Effectiveness of method improvements to reduce variability of brood termination rate in honey bee brood studies under semi-field conditions

Pistorius, Jens; Becker, Roland; Lückmann, Johannes; Schur, Andrea; Barth, Markus; Jeker, Lukas; Schmitzer, Stephan; Ohe, Werner von der

doi:10.5073/jka.2012.437.033

Cited by 6 publications

(4 citation statements)

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“…Brood cannibalism in free-flying colonies occurs in response to environmental conditions and for seasonal regulation of the colony size (Woyke, 1977). A comprehensive study revealed a large variability in overall brood termination rates until emergence of the bees, especially for experiments initiated after the end of June (Pistorius et al, 2011), which is in line with our study. In this respect, it might be preferable to perform future studies a bit earlier in the season.…”

Section: Discussionsupporting

confidence: 90%

Toxicity of Coumaphos Residues in Beeswax Foundation to the Honey Bee Brood

Kast

Droz

Kilchenmann

2023

Enviro Toxic and Chemistry

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Coumaphos is one of the most frequently detected pesticides in recycled beeswax. The objective was to assess the maximal level of coumaphos in foundation sheets that could exist without lethal effects on the honey bee larvae. Brood development was followed in cells drawn on foundation squares containing coumaphos ranging from 0 to 132 mg/kg. Furthermore, larval exposure was determined by measuring the coumaphos level in the drawn cells. Coumaphos levels in the initial foundation sheets up to 62 mg/kg did not increase brood mortality because the emergence rates of bees raised on these foundation squares were similar to controls (median of 51%). After a single brood cycle, coumaphos levels in the drawn cells were up to three times lower than the initial levels in foundation sheets. Hence, coumaphos levels of 62 mg/kg in the initial foundation sheets, almost the highest exposures, resulted in levels of 21 mg/kg in drawn cells. A significantly reduced emergence rate (median of 14%) was observed for bees raised on foundation sheets with initial coumaphos levels of 132 mg/kg, indicating increased brood mortality. Such levels resulted in coumaphos concentrations of 51 mg/kg in drawn cells, which is close to the median lethal concentration (LC50) as determined in previous in vitro experiments. In conclusion, brood mortality was increased on wax foundation sheets with initial coumaphos levels of 132 mg/kg, while no elevated mortality was observed for levels up to 62 mg/kg. Environ Toxicol Chem 2023;42:1816–1822. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

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Section: Discussionsupporting

confidence: 90%

Toxicity of Coumaphos Residues in Beeswax Foundation to the Honey Bee Brood

Kast

Droz

Kilchenmann

2023

Enviro Toxic and Chemistry

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“…Our results provide slightly higher values, indicating suboptimal conditions for brood rearing, even though a flowering crop was present. Pistorius et al (2012) further highlighted that the ratio of crop area to colony strength plays a crucial role for successful colony development under semi-field conditions. They suggest ideally using >80 m 2 of crop area and a colony strength of about 7,000 bees per replicate.…”

Section: Discussionmentioning

confidence: 99%

A selected organosilicone spray adjuvant does not enhance lethal effects of a pyrethroid and carbamate insecticide on honey bees

et al. 2023

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As part of the agricultural landscape, non-target organisms, such as bees, may be exposed to a cocktail of agrochemicals including insecticides and spray adjuvants like organosilicone surfactants (OSS). While the risks of insecticides are evaluated extensively in their approval process, in most parts of the world however, authorization of adjuvants is performed without prior examination of the effects on bees. Nevertheless, recent laboratory studies evidence that adjuvants can have a toxicity increasing effect when mixed with insecticides. Therefore, this semi-field study aims to test whether an OSS mixed with insecticides can influence the insecticidal activity causing increased effects on bees and bee colonies under more realistic exposure conditions. To answer this question a pyrethroid (Karate Zeon) and a carbamate (Pirimor Granulat) were applied in a highly bee attractive crop (oil seed rape) during bee flight either alone or mixed with the OSS Break-Thru S 301 at field realistic application rates. The following parameters were assessed: mortality, flower visitation, population and brood development of full-sized bee colonies. Our results show that none of the above mentioned parameters was significantly affected by the insecticides alone or their combination with the adjuvant, except for a reduced flower visitation rate in both carbamate treatments (Tukey-HSD, p < 0.05). This indicates that the OSS did not increase mortality to a biologically relevant extent or any of the parameters observed on honey bees and colonies in this trial. Hence, social buffering may have played a crucial role in increasing thresholds for such environmental stressors. We confirm that the results of laboratory studies on individual bees cannot necessarily be extrapolated to the colony level and further trials with additional combinations are required for a well-founded evaluation of these substances.

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“…For the validation of BEEHAVE ecotox , semifield studies with the tunnel setup (“tunnel studies”) were chosen. Tunnel studies were chosen for validation because they combine controlled exposure and relatively free foraging (confined within the tunnel) and thus were deemed best for validating effect sizes (OECD, 2014 ; European and Mediterranean Plant Protection Organization, 2010 ; Pistorius et al, 2012 ). In addition, these study types provide detailed information in terms of adult and brood mortality and colony composition (adults, brood, nectar/honey, and pollen stores).…”

Section: Methodsmentioning

confidence: 99%

The BEEHAVE_ecotox Model—Integrating a Mechanistic Effect Module into the Honeybee Colony Model

Preuß

Agatz²,

Goussen³

et al. 2022

Enviro Toxic and Chemistry

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Mechanistic effect models are powerful tools for extrapolating from laboratory studies to field conditions. For bees, several good models are available that can simulate colony dynamics. Controlled and reliable experimental systems are also available to estimate the inherent toxicity of pesticides to individuals. However, there is currently no systematic and mechanistic way of linking the output of experimental ecotoxicological testing to bee models for bee risk assessment. We introduce an ecotoxicological module that mechanistically links exposure with the hazard profile of a pesticide for individual honeybees so that colony effects emerge. This mechanistic link allows the translation of results from standard laboratory studies to relevant parameters and processes for simulating bee colony dynamics. The module was integrated into the state‐of‐the‐art honeybee model BEEHAVE. For the integration, BEEHAVE was adapted to mechanistically link the exposure and effects on different cohorts to colony dynamics. The BEEHAVEecotox model was tested against semifield (tunnel) studies, which were deemed the best study type to test whether BEEHAVEecotox predicted realistic effect sizes under controlled conditions. Two pesticides used as toxic standards were chosen for this validation to represent two different modes of action: acute mortality of foragers and chronic brood effects. The ecotoxicological module was able to predict effect sizes in the tunnel studies based on information from standard laboratory tests. In conclusion, the BEEHAVEecotox model is an excellent tool to be used for honeybee risk assessment, interpretation of field and semifield studies, and exploring the efficiency of different mitigation measures. The principles for exposure and effect modules are portable and could be used for any well‐constructed honeybee model. Environ Toxicol Chem 2022;41:2870–2882. © 2022 Bayer AG & Sygenta, et al. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

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Effectiveness of method improvements to reduce variability of brood termination rate in honey bee brood studies under semi-field conditions

Cited by 6 publications

References 1 publication

Toxicity of Coumaphos Residues in Beeswax Foundation to the Honey Bee Brood

Toxicity of Coumaphos Residues in Beeswax Foundation to the Honey Bee Brood

A selected organosilicone spray adjuvant does not enhance lethal effects of a pyrethroid and carbamate insecticide on honey bees

The BEEHAVE_ecotox Model—Integrating a Mechanistic Effect Module into the Honeybee Colony Model

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Effectiveness of method improvements to reduce variability of brood termination rate in honey bee brood studies under semi-field conditions

Cited by 6 publications

References 1 publication

Toxicity of Coumaphos Residues in Beeswax Foundation to the Honey Bee Brood

Toxicity of Coumaphos Residues in Beeswax Foundation to the Honey Bee Brood

A selected organosilicone spray adjuvant does not enhance lethal effects of a pyrethroid and carbamate insecticide on honey bees

The BEEHAVEecotox Model—Integrating a Mechanistic Effect Module into the Honeybee Colony Model

Contact Info

Product

Resources

About

The BEEHAVE_ecotox Model—Integrating a Mechanistic Effect Module into the Honeybee Colony Model