Traditionally, measurement of the acute toxicity of pesticides to beneficial arthropods has relied largely on the determination of an acute median lethal dose or concentration. However, the estimated lethal dose during acute toxicity tests may only be a partial measure of the deleterious effects. In addition to direct mortality induced by pesticides, their sublethal effects on arthropod physiology and behavior must be considered for a complete analysis of their impact. An increasing number of studies and methods related to the identification and characterization of these effects have been published in the past 15 years. Review of sublethal effects reported in published literature, taking into account recent data, has revealed new insights into the sublethal effects of pesticides including effects on learning performance, behavior, and neurophysiology. We characterize the different types of sublethal effects on beneficial arthropods, focusing mainly on honey bees and natural enemies, and we describe the methods used in these studies. Finally, we discuss the potential for developing experimental approaches that take into account these sublethal effects in integrated pest management and the possibility of integrating their evaluation in pesticide registration procedures.

The Sublethal Effects of Pesticides on Beneficial Arthropods

http://www.tsusinvasives.org/dotAsset/3b275f2a-205c-4012-b48a-038a13dddf8f.pdf

Biology and control of Varroa destructor

Adequate nutrition supports the development of healthy honey bee colonies. We give an overview of the nutritional demands of honey bee workers at three levels: (1) colony nutrition with the possibility of supplementation of carbohydrates and proteins; (2) adult nutrition and (3) larval nutrition. Larvae are especially dependant on protein and brood production is strongly affected by shortages of this nutrient. The number of larvae reared may be reduced to maintain the quality of remaining offspring. The quality of developing workers also suffers under conditions of larval starvation, leading to slightly affected workers. Larval starvation, alone or in combination with other stressors, can weaken colonies. The potential of different diets to meet nutritional requirements or to improve survival or brood production is outlined. We discuss nutrition-related risks to honey bee colonies such as starvation, monocultures, genetically modified crops and pesticides in pollen and nectar.

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Nutrition and health in honey bees

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.

/pdf/a-century-of-advances-in-bumblebee-domestication-and-the-3ycj51myxa.pdf

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

SummaryVery rapidly after Varroa destructor invaded apiaries of Apis mellifera, the devastating effect of this mite prompted an active research effort to understand and control this parasite. Over a few decades, varroa has spread to most countries exploiting A. mellifera. As a consequence, a large number of teams have worked with this organism, developing a diversity of research methods. Often different approaches have been followed to achieve the same goal. The diversity of methods made the results difficult to compare, thus hindering our understanding of this parasite. In this paper, we provide easy to use protocols for the collection, identification, diagnosis, rearing, breeding, marking and measurement of infestation rates and fertility of V. destructor. We also describe experimental protocols to study orientation and feeding of the mite, to infest colonies or cells and measure the mite's susceptibility to acaricides. Where relevant, we describe which mite should be used for bioassays since their beha...

Standard methods for varroa research

A method is proposed for testing the side-effects of plant protection products on honeybee brood, particularly aimed at products with insect growth-regulating properties. It is intended to complement the EPPO guideline on test methods for evaluating the side-effects of plant protection products on honeybees and to be used in the framework of the EPPO/CoE decision-making scheme on environmental risk assessment.

Method for honeybee brood feeding tests with insect growth‐regulating insecticides

Method for rearing bombus terrestris continuously and the production of bumblebee colonies for pollination purposes.

(1990). Year-Round Production of Bumble Bee Colonies for Crop Pollination. Bee World: Vol. 71, No. 2, pp. 54-56.

Year-Round Production of Bumble Bee Colonies for Crop Pollination

SUMMARYBiotechnical varroa (Varroa jacobsoni) control methods are based on the principle that mites inside brood cells are trapped and then removed from the bee colony. In our experiments trapped mites were killed with formic acid. Worker brood used for trapping was retained and returned to the colonies. The observed percentage of mites trapped and killed by formic acid treatment was 87% and 89% in two experiments. The effectiveness could be predicted using prior knowledge on brood cell invasion behaviour, which thus proved to be valid for the design and improvement of trap-comb methods for ecological varroa control.

Control of varroa by combining trapping in honey bee worker brood with formic acid treatment of the capped brood outside the colony : putting knowledge on brood cell invasion into practice

SummaryIn 2001 and 2002, studies were conducted on a pollen substitute formulated for easy home preparation. Tests were done with free flying honey bee colonies. In 2001, pollen supply was restricted with pollen traps in 9 experimental colonies. Colonies were then equally divided among three treatments: (1) fed pollen substitute, (2) fed bee-collected bee bread, or (3) no supplement. In 2002 the design was similar except that the bee bread treatment was replaced with a control treatment without pollen trap or supplements. The pollen substitute was readily consumed by bees, and brood development (fraction of larvae achieving pupa) did not differ among treatments. In 2002, longevity of bees was highest in colonies fed pollen substitute even though this group had a pollen trap. The average concentration of haemolymph protein did not differ among treatments in 2001, but in 2002 this value was significantly highest in colonies without a pollen trap. The results of this study are applicable for honey bee coloni...

J.J.M. van der Steen

Papers

Method for honeybee brood feeding tests with insect growth‐regulating insecticides

Method for rearing bombus terrestris continuously and the production of bumblebee colonies for pollination purposes.

Year-Round Production of Bumble Bee Colonies for Crop Pollination

Control of varroa by combining trapping in honey bee worker brood with formic acid treatment of the capped brood outside the colony : putting knowledge on brood cell invasion into practice

Effect of a home-made pollen substitute on honey bee colony development