scholarly journals Sub-lethal pesticide exposure erases colour vision memory and affects flower constancy in foraging honey bees

2021 ◽  
Author(s):  
Christopher Mayack ◽  
Tuğçe Rükün ◽  
Neslim Ercan ◽  
Ece Canko ◽  
Bihter Avşar ◽  
...  
Keyword(s):  
Honey Bees ◽  
Colour Vision ◽  
Pesticide Exposure ◽  
Flower Colour ◽  
Memory Retention ◽  
Pollination Services ◽  
Flower Constancy ◽  
Foraging Preferences ◽  
Bee Health ◽  
Neonicotinoid Pesticides

Abstract Neonicotinoid pesticide use has increased around the world despite accumulating evidence of their potential detrimental sub-lethal effects on the behaviour and physiology of bees, and its contribution to the global decline in bee health. Whilst flower colour is considered as one of the most important signals for foraging honey bees, the effects of pesticides on colour vision and memory retention remain unknown. We trained free flying foragers to an unscented artificial flower patch presenting yellow flower stimuli to investigate if sub-lethal levels of imidacloprid would disrupt the acquired association made between flower colour and food reward. We found that for concentrations higher than 4% of LD50 foraging honey bees no longer preferentially visited the yellow flowers and bees reverted back to baseline foraging preferences for blue flowers, with a complete loss of flower constancy. Higher pesticide dosages also resulted in a significant decrease in CaMKII and CREB gene expression, revealing a plausible mechanism to explain the disruption of bee foraging performance. Within important bee pollinators, colour vision is highly conserved and essential for efficient nutrition collection and survival. We thus show that to maintain efficient pollination services bees require environments free from neonicotinoid pesticides.

Effect of a colour dimorphism on the flower constancy of honey bees and bumble bees

2004 ◽  
Vol 82 (4) ◽  
pp. 587-593 ◽  
Author(s):  
Robert J Gegear ◽  
Terence M Laverty
Keyword(s):  
Honey Bees ◽  
Flower Colour ◽  
Bumble Bees ◽  
Bumble Bee ◽  
Flower Constancy ◽  
Flower Colours ◽  
High Degree ◽  
Flower Handling ◽  
The Relationship ◽  
Colour Dimorphism

We assessed the flower constancy of Italian honey bees (Apis mellifera ligustica Spinelli, 1808) and bumble bees (Bombus impatiens Cresson, 1863) by presenting individual foragers with a mixed array of equally rewarding yellow and blue flowers after they were trained to visit each colour in succession. All honey bees showed a high degree of flower constancy to one colour and rarely visited the alternate colour, whereas most bumble bees indiscriminately visited both colours. Foraging rates (flowers visited per minute) and flower handling times did not differ between honey bee and bumble bee foragers; however, bumble bees tended to fly farther between consecutive flower visits and make fewer moves to nearest neighbouring flowers than honey bees. When bees were forced to specialize on one of two previously rewarding flower colours by depleting one colour of reward, honey bees required almost twice as many flower visits to specialize on the rewarding flower colour as bumble bees. Together, these results suggest that the relationship between individual flower constancy and colour differences is not a general behavioural phenomenon in honey and bumble bees, perhaps because of differences in the ability of each group to effectively manage multiple colours at the same time and location.

scholarly journals Combined Toxicity of Insecticides and Fungicides Applied to California Almond Orchards to Honey Bee Larvae and Adults

Insects ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 20 ◽  
Author(s):  
Andrea Wade ◽  
Chia-Hua Lin ◽  
Colin Kurkul ◽  
Erzsébet Ravasz Regan ◽  
Reed M. Johnson
Keyword(s):  
Larval Development ◽  
Honey Bee ◽  
Honey Bees ◽  
Pesticide Exposure ◽  
Larval Mortality ◽  
Combined Toxicity ◽  
Pollination Services ◽  
Almond Orchards ◽  
Honey Bee Larvae

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.

scholarly journals Neonicotinoid pesticides and nutritional stress synergistically reduce survival in honey bees

2017 ◽  
Vol 284 (1869) ◽  
pp. 20171711 ◽  
Author(s):  
Simone Tosi ◽  
James C. Nieh ◽  
Fabio Sgolastra ◽  
Riccardo Cabbri ◽  
Piotr Medrzycki
Keyword(s):  
Food Consumption ◽  
Pesticide Exposure ◽  
Synergistic Effects ◽  
Nutritional Stress ◽  
Bee Health ◽  
Global Concern ◽  
Sugar Levels ◽  
Neonicotinoid Pesticides ◽  
Agricultural Areas ◽  
Poor Nutrition

The honey bee is a major pollinator whose health is of global concern. Declines in bee health are related to multiple factors, including resource quality and pesticide contamination. Intensive agricultural areas with crop monocultures potentially reduce the quality and quantity of available nutrients and expose bee foragers to pesticides. However, there is, to date, no evidence for synergistic effects between pesticides and nutritional stress in animals. The neonicotinoids clothianidin (CLO) and thiamethoxam (TMX) are common systemic pesticides that are used worldwide and found in nectar and pollen. We therefore tested if nutritional stress (limited access to nectar and access to nectar with low-sugar concentrations) and sublethal, field-realistic acute exposures to two neonicotinoids (CLO and TMX at 1/5 and 1/25 of LD 50 ) could alter bee survival, food consumption and haemolymph sugar levels. Bee survival was synergistically reduced by the combination of poor nutrition and pesticide exposure (−50%). Nutritional and pesticide stressors reduced also food consumption (−48%) and haemolymph levels of glucose (−60%) and trehalose (−27%). Our results provide the first demonstration that field-realistic nutritional stress and pesticide exposure can synergistically interact and cause significant harm to animal survival. These findings have implications for current pesticide risk assessment and pollinator protection.

scholarly journals Commoning the bloom? Rethinking bee forage management in industrial agriculture

Elem Sci Anth ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
J. L. Durant
Keyword(s):  
Honey Bees ◽  
Resource Sharing ◽  
Pesticide Exposure ◽  
Industrial Agriculture ◽  
Negative Effects ◽  
Bee Pollination ◽  
Pollination Services ◽  
Sustainable Food ◽  
Institutional Actors ◽  
Forage Management

Managed and wild bee populations are declining around the world, in part due to lost access to bee forage (i.e., nectar and pollen). As bee forage diminishes, the remaining acres become sites of contestation between beekeepers, land managers, ecologists, and regulatory agencies. This article applies a commons framing to contextualize these conflicts and attempts to resolve them. Drawing from the concepts of commons and commoning, I argue that nectar and pollen are common-pool resources for pollinators, beekeepers, and land managers, currently managed through varied access arrangements such as informal usufruct rights and pseudo-commoning practices. Like commoning, pseudo-commoning aims to collectively manage a resource through a set of protocols that involve equitable resource sharing and communication. However, because pseudo-commons are implemented from the top down, for example, from institutional actors driven in part by economic interests, they often do not result in widespread adoption on the ground. Through a case in California almond orchards, I make two additional arguments. First, because beekeepers are largely migratory and do not own the land they need for production, their subordinate position to landowners can challenge equitable bee forage management. Second, while floral pseudo-commons may aim to counter the negative effects of industrialized agricultural production (e.g., by limiting pesticide exposure to honey bees), they also provide a “fix” that supports and expands industrial agriculture by stabilizing managed bee pollination services. Increasing reliance on managed bee pollination services can thus disincentivize transitions to sustainable food production, such as adopting diversified practices that would support native bee populations and reduce the need for managed honey bees on farms.

scholarly journals Factors Affecting Immune Responses in Honey Bees: An Insight

2021 ◽  
Vol 65 (1) ◽  
pp. 25-47
Author(s):  
Gurleen Kaur ◽  
Rohit Sharma ◽  
Ashun Chaudhary ◽  
Randeep Singh
Keyword(s):  
Immune System ◽  
Honey Bees ◽  
Wild Plants ◽  
Modern World ◽  
Pollination Services ◽  
Colony Losses ◽  
Factors Affecting ◽  
Bee Health ◽  
Abundance And Diversity ◽  
The Cost

Abstract Honey bees pollinate various crops and wild plants which ensures food security. However, in this modern world, bees are suffering. Decreasing global domesticated and wild bee populations while the demand for agricultural pollination services is increasing is a matter of concern. Colony losses are driven by such factors or interactions as changing environmental conditions, exposure to agrochemicals, parasite and pathogens attack and decreased flower abundance and diversity. All these stresses individually or together affect the immune system of bees and consequently bee fitness. Poor nutrition is the key stressor as it directly suppresses the immune system and reduces host resistance to other stressors. To cope with these stresses, honey bees have well-developed individual and social immune systems which initiate several defence reactions, but its activation, maintenance and use are detrimental for bee survival as it occurs at the cost of bee health. This review summarizes the causal factors and their possible interaction responsible for immune suppression in honey bees.

scholarly journals Review on Sublethal Effects of Environmental Contaminants in Honey Bees (Apis mellifera), Knowledge Gaps and Future Perspectives

2021 ◽  
Vol 18 (4) ◽  
pp. 1863 ◽  
Author(s):  
Agata Di Noi ◽  
Silvia Casini ◽  
Tommaso Campani ◽  
Giampiero Cai ◽  
Ilaria Caliani
Keyword(s):  
Apis Mellifera ◽  
Honey Bees ◽  
Sublethal Effects ◽  
Integrated Approach ◽  
Anthropogenic Contamination ◽  
Knowledge Gaps ◽  
Pollination Services ◽  
General Decline ◽  
Polycyclic Aromatic ◽  
The Impact

Honey bees and the pollination services they provide are fundamental for agriculture and biodiversity. Agrochemical products and other classes of contaminants, such as trace elements and polycyclic aromatic hydrocarbons, contribute to the general decline of bees’ populations. For this reason, effects, and particularly sublethal effects of contaminants need to be investigated. We conducted a review of the existing literature regarding the type of effects evaluated in Apis mellifera, collecting information about regions, methodological approaches, the type of contaminants, and honey bees’ life stages. Europe and North America are the regions in which A. mellifera biological responses were mostly studied and the most investigated compounds are insecticides. A. mellifera was studied more in the laboratory than in field conditions. Through the observation of the different responses examined, we found that there were several knowledge gaps that should be addressed, particularly within enzymatic and molecular responses, such as those regarding the immune system and genotoxicity. The importance of developing an integrated approach that combines responses at different levels, from molecular to organism and population, needs to be highlighted in order to evaluate the impact of anthropogenic contamination on this pollinator species.

scholarly journals Impact of Chronic Exposure to Sublethal Doses of Glyphosate on Honey Bee Immunity, Gut Microbiota and Infection by Pathogens

2021 ◽  
Vol 9 (4) ◽  
pp. 845
Author(s):  
Loreley Castelli ◽  
Sofía Balbuena ◽  
Belén Branchiccela ◽  
Pablo Zunino ◽  
Joanito Liberti ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Honey Bee ◽  
Chronic Exposure ◽  
Pollination Services ◽  
Deformed Wing Virus ◽  
Immune Genes ◽  
Bee Health ◽  
Honey Bee Health ◽  
Sublethal Doses ◽  
The Impact

Glyphosate is the most used pesticide around the world. Although different studies have evidenced its negative effect on honey bees, including detrimental impacts on behavior, cognitive, sensory and developmental abilities, its use continues to grow. Recent studies have shown that it also alters the composition of the honey bee gut microbiota. In this study we explored the impact of chronic exposure to sublethal doses of glyphosate on the honey bee gut microbiota and its effects on the immune response, infection by Nosema ceranae and Deformed wing virus (DWV) and honey bee survival. Glyphosate combined with N. ceranae infection altered the structure and composition of the honey bee gut microbiota, for example by decreasing the relative abundance of the core members Snodgrassella alvi and Lactobacillus apis. Glyphosate increased the expression of some immune genes, possibly representing a physiological response to mitigate its negative effects. However, this response was not sufficient to maintain honey bee health, as glyphosate promoted the replication of DWV and decreased the expression of vitellogenin, which were accompanied by a reduced life span. Infection by N. ceranae also alters honey bee immunity although no synergistic effect with glyphosate was observed. These results corroborate previous findings suggesting deleterious effects of widespread use of glyphosate on honey bee health, and they contribute to elucidate the physiological mechanisms underlying a global decline of pollination services.

scholarly journals Propolis Extract and Chitosan Improve Health of Nosema ceranae Infected Giant Honey Bees, Apis dorsata Fabricius, 1793

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 785
Author(s):  
Sanchai Naree ◽  
Rujira Ponkit ◽  
Evada Chotiaroonrat ◽  
Christopher L. Mayack ◽  
Guntima Suwannapong
Keyword(s):  
Honey Bees ◽  
Treatment Options ◽  
Survival Rates ◽  
Nosema Ceranae ◽  
Apis Dorsata ◽  
Propolis Extract ◽  
Bee Health ◽  
Honey Bee Health ◽  
Underlying Mechanisms ◽  
Honey Solution

Nosema ceranae is a large contributing factor to the most recent decline in honey bee health worldwide. Developing new alternative treatments against N. ceranae is particularly pressing because there are few treatment options available and therefore the risk of increased antibiotic resistance is quite high. Recently, natural products have demonstrated to be a promising avenue for finding new effective treatments against N. ceranae. We evaluated the effects of propolis extract of stingless bee, Tetrigona apicalis and chito-oligosaccharide (COS) on giant honey bees, Apis dorsata, experimentally infected with N. ceranae to determine if these treatments could improve the health of the infected individuals. Newly emerged Nosema-free bees were individually inoculated with 106N. ceranae spores per bee. We fed infected and control bees the following treatments consisting of 0%, 50%, propolis extracts, 0 ppm and 0.5 ppm COS in honey solution (w/v). Propolis extracts and COS caused a significant increase in trehalose levels in hemolymph, protein contents, survival rates and acini diameters of the hypopharyngeal glands in infected bees. Our results suggest that propolis and COS could improve the health of infected bees. Further research is needed to determine the underlying mechanisms responsible for the improved health of the infected bees.

scholarly journals Nectar non-protein amino acids (NPAAs) do not change nectar palatability but enhance learning and memory in honey bees

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniele Carlesso ◽  
Stefania Smargiassi ◽  
Elisa Pasquini ◽  
Giacomo Bertelli ◽  
David Baracchi
Keyword(s):  
Amino Acids ◽  
Learning And Memory ◽  
Honey Bees ◽  
Feeding Preference ◽  
Memory Retention ◽  
Floral Nectar ◽  
Olfactory Conditioning ◽  
Specific Memory ◽  
Protein Amino Acids ◽  
Valuable Compounds

AbstractFloral nectar is a pivotal element of the intimate relationship between plants and pollinators. Nectars are composed of a plethora of nutritionally valuable compounds but also hundreds of secondary metabolites (SMs) whose function remains elusive. Here we performed a set of behavioural experiments to study whether five ubiquitous nectar non-protein amino acids (NPAAs: β-alanine, GABA, citrulline, ornithine and taurine) interact with gustation, feeding preference, and learning and memory in Apis mellifera. We showed that foragers were unable to discriminate NPAAs from water when only accessing antennal chemo-tactile information and that freely moving bees did not exhibit innate feeding preferences for NPAAs. Also, NPAAs did not alter food consumption or longevity in caged bees over 10 days. Taken together our data suggest that natural concentrations of NPAAs did not alter nectar palatability to bees. Olfactory conditioning assays showed that honey bees were more likely to learn a scent when it signalled a sucrose reward containing either β-alanine or GABA, and that GABA enhanced specific memory retention. Conversely, when ingested two hours prior to conditioning, GABA, β-alanine, and taurine weakened bees’ acquisition performances but not specific memory retention, which was enhanced in the case of β-alanine and taurine. Neither citrulline nor ornithine affected learning and memory. NPAAs in nectars may represent a cooperative strategy adopted by plants to attract beneficial pollinators.

scholarly journals Comparing Survival of Israeli Acute Paralysis Virus Infection among Stocks of U.S. Honey Bees

Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 60
Author(s):  
Shilpi Bhatia ◽  
Saman S. Baral ◽  
Carlos Vega Melendez ◽  
Esmaeil Amiri ◽  
Olav Rueppell
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Virus Infections ◽  
Israeli Acute Paralysis Virus ◽  
Immune Genes ◽  
Starting Point ◽  
Bee Health ◽  
Honey Bee Health ◽  
Survival Differences ◽  
Paralysis Virus

Among numerous viruses that infect honey bees (Apis mellifera), Israeli acute paralysis virus (IAPV) can be linked to severe honey bee health problems. Breeding for virus resistance may improve honey bee health. To evaluate the potential for this approach, we compared the survival of IAPV infection among stocks from the U.S. We complemented the survival analysis with a survey of existing viruses in these stocks and assessing constitutive and induced expression of immune genes. Worker offspring from selected queens in a common apiary were inoculated with IAPV by topical applications after emergence to assess subsequent survival. Differences among stocks were small compared to variation within stocks, indicating the potential for improving honey bee survival of virus infections in all stocks. A positive relation between worker survival and virus load among stocks further suggested that honey bees may be able to adapt to better cope with viruses, while our molecular studies indicate that toll-6 may be related to survival differences among virus-infected worker bees. Together, these findings highlight the importance of viruses in queen breeding operations and provide a promising starting point for the quest to improve honey bee health by selectively breeding stock to be better able to survive virus infections.

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