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CCD/Neonicotinoid Data (Studies, Articles, Links)

88K views 214 replies 40 participants last post by  Litsinger 
#1 ·
Use this thread to post Articles, Studies or Links that apply to the topic of CCD.
This will allow members to have all supporting data in one place.

This thread is NOT for discussion.
Post supporting data only. Discuss data in other threads.
 
#146 ·
Re: Gene expression changes in honey bees induced by sublethal imidacloprid exposure

https://www.ncbi.nlm.nih.gov/pubmed/29499530

Sci Total Environ. 2018 Feb 27;630:487-494. doi: 10.1016/j.scitotenv.2018.02.258. [Epub ahead of print]

Enhancement of chronic bee paralysis virus levels in honeybees acute exposed to imidacloprid: A Chinese case study.

Diao Q1, Li B1, Zhao H2, Wu Y1, Guo R3, Dai P1, Chen D3, Wang Q1, Hou C4.

Abstract
Though honeybee populations have not yet been reported to be largely lost in China, many stressors that affect the health of honeybees have been confirmed. Honeybees inevitably come into contact with environmental stressors that are not intended to target honeybees, such as pesticides. Although large-scale losses of honeybee colonies are thought to be associated with viruses, these viruses usually lead to covert infections and to not cause acute damage if the bees do not encounter outside stressors. To reveal the potential relationship between acute pesticides and viruses, we applied different doses of imidacloprid to adult bees that were primarily infected with low levels (4.3×105 genome copies) of chronic bee paralysis virus (CBPV) to observe whether the acute oral toxicity of imidacloprid was able to elevate the level of CBPV. Here, we found that the titer of CBPV was significantly elevated in adult bees after 96h of acute treatment with imidacloprid at the highest dose 66.9ng/bee compared with other treatments and controls. Our study provides clear evidence that exposure to acute high doses of imidacloprid in honeybees persistently infected by CBPV can exert a remarkably negative effect on honeybee survival. These results imply that acute environmental stressors might be one of the major accelerators causing rapid viral replication, which may progress to cause mass proliferation and dissemination and lead to colony decline. The present study will be useful for better understanding the harm caused by this pesticide, especially regarding how honeybee tolerance to the viral infection might be altered by acute pesticide exposure.
 
#150 ·
I wasn't 'discussing' - as a graduate in both Organic Chemistry and General Biology, I was simply correcting a false assumption. One which is frequently applied to the issues of CCD, Neonicotinoids - and many others currently related to beekeeping.
LJ
 
#149 ·
SiWolke, there has been discussion taking place in all 8 pages of this thread, even by yourself. Perhaps you would like only discussion favouring only your point of view? As a beekeeper surrounded by agriculture using neonics I generally have less than a 10% loss each year. However I had a small yard where I could not keep my colonies alive and one day while visiting that yard I saw a neighbor spraying in his vegetable garden so I wandered over there and asked what he was spraying with to which he replied Sevin, well I no longer keep bees there as I know why I could not keep them alive.
Now the moral of the story is Neonics could harm bees, it is an insecticide but some of the stuff the Ag sector used to use before Neonics was a lot worse and killed a lot more bees. And the story about proof, who needs proof when we have a consensus of scientists just like the consensus of scientists who believed the world was flat before Gallileo came along well you know that story. It appears that today the consensus of scientists is mainly a consensus of political science graduates.
Johno
 
#151 · (Edited)
SiWolke, there has been discussion taking place in all 8 pages of this thread, even by yourself.
Yes but I learned. I did not realize. Never again. It´s hard to find the links if you want to use them again if there is discussion between.

There are many other threads in this sub forum with discussion about the topics.

Little_john
that´s interesting, please post your links if they are contradiction

Bernhard, many thanks for keeping us updated. :)
 
#153 ·
Re: Gene expression changes in honey bees induced by sublethal imidacloprid exposure

Influences of acephate and mixtures with other commonly used pesticides on honey bee (Apis mellifera) survival and detoxification enzyme activities

Jianxiu Yaoa, Yu Cheng Zhua, John Adamczyk, Randall Luttrell
https://www.sciencedirect.com/science/article/pii/S1532045618300218
https://doi.org/10.1016/j.cbpc.2018.03.005

Abstract
Acephate (organophosphate) is frequently used to control piercing/sucking insects in field crops in southern United States, which may pose a risk to honey bees. In this study, toxicity of acephate (formulation Bracket®97) was examined in honey bees through feeding treatments with sublethal (pollen residue level: 0.168 mg/L) and median-lethal (LC50: 6.97 mg/L) concentrations. Results indicated that adult bees treated with acephate at residue concentration did not show significant increase in mortality, but esterase activity was significantly suppressed. Similarly, bees treated with binary mixtures of acephate with six formulated pesticides (all at residue dose) consistently showed lower esterase activity and body weight. Clothianidin, λ-cyhalothrin, oxamyl, tetraconazole, and chlorpyrifos may interact with acephate significantly to reduce body weight in treated bees. The dose response data (LC50: 6.97 mg/L) revealed a relatively higher tolerance to acephate in Stoneville bee population (USA) than populations elsewhere, although in general the population is still very sensitive to the organophosphate. In addition to killing 50% of the treated bees acephate (6.97 mg/L) inhibited 79.9%, 20.4%, and 29.4% of esterase, Glutathione S-transferase (GST), and acetylcholinesterase (AChE) activities, respectively, in survivors after feeding treatment for 48 h. However, P450 activity was elevated 20% in bees exposed to acephate for 48 h. Even though feeding on sublethal acephate did not kill honey bees directly, chronic toxicity to honey bee was noticeable in body weight loss and esterase suppression, and its potential risk of synergistic interactions with other formulated pesticides should not be ignored.
 
#154 ·
Re: Gene expression changes in honey bees induced by sublethal imidacloprid exposure

Have a quick look at:

http://www.agrofog.com/brochures/bayer-premise200sc.pdf

That's an ad from the manufacturer of the pesticide. Read carefully what a neonic does. It boils down to: chemical plus nature. The rest is self-explaining.

Good luck to you all. Gonna be tough times, for both: bees and beekeepers that make a living from their bees.
 
#155 ·
Re: Gene expression changes in honey bees induced by sublethal imidacloprid exposure

Have a quick look at:

http://www.agrofog.com/brochures/bayer-premise200sc.pdf

That's an ad from the manufacturer of the pesticide. Read carefully what a neonic does. It boils down to: chemical plus nature. The rest is self-explaining.

Good luck to you all. Gonna be tough times, for both: bees and beekeepers that make a living from their bees.
The one in the link is of particular concern: half life of 355 days.
 
#156 ·
Re: Gene expression changes in honey bees induced by sublethal imidacloprid exposure

Carreck, Norman and Ratnieks, Francis (2014) The dose makes the poison: have "field realistic" rates of exposure of bees to neonicotinoid insecticides been overestimated in laboratory studies? Journal of Apicultural Research, 53 (5). pp. 607-614. ISSN 0021-8839
|"Recent laboratory based studies have demonstrated adverse sub-lethal effects of neonicotinoid insecticides on honey bees and bumble bees, and these studies have been influential in leading to a European Union moratorium on the use of three neonicotinoids, clothianidin, imidacloprid, and thiamethoxam on "bee attractive" crops. Yet so far, these same effects have not been observed in field studies. Here we review the three key dosage factors (concentration, duration and choice) relevant to field conditions, and conclude that these have probably been over estimated in many laboratory based studies."
https://www.tandfonline.com/doi/abs/10.3896/IBRA.1.53.5.08

Three years of banning neonicotinoid insecticides based on sub‐lethal effects: can we expect to see effects on bees?
Tjeerd Blacquière Jozef JM van der Steen
First published: 03 April 2017 https://doi.org/10.1002/ps.4583 Cited by: 4
Although no direct relationship between colony losses and the decline of numbers of honey bee colonies could be shown (see section 4), losses of a high number of colonies over winter are considered to be a problem in itself for beekeepers, and have stimulated the foundation of the Coloss network.14 So could honey bee colony losses experienced by beekeepers be attributed to the use of neonicotinoids? Smith et al.11 point out that the evidence is not strong for the case. Even a very extensive 4‐year monitoring project set‐up with the intention to shed light on the possible factors involved in honey bee colony losses, and specifically focusing on residues of chemicals,19 was not able to show any relationship with these, but did show effects of infestation with the Varroa mite, some viruses and the age of the queen: actually all being part of the management choices of the beekeeper, a decisive factor often overlooked.
https://onlinelibrary.wiley.com/doi/full/10.1002/ps.4583

Environ Health Perspect; DOI:10.1289/EHP515
Effects of Neonicotinoid Pesticide Exposure on Human Health: A Systematic Review
Andria M. Cimino,1 Abee L. Boyles,2 Kristina A. Thayer,2 and Melissa J. Perry1
To the authors’ knowledge, this is the first systematic review of the literature on human health effects of neonicotinoids. As reviewed here, four studies reported low rates of adverse health effects from acute neonic exposure. Even the most severe outcomes, including two fatalities, may have been mediated by other factors (age, underlying health conditions, undetected coexposures). The acute poisoning studies did, however, elucidate clinical findings important for the diagnosis and treatment of acute neonic exposures, including a better understanding of neonic toxicokinetics in humans. The other four studies reported associations between chronic neonic exposure and adverse developmental outcomes or a symptom cluster including neurological effects. The findings of animal studies support the biological plausibility for such associations (Abou-Donia et al. 2008; Gibbons et al. 2015; Gu et al. 2013; Kimura-Kuroda et al. 2012; Li et al. 2011; Mason et al. 2013; Tomizawa 2004).

Although the studies in this review represent an important contribution to the literature, particularly given the lack of any general population chronic exposure studies prior to 2014, there remains a paucity of data on neonic exposure and human health. Given the widespread use of neonics in agriculture and household products and its increasing detection in U.S. food and water, more studies on the human health effects of chronic (non-acute) neonic exposure are needed.
https://ehp.niehs.nih.gov/ehp515/
 
#161 ·
Re: Gene expression changes in honey bees induced by sublethal imidacloprid exposure

Thanks, Eduardo;

A good example of very weak research designed to support an ideological opinion.

People susceptible to this kind of persuasion are generally not inclined to dig deep enough to spot the issues that could suggest very different causes for the observations.

Precise science is not needed to appeal to emotions!
 
#162 ·
Re: Gene expression changes in honey bees induced by sublethal imidacloprid exposure

Scientists are scientists.
Look at the dates.

I´m very sad that links are still discussed here.
Well, Barry left and moderation changed.


Threads
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says it all.
 
#163 ·
Re: Gene expression changes in honey bees induced by sublethal imidacloprid exposure

Threads
148,053
Posts
1,578,298
Members
34,726
Active Members
1,984


says it all.
Hello Sibylle - I may be having one of my really 'thick' days today - but what do you mean by "says it all" ? You've flagged-up nearly two thousand active members, so I guess that's part of the point you're making ...

Maybe I've missed something important within the last few posts ?
'best
LJ
 
#165 ·
Re: Gene expression changes in honey bees induced by sublethal imidacloprid exposure

Effects of clothianidin exposure on semen parameters of honey bee drones.
Abstract : Many problems have been reported on honey bees colonies including fertility problems of queens resulted in production failure. Pesticides can be the cause of this failure in connection with the quality of sperm drone. Thus, the aim of this study was to assess the influence of exposure to syrup contaminated with clothianidin at 0.1 µg/L on semen parameters of drones. Results showed a significant decrease of semen volume and sperm concentration and an increase in sperm mortality rate. As for the energetic state, clothianidin increased cell redox potential, the ATP content of spermatozoa as well as the lactate dehydrogenase activity (LDH). It was concluded that exposure to clothianidin during the sexual maturity of drones could affect the semen quality.
https://www.cabdirect.org/cabdirect/abstract/20193066560

Parameterization and sensitivity analysis of a honey bee colony dynamics model for neonicotinoid exposure events using Markov Chain Monte Carlo methods
Abstract
Honey bee (Apis mellifera) colony losses have increased in recent decades in both Europe and North America. While multiple stressors to honey bee colonies appear to be driving this decline (including disease, nutrition, genetics), direct exposure to pesticides has been identified as a factor leading to increased bee declines. The simulation model VarroaPop is currently being modified by the USDA and USEPA to predict honey bee hive dynamics in response to pesticide exposure. However, applying this model to pesticides is complicated due to a lack of parameterization information from the supporting literature for many variables, especially those related to in-hive pesticide dynamics. Here, we utilize data from a field study which measured residues of several neonicotinoid insecticides in pollen and tracked population dynamics of exposed hives to improve our estimation of colony simulation model parameters relevant to VarroaPop and the new model components related to pesticides. We use Markov Chain Monte Carlo methods to sample the probability distribution of model parameters and examine the likelihood of each parameter combination, given the field-derived population data. Through this procedure, we obtain posterior distributions which represent the most likely parameter values given a realistic neonicotinoid exposure scenario. We use these pesticide-optimized parameter distributions to run a global sensitivity analysis for the updated posteriors in order to contrast with a sensitivity analysis based on the priors. This helps determine what factors are most important in driving hive success or failure following exposure events.
https://scholarsarchive.byu.edu/iemssconference/2018/Stream-G/7/

Assessing the Impact of the Conservation Reserve Program on Honey Bee Health
Key Findings (2014–18)
• More than one-sixth of all honey bee yards in North Dakota and South Dakota (the top two honey-producing States) meet the key foraging requirements of honey bees just based on the existence of CRP grasslands alone. Thus, the CRP plays a considerable role in supporting the carrying capacity of honey bee colonies in this region (Otto and others, 2018).
• Honey bee colonies in areas surrounded by grassland, such as those enrolled in the CRP, are 10–15 percent larger than colonies kept in areas surrounded by mostly row crops. A USGS study determined that a bee yard surrounded by mostly grassland can yield an extra $4,100 in annual revenue to a beekeeper compared to a bee yard surrounded by mostly row crop. A beekeeper who manages several hundred bee yards may incur sizable economic gains through nearby CRP and other conservation grass- lands (Smart and others, 2018).
• The USGS led the first large-scale assessment of native bees on CRP grassland that documented what native bees were present on CRP grasslands and what flowers they used (Otto and others, 2017).
• The USGS developed a genetic sequencing strategy to rapidly quantify pollen grains collected from bees (Smart and others, 2017). This novel technique allowed the USGS to determine what flowering plants were impor- tant bee food. Knowing what flowers constitute good
bee food is an important step in improving the cost- effectiveness of the CRP.
• The USGS launched the “Pollinator Library,” a decision- support tool that can be used by USDA staff for evalu- ating seeding mixes for the CRP (https://www.npwrc. usgs.gov/pollinator/). This website provides users with information on which plants are favored by honey bees and native bees. USGS scientists published a paper demonstrating how USDA staff can use the Pollinator Library to evaluate the cost-effectiveness of CRP seeding mixes (Otto and others, 2017).
https://pubs.usgs.gov/fs/2018/3082/fs20183082.pdf

Hazard of a neonicotinoid insecticide on the homing flight of the honeybee depends on climatic conditions and Varroa infestation
Abstract
The paradigm for all toxicological bioassays in the risk assessment of pesticide registration reflects the principle that experimental conditions should be controlled to avoid any other factors that may affect the endpoint measures. As honeybee colonies can be frequently exposed to bio-aggressors in real conditions, often concomitantly with pesticides, co-exposure to pesticide/bio-aggressors is becoming a concern for regulatory authorities. We investigated the effects of the neonicotinoid insecticide thiamethoxam on the homingperformances of foragers emerging from colonies differentiated by health status (infestation with Varroa destructor mites, microsporidian parasite Nosema spp. and Deformed Wing Virus). We designed a homing test that has been recently identified to fill a regulatory gap in the field evaluations of sublethal doses of pesticides before their registration. We also assessed the effect of temperature as an environmental factor. Our results showed that the Varroa mite exacerbates homing failure (HF) caused by the insecticide, whereas high temperatures reduce insecticide-induced HF. Through an analytical Effective Dose (ED) approach, predictive modeling results showed that, for instance, ED level of an uninfested colony, can be divided by 3.3 when the colony is infested by 5 Varroa mites per 100 bees and at a temperature of 24 °C. Our results suggest that the health status of honeybee colonies and climatic context should be targeted for a thorough risk assessment.
https://www.sciencedirect.com/science/article/pii/S0045653519303534
 
#166 ·
Alterations in honey bee gut microorganisms
Honey bees are associated with gut microorganisms essential for their nutrition and health. The composition of the microbial community can be used as a biological health indicator and is characterized using biomarker fatty acids. Commonly, gut microorganisms are exposed to pathogens and to an array of chemical and biological pest control methods.


We found a strong negative effect on microbial gut community composition when exposed to the bee pest control chemicals oxytetracycline, oxalic acid and imidacloprid, and when inoculated with the bee pest Nosema spp. and the potential bee pest biocontrol agent Lactobacillus plantarum. Results from the in vitro test with bee pest chemicals showed a differential response of Lactobacillus spp. At the community level, some taxonomic groups were more affected depending on treatment, but sharp changes in the microbial structure were caused by compounds generally considered as bee safe.


Our results show that pests such as Nosema spp. and pest control methods alter the composition of bee gut microorganisms, which may have severe consequences for pathogen defense, physiology and general honey bee health. In addition, L. plantarum has potential as a biocontrol agent against Nosema spp. © 2018 Society of Chemical Industry
https://www.ingentaconnect.com/content/jws/ps/2019/00000075/00000003/art00035
 
#171 ·
Alterations in honey bee gut microorganisms
Honey bees are associated with gut microorganisms essential for their nutrition and health. The composition of the microbial community can be used as a biological health indicator and is characterized using biomarker fatty acids. Commonly, gut microorganisms are exposed to pathogens and to an array of chemical and biological pest control methods.


We found a strong negative effect on microbial gut community composition when exposed to the bee pest control chemicals oxytetracycline, oxalic acid and imidacloprid, and when inoculated with the bee pest Nosema spp
https://www.ingentaconnect.com/content/jws/ps/2019/00000075/00000003/art00035
I wonder if that is dribbled or vaporized OA. I read the link but I didn't see which.

Alex
 
#167 ·
Sublethal Effects of the Insecticide Pyrifluquinazon on the European Honey Bee (Hymenoptera: Apidae)
James M Wilson Troy D Anderson Thomas P Kuhar
Journal of Economic Entomology, toz014, https://doi.org/10.1093/jee/toz014

Abstract
Pyrifluquinazon (PQZ) is an Insecticide Resistance Action Committee (IRAC) Group 9 insecticide that has recently been registered for use in the United States for control of soft-bodied sucking insect pests. Although it has been classified as practically nontoxic to honey bees, Apis mellifera L. (Hymenoptera: Apidae), based on acute contact bioassays, additional information on sublethal effects of this insecticide on honey bees is lacking. Using a combination of laboratory assays with video movement tracking software and near-field evaluations of colonies foraging in a high-tunnel experiment, we determined that, when fed PQZ at a concentration of 84 mg active ingredient (ai)/liter (= ppm) in sugar water, a reduction in overall movement by the foraging worker bees was observed. However, when provided with honey reserves in the hive, honey bees rejected the PQZ-treated sugar water. These results indicate that, if ingested at levels of 84 mg ai/liter, PQZ could have a negative effect on honey bee behavior; however, honey bee workers appear to be able to detect the presence of PQZ in their food and reject it.
https://academic.oup.com/jee/advance-article-abstract/doi/10.1093/jee/toz014/5320965
 
#168 ·
Honey Bee Exposure to Pesticides: A Four-Year Nationwide Study
Abstract
Pollinators, including honey bees, are responsible for the successful reproduction of more than 87% of flowering plant species: they are thus vital to ecosystem health and agricultural services world-wide. To investigate honey bee exposure to pesticides, 168 pollen samples and 142 wax comb samples were collected from colonies within six stationary apiaries in six U.S. states. These samples were analyzed for evidence of pesticides. Samples were taken bi-weekly when each colony was active. Each apiary included thirty colonies, of which five randomly chosen colonies in each apiary were sampled for pollen. The pollen samples were separately pooled by apiary. There were a total of 714 detections in the collected pollen and 1008 detections in collected wax. A total of 91 different compounds were detected: of these, 79 different pesticides and metabolites were observed in the pollen and 56 were observed in the wax. In all years, insecticides were detected more frequently than were fungicides or herbicides: one third of the detected pesticides were found only in pollen. The mean (standard deviation (SD)) number of detections per pooled pollen sample varied by location from 1.1 (1.1) to 8.7 (2.1). Ten different modes of action were found across all four years and nine additional modes of action occurred in only one year. If synergy in toxicological response is a function of simultaneous occurrence of multiple distinct modes of action, then a high frequency of potential synergies was found in pollen and wax-comb samples. Because only pooled pollen samples were obtained from each apiary, and these from only five colonies per apiary per year, more data are needed to adequately evaluate the differences in pesticide exposure risk to honey bees among colonies in the same apiary and by year and location.
https://www.mdpi.com/2075-4450/10/1/13
 
#169 ·
Insects 2019, 10(1), 19; https://doi.org/10.3390/insects10010019
Initial Exposure of Wax Foundation to Agrochemicals Causes Negligible Effects on the Growth and Winter Survival of Incipient Honey Bee (Apis mellifera) Colonies
Abstract
Widespread use of agrochemicals in the U.S. has led to nearly universal contamination of beeswax in honey bee hives. The most commonly found agrochemicals in wax include beekeeper-applied miticides containing tau-fluvalinate, coumaphos, or amitraz, and field-applied pesticides containing chlorothalonil or chlorpyrifos. Wax contaminated with these pesticides negatively affects the reproductive quality of queens and drones. However, the synergistic effects of these pesticides on the growth and survival of incipient colonies remain understudied. We established new colonies using frames with wax foundation that was pesticide free or contaminated with field-relevant concentrations of amitraz alone, a combination of tau-fluvalinate and coumaphos, or a combination of chlorothalonil and chlorpyrifos. Colony growth was assessed by estimating comb and brood production, food storage, and adult bee population during a colony’s first season. We also measured colony overwintering survival. We found no significant differences in colony growth or survivorship between colonies established on pesticide-free vs. pesticide-laden wax foundation. However, colonies that had Varroa destructor levels above 3% in the fall were more likely to die over winter than those with levels below this threshold, indicating that high Varroa infestation in the fall played a more important role than initial pesticide exposure of wax foundation in the winter survival of newly established colonies.
https://www.mdpi.com/2075-4450/10/1/19
 
#170 ·
Combined Toxicity of Insecticides and Fungicides Applied to California Almond Orchards to Honey Bee Larvae and Adults
Insects 2019, 10(1), 20; https://doi.org/10.3390/insects10010020
Abstract
Beekeepers providing pollination services for California almond orchards have reported observing dead or malformed brood during and immediately after almond bloom—effects that they attribute to pesticide exposure. The objective of this study was to test commonly used insecticides and fungicides during almond bloom on honey bee larval development in a laboratory bioassay. In vitro rearing of worker honey bee larvae was performed to test the effect of three insecticides (chlorantraniliprole, diflubenzuron, and methoxyfenozide) and three fungicides (propiconazole, iprodione, and a mixture of boscalid-pyraclostrobin), applied alone or in insecticide-fungicide combinations, on larval development. Young worker larvae were fed diets contaminated with active ingredients at concentration ratios simulating a tank-mix at the maximum label rate. Overall, larvae receiving insecticide and insecticide-fungicide combinations were less likely to survive to adulthood when compared to the control or fungicide-only treatments. The insecticide chlorantraniliprole increased larval mortality when combined with the fungicides propiconazole or iprodione, but not alone; the chlorantraniliprole-propiconazole combination was also found to be highly toxic to adult workers treated topically. Diflubenzuron generally increased larval mortality, but no synergistic effect was observed when combined with fungicides. Neither methoxyfenozide nor any methoxyfenozide-fungicide combination increased mortality. Exposure to insecticides applied during almond bloom has the potential to harm honey bees and this effect may, in certain instances, be more damaging when insecticides are applied in combination with fungicides
https://www.mdpi.com/2075-4450/10/1/20
 
#174 ·
The novel pesticide flupyradifurone (Sivanto) affects honeybee motor abilities

Abstract
Honeybees and other pollinators are threatened by changing landscapes and pesticides resulting from intensified agriculture. In 2018 the European Union prohibited the outdoor use of three neonicotinoid insecticides due to concerns about pollinators. A new pesticide by the name of “Sivanto” was recently released by Bayer AG. Its active ingredient flupyradifurone binds to the nicotinic acetylcholine receptor (AchR) in the honeybee brain, similar to neonicotinoids. Nevertheless, flupyradifurone is assumed to be harmless for honeybees and can even be applied on flowering crops. So far, only little has been known about sublethal effects of flupyradifurone on honeybees. Intact motor functions are decisive for numerous behaviors including foraging and dancing. We therefore selected a motor assay to investigate in how far sublethal doses of this pesticide affect behavior in young summer and long-lived winter honeybees. Our results demonstrate that flupyradifurone (830 µmol/l) can evoke motor disabilities and disturb normal motor behavior after a single oral administration (1.2 µg/bee). These effects are stronger in long-lived winter bees than in young summer bees. After offering an equal amount of pesticide (1.0–1.75 µg) continuously over 24 h with food the observed effects are slighter. For comparisons we repeated our experiments with the neonicotinoid imidacloprid. Intriguingly, the alterations in behavior induced by this pesticide (4 ng/bee) were different and longer-lasting compared to flupyradifurone, even though both substances bind to nicotinic acetylcholine receptors.
https://link.springer.com/article/10.1007/s10646-019-02028-y
https://doi.org/10.1007/s10646-019-02028-y
 
#175 ·
DETECTION OF THE PESTICIDE IMIDACLOPRID IN HONEY

K. E. Burkin

Abstract: Studies have been carried out to determine the imidacloprid pesticide content of the neonicotinoid group in honey, including sample preparation and subsequent analysis by high-performance liquid chromatography on a chromatograph with a UV-detector. The optimum conditions providing the maximum extraction of imidacloprid from honey are selected.

http://tipkadpo.ru/data/uploads/nauka/konferencii/2018/_2018__.pdf#page=83
 
#176 ·
Impact of acute oral exposure to thiamethoxam on the homing, flight, learning acquisition and short‐term retention of Apis cerana

Changsheng Ma Yongkui Zhang Jia Sun Muhammad Imran Huipeng Yang Jie Wu … other authors /et al.
First published: 18 March 2019
https://doi.org/10.1002/ps.5411
https://onlinelibrary.wiley.com/doi/abs/10.1002/ps.5411

Abstract
BACKGROUND

Thiamethoxam (TMX) represents the second‐generation of neonicotinoids that has been widely applied in agricultural activities, while how TMX alters the behavior of Apis cerana, an important native honey bee species in China, is not clear. We carried out three independent experiments to study the impact of acute oral treatment of 20 μl TMX at concentrations of 2.4 ppb (0.048 ng/bee) and 10 ppb (0.2 ng/bee) on the homing, flight, learning acquisition and short‐term retention ability of A. cerana. The homing ability was assessed by the catch‐and‐release method, the flight ability was assessed by flight mills, and the learning acquisition and short‐term retention were evaluated by the proboscis extension response method.

RESULTS

When treated with 10 ppb of TMX, bees had a significantly higher average homing time, mean flight velocity, flying distance, and flying duration than the control, whereas 2.4 ppb concentration did not cause any significant effect on homing or flight ability. Bees treated with either 2.4 ppb or 10 ppb TMX had significantly lower learning acquisition and short‐term retention ability.

CONCLUSION

Results suggest that acute oral exposure to 10 ppb of TMX altered the short distance homing time, flight ability, and learning acquisition and short‐term retention ability. Our study also highlights the concern that acute oral exposure to a low concentration of 2.4 ppb could have consequences on the behavior of A. creana. Those multiple sublethal alterations on A. cerana's behavior indicate that TMX are likely causing complex, but negative consequences on bee health in the field.
 
#177 ·
Effects of sublethal doses of clothianidin and/or V. destructor on honey bee (Apis mellifera) self-grooming behavior and associated gene expression

Nuria Morfin, Paul H. Goodwin, Greg. J. Hunt & Ernesto Guzman-Novoa

Scientific Reportsvolume 9, Article number: 5196 (2019)


Abstract

Little is known about the combined effects of stressors on social immunity of honey bees (Apis mellifera) and related gene expression. The interaction between sublethal doses of a neurotoxin, clothianidin, and the ectoparasite, Varroa destructor, was examined by measuring differentially expressed genes (DEGs) in brains, deformed wing virus (DWV) and the proportion and intensity of self-grooming. Evidence for an interaction was observed between the stressors in a reduction in the proportion of intense groomers. Only the lowest dose of clothianidin alone reduced the proportion of self-groomers and increased DWV levels. V. destructor shared a higher proportion of DEGs with the combined stressors compared to clothianidin, indicating that the effects of V. destructor were more pervasive than those of clothianidin when they were combined. The number of up-regulated DEGs were reduced with the combined stressors compared to clothianidin alone, suggesting an interference with the impacts of clothianidin. Clothianidin and V. destructor affected DEGs from different biological pathways but shared impacts on pathways related to neurodegenerative disorders, like Alzheimer’s, which could be related to neurological dysfunction and may explain their negative impacts on grooming. This study shows that the combination of clothianidin and V. destructor resulted in a complex and non-additive interaction.

...


Discussion

This study examined the effect of two stressors, sublethal doses of clothianidin and V. destructor on gene expression in the brain and increases in a mite-transmitted virus, DWV, to better understand how these two stressors act separately and together to affect honey bees on aspects of neural activity related to self-grooming behavior. Among the two stressors, clothianidin alone had a greater effect than V. destructor alone to reduce self-grooming behavior, based on the proportion of bees that self-groomed and the proportion of bees that self-groomed intensively, as well as the number of up-regulated DEGs. However, the results with the combination of V. destructor with clothianidin showed that combining each stressor did not result in a simple additive effect in the number of DEGs or the KEGG pathways associated with them.

One unexpected result of this study was that both DWV levels and the proportion of bees that self-groomed were affected only by the lowest dose of clothianidin without V. destructor. This may indicate that effects of DWV and grooming could be linked in some manner. Unexpectedly, higher doses of clothianidin in absence of mites, or the same dose of clothianidin combined with V. destructor, did not have the same impacts, indicating that there was a relatively specific impact from the lowest dose of clothianidin tested. Hormesis occurs when there is a beneficial biological response to a low exposure to a stressor28. In this case, a beneficial response did not occur at the lowest dose, but the effect could be similar to hormesis. At the lowest clothianidin dose, it would still bind to nicotinic acetylcholine receptors of the neural cells resulting in neural stimulation but may not overstimulate it to the level of toxic doses that block receptors impeding the action of the neurotransmitter ACh29. At very low doses, clothianidin stimulation of the central nervous system may just be sufficient to somehow interfere with self-grooming and resistance to a virus. While these results imply hormesis, future research should investigate more sublethal doses of clothianidin to confirm this by determining the range of doses that results in these effects.

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#178 ·
Effects of three common pesticides on survival, food consumption and midgut bacterial communities of adult workers Apis cerana and Apis mellifera

YangYangaShilongMaabZhenxiongYancFengLiudQingyunDiaoaPingliDaia

https://doi.org/10.1016/j.envpol.2019.03.077

Highlights

Apis mellifera was more sensitive to chlorpyrifos and dimethoate than Apis cerana.


Amitraz at a concentration of 7.8 mg/L impacted Apis cerana survival.


Chlorpyrifos at a concentration of 3.0 mg/L impacted Apis cerana survival.


Dimethoate at a concentration of 1.0 mg/L impacted both Apis mellifera and Apis cerana survival.


There was a significant difference in microbiota species richness among treatments at day 15.


Abstract
The acute and chronic toxicity of 3 common pesticides, namely, amitraz, chlorpyrifos and dimethoate, were tested in Apis mellifera and Apis cerana. Acute oral toxicity LC50 values were calculated after 24 h of exposure to contaminated syrup, and chronic toxicity was tested after 15 days of exposure to 2 sublethal concentrations of pesticides. The toxicity of the tested pesticides to A. mellifera and A. cerana decreased in the order of dimethoate > chlorpyrifos > amitraz. A. mellifera was slightly more sensitive to chlorpyrifos and dimethoate than A. cerana, while A. cerana was more sensitive to amitraz than A. mellifera. Chronic toxicity tests showed that 1.0 mg/L dimethoate reduced the survival of the two bee species and the food consumption of A. mellifera, while 1.0 mg/L amitraz and 1.0 mg/L chlorpyrifos did not affect the survival or food consumption of the two bee species. The treatment of syrup with amitraz at a concentration equal to 1/10th of the LC50 value did not affect the survival of or diet consumption by A. mellifera and A. cerana; however, chlorpyrifos and dimethoate at concentrations equal to 1/10th of their respective LC50 values affected the survival of A. cerana. Furthermore, intestinal bacterial communities were identified using high-throughput sequencing targeting the V3V4 regions of the 16S rDNA gene. All major honey bee intestinal bacterial phyla, including Proteobacteria (62.84%), Firmicutes (34.04%), and Bacteroidetes (2.02%), were detected. There was a significant difference in the microbiota species richness of the two species after 15 days; however, after 30 days, no significant differences were found in the species diversity and richness between A. cerana and A. mellifera exposed to 1.0 mg/L amitraz and 1.0 mg/L chlorpyrifos. Overall, our results confirm that acute toxicity values are valuable for evaluating the chronic toxicity of these pesticides to honey bees.
 
#180 ·
Effects of three common pesticides on survival, food consumption and midgut bacterial communities of adult workers Apis cerana and Apis mellifera

YangYangaShilongMaabZhenxiongYancFengLiudQingyunDiaoaPingliDaia

https://doi.org/10.1016/j.envpol.2019.03.077

Highlights

Apis mellifera was more sensitive to chlorpyrifos and dimethoate than Apis cerana.


Amitraz at a concentration of 7.8 mg/L impacted Apis cerana survival.


Chlorpyrifos at a concentration of 3.0 mg/L impacted Apis cerana survival.


Dimethoate at a concentration of 1.0 mg/L impacted both Apis mellifera and Apis cerana survival.


There was a significant difference in microbiota species richness among treatments at day 15.
There's a hugely flawed study if I ever saw one! The concentrations of all of those is around the tank concentration used in the field. So even if the bees drank right from the sprayer on the tractor, they'd probably "bee" OK. For example 3.0 mg/L of chlorpyrifos = 0.3%; when you prepare chlorpyrifos for spraying you dilute it to 0.1% to 0.5% in the tank :lpf:
 
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