvae were contaminated and during the larval and pupal phase, samples were taken and checked for the presence these antagonistic micro-organisms. The antagonistic micro-organisms were not found in the samples and no significant changes in the broodnest were observed. These results...

Honeybees (Apis mellifera L.) and bumblebees (Bombus terrestris L.) are used for pollination in agriculture and horticulture. The morphological and behavioural characteristics of bees make them good pollinators. Thanks to this, bees may also be used as vector of antagonistic micro-organisms for plant disease control, both preventive and curative. To determine the practical consequences of this way of plant disease control, research has started on the two main aspects: the impact of the antagonist on the vector itself and the impact on the transmission of Botrytis aclada into seeds of onion. Preliminary tests for method development have been carried out to determine the impact on honeybees and bumblebees and on the dissemination of the antagonist over the flowering plants. Results: Trichoderma harzianum and PGBY1 have no negative impact in the brood of honeybees and bumblebees. Honeybees are rather effective vectors to transfer the antagonist Ulocladium atrum to onion flowers and thi...

Methods to determine the impact of pesticides on bumblebees are described. They are classified into laboratory tests to determine the acute toxicity and the hazard to bumblebees, (semi) field tests, and brood tests. The reproducibility and the significance of the data for practical purpose are discussed. Standardized laboratory toxicity tests supply reproducible data. In hazard tests, both in the laboratory and semi field tests, the exposure is not proportionate to the number of adult insects and the brood. Field tests provide realistic data on the hazard of a pesticide to bumblebee colonies but when the results are interpreted it must be taken in account that the test plot is only a portion of the total foraging area of a bumblebee colony. In a brood nest, due to the disorderly structure, only major effects can be recognized. Laboratory rearing of bumblebee brood should be developed to produce a standardized brood test that supplies reproducible data

Dat de varraomijt bestreden moet worden is voor iedere imker duidelijk. Niet bestrijden leidt tot zwakke volken en wintersterfte. Onderzoeken van PRI Bijen@wur en vele buitenlandse onderzoeksinstellingen komen, als het gaat over wintersterfte, altijd hetzelfde uit: de varroamijt is oorzaak nummer één

ABSTRACT Methods to determine the impact of pesticides on bumblebees are described. They are classified into laboratory tests to determine the acute toxicity and the hazard to bumblebees, (semi) field tests, and brood tests. The reproducibility and the significance of the data for practical purpose are discussed. Standardized laboratory toxicity tests supply reproducible data. In hazard tests, both in the laboratory and semi field tests, the exposure is not proportionate to the number of adult insects and the brood. Field tests provide realistic data on the hazard of a pesticide to bumblebee colonies but when the results are interpreted it must be taken in account that the test plot is only a portion of the total foraging area of a bumblebee colony. In a brood nest, due to the disorderly structure, only major effects can be recognized. Laboratory rearing of bumblebee brood should be developed to produce a standardized brood test that supplies reproducible data

ABSTRACT Overzicht van voorhanden bestrijdingsmethoden tegen Varroa destructor op de korte termijn en vooruitzichten voor de bestrijding op langere termijn. In de nabije toekomst gaat het om bestrijding met diergeneesmiddelen van natuurlijke oorsprong (mierenzuur, oxaalzuur, thymol) in het kader van een jaarbestrijdingsconcept. De verdere toekomst zal gericht zijn op het gebruik maken van natuurlijke vijanden (ziekteverwekkende virussen of schimmels) of natuurlijke signaalstoffen (feromonen), en het ontwikkelen van een varroaresistente bij door selectie op varroatolerantie

ABSTRACT Varroa is de belangrijkste ziekte van de Europese honingbij. Daar zijn onderzoekers in Nederland, maar ook in de rest van de wereld het over eens (Neumann & Carreck, 2010). Zelfs na jaren van praktijkervaring en experimenteel onderzoek blijft deze parasiet onze bijen teisteren. Dat is niet zo gek, want in de 27 jaar dat varroa in Nederland wordt aangetroffen, is er veel veranderd. De nieuwe brochure van Bijen@wur genaamd 'Effectieve bestrijding van varroa' biedt een overzicht

To evaluate the effect of the indoxacarb 300 g kg(-1) WG, Steward 30WDG, on the honey bee (Apis mellifera L.) in apple orchards, a monitoring study was conducted in Dutch apple orchards in April/May 2004. Before apple flowering began, two honey bee colonies were placed in each orchard to investigate honey bee mortality. Each hive was provided with a Münster dead bee trap to collect dead honey bees. The numbers of dead bees found in these Münster dead traps were counted every 3-4 days for about 2 weeks before and after the period of the insecticide treatment. In nine flowering orchards no indoxacarb was applied during the flowering period, which served as control sites. In 30 flowering orchards indoxacarb was sprayed by the fruit growers according to local practice at 170-260 g formulated product ha(-1) (51-78 g AI ha(-1)). In the control orchards the average mortality was 8 honey bees colony(-1) day(-1). The average daily honey bee mortality before and after indoxacarb application was 8 and 10 honey bees colony(-1) day(-1) respectively. At one test site, indoxacarb was mixed with other plant protection products plus plant nutrients, and in this orchard a slight but biologically non-significant increase in acute honey bee mortality was recorded. It was concluded that the application of indoxacarb caused no effects on honey bee mortality, and that the number of dead honey bees counted in the Münster traps in the orchard treated with indoxacarb was comparable with those determined in control orchards.