scholarly journals Bee-associated fungi mediate effects of fungicides on bumble bees

2021 ◽  
Author(s):  
Danielle Rutkowski ◽  
Eliza Litsey ◽  
Isabelle Maalouf ◽  
Rachel L Vannette

Bumble bees are important pollinators that face threats from multiple sources, including agrochemical application. Declining bumble bee populations have been linked to fungicide application, which could directly affect the fungi often found in the stored food and GI tract of healthy bumble bees. Here, we test the hypothesis that fungicides impact bee health by disrupting bee-fungi interactions. We examine the interactive effects of the fungicide propiconazole and fungal supplementation on the survival, reproduction, and microbiome composition of microcolonies (queenless colonies) using two species, Bombus vosnesenskii and B. impatiens. We found that both bee species benefitted from fungi, but were differentially affected by fungicides. In B. vosnesenskii, fungicide exposure decreased survival while fungal supplementation mitigated fungicide effects. For B. impatiens, fungicide application had no effect, but fungal supplementation improved survival and offspring production. Fungicides reduced fungal abundance in B. vosnesenskii microcolonies, but not in B. impatiens, where instead fungal addition decreased fungal abundance. In B. vosnesenskii, the abundance of the pathogen Ascosphaera was negatively associated with survival, while the yeast Zygosaccharomyces was positively associated with survival. Our results highlight species-specific differences in response to fungicides and the nature of bee-fungi associations, and caution the use of results obtained using one species to predict responses of other species. These results demonstrate that fungicides can alter bee-fungi interactions with consequences for bee survival and reproduction, and suggest that exploring the mechanisms of such interactions, including interactions among fungi in the bee GI tract, may offer insights into bumble bee biology and conservation strategies.

Amino Acids ◽  
2021 ◽  
Author(s):  
C. Ruth Archer ◽  
Johannes Fähnle ◽  
Maximilian Pretzner ◽  
Cansu Üstüner ◽  
Nina Weber ◽  
...  

AbstractThe ratio of amino acids to carbohydrates (AA:C) that bumble bees consume has been reported to affect their survival. However, it is unknown how dietary AA:C ratio affects other bumble bee fitness traits (e.g., fecundity, condition) and possible trade-offs between them. Moreover, while individual AAs affect phenotype in many species, the effects of AA blend on bumble bee fitness and food intake are unclear. We test how the AA:C ratio that bumble bees (Bombus terrestris) consume affects their condition (abdomen lipid and dry mass), survival following food removal, and ovarian activation. We then compare ovarian activation and food intake in bees fed identical AA:C ratios, but where the blend of AAs in diets differ, i.e., diets contained the same 10 AAs in an equimolar ratio or in the same ratio as in bee collected pollen. We found that AA:C ratio did not significantly affect survival following food removal or ovarian activation; however, high AA intake increased body mass, which is positively correlated with multiple fitness traits in bumble bees. AA blend (i.e., equimolar versus pollen) did not significantly affect overall ovarian activation or consumption of each experimental diet. However, there was an interaction between AA mix and dietary AA:C ratio affecting survival during the feeding experiment, and signs that there may have been weak, interactive effects of AA mix and AA:C ratio on food consumption. These results suggest that the effect of total AA intake on bumble bee phenotype may depend on the blend of individual AAs in experimental diets. We suggest that research exploring how AA blend affects bumble bee performance and dietary intake is warranted, and highlight that comparing research on bee nutrition is complicated by even subtle variation in experimental diet composition.


Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 421
Author(s):  
Amélie Gervais ◽  
Marc Bélisle ◽  
Marc J. Mazerolle ◽  
Valérie Fournier

Bumble bees are among the most effective pollinators in orchards during the blooming period, yet they are often threatened by the high levels of pesticide use in apple production. This study aimed to evaluate the influence of landscape enhancements (e.g., hedgerows, flower strips) on bumble bee queens in apple orchards. Bumble bee queens from 12 orchards in southern Québec (Canada) were marked, released, and recaptured in the springs and falls of 2017 to 2019. Half of the 12 orchards had landscape enhancements. Apples were harvested in 2018 and 2019 to compare their quality (weight, diameter, sugar level, and seed number) in sites with and without landscape enhancements. Species richness, as well as the occurrence of three species out of eight, was higher in orchards with landscape enhancements than in orchards without such structures. The occurrence of Bombus ternarius was lower in orchards with high levels of pesticide use. Apples had fewer seeds when collected in orchards with landscape enhancements and were heavier in orchards that used more pesticides. Our work provides additional evidence that landscape enhancements improve bumble bee presence in apple orchards and should therefore be considered as a means to enhance pollination within farms.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marcel Mertes ◽  
Julie Carcaud ◽  
Jean-Christophe Sandoz

AbstractSociality is classified as one of the major transitions in evolution, with the largest number of eusocial species found in the insect order Hymenoptera, including the Apini (honey bees) and the Bombini (bumble bees). Bumble bees and honey bees not only differ in their social organization and foraging strategies, but comparative analyses of their genomes demonstrated that bumble bees have a slightly less diverse family of olfactory receptors than honey bees, suggesting that their olfactory abilities have adapted to different social and/or ecological conditions. However, unfortunately, no precise comparison of olfactory coding has been performed so far between honey bees and bumble bees, and little is known about the rules underlying olfactory coding in the bumble bee brain. In this study, we used in vivo calcium imaging to study olfactory coding of a panel of floral odorants in the antennal lobe of the bumble bee Bombus terrestris. Our results show that odorants induce reproducible neuronal activity in the bumble bee antennal lobe. Each odorant evokes a different glomerular activity pattern revealing this molecule’s chemical structure, i.e. its carbon chain length and functional group. In addition, pairwise similarity among odor representations are conserved in bumble bees and honey bees. This study thus suggests that bumble bees, like honey bees, are equipped to respond to odorants according to their chemical features.


2018 ◽  
Vol 23 (6/7) ◽  
pp. 576-594 ◽  
Author(s):  
Samantha L. Jordan ◽  
Wayne A. Hochwarter ◽  
Gerald R. Ferris ◽  
Aqsa Ejaz

Purpose The purpose of this paper is to test the interactive effects of grit (e.g. supervisor and employee) and politics perceptions on relevant work outcomes. Specifically, the authors hypothesized that supervisor and employee grit would each demonstrate neutralizing effects when examined jointly. Design/methodology/approach Three studies (N’s=526, 229, 522) were conducted to test the moderating effect across outcomes, including job satisfaction, turnover intentions, citizenship behavior and work effort. The authors controlled for affectivity and nonlinear main effect terms in Studies 2 and 3 following prior discussion. Findings Findings across studies demonstrated a unique pattern differentiating between grit sources (i.e. employee vs supervisor) and outcome characteristic (i.e. attitudinal vs behavioral). In sum, both employee and supervisor grit demonstrated neutralizing effects when operating in politically fraught work settings. Research limitations/implications Despite the single source nature of data collections, the authors took steps to minimize potential biasing factors (e.g. time separation, including affectivity). Future research will benefit from multiple sources of data as well as a more expansive view of the grit construct. Practical implications Work contexts have grown increasingly more political in recent years primarily as a result of social and motivational factors. Hence, the authors recommend that leaders investigate factors that minimize its potentially malignant effects. Although grit is often challenging to cultivate through interventions, selection and quality of work life programs may be useful in preparing workers to manage this pervasive source of stress. Originality/value Despite its practical appeal, grit’s impact in work settings has been under-studied, leading to apparent gaps in science and leadership development. Creative studies, building off the research, will allow grit to maximize its contributions to both scholarship and employee well-being.


2020 ◽  
Vol 113 (3) ◽  
pp. 1055-1061 ◽  
Author(s):  
Laura Šimenc ◽  
Urška Kuhar ◽  
Urška Jamnikar-Ciglenečki ◽  
Ivan Toplak

Abstract The complete genome of Lake Sinai virus 3 (LSV3) was sequenced by the Ion Torrent next-generation sequencing (NGS) technology from an archive sample of honey bees collected in 2010. This strain M92/2010 is the first complete genome sequence of LSV lineage 3. From October 2016 to December 2017, 56 honey bee samples from 32 different locations and 41 bumble bee samples from five different locations were collected. These samples were tested using a specific reverse transcriptase-polymerase chain reaction (RT-PCR) method; 75.92% of honey bee samples and 17.07% of bumble bee samples were LSV-positive with the RT-PCR method. Phylogenetic comparison of 557-base pair-long RNA-dependent RNA polymerase (RdRp) genome region of selected 23 positive samples of honey bees and three positive bumble bee samples identified three different LSV lineages: LSV1, LSV2, and LSV3. The LSV3 lineage was confirmed for the first time in Slovenia in 2010, and the same strain was later detected in several locations within the country. The LSV strains detected in bumble bees are from 98.6 to 99.4% identical to LSV strains detected among honey bees in the same territory.


2019 ◽  
Vol 113 (2) ◽  
pp. 575-581 ◽  
Author(s):  
Jessica L Mullins ◽  
James P Strange ◽  
Amber D Tripodi

Abstract Bumble bees (Bombus [Hymenoptera: Apidae]) are important pollinators for agricultural crops, which has led to their commercial domestication. Despite their importance, little is known about the reproductive biology of bumble bees native to North America. The Hunt bumble bee (Bombus huntii Greene [Hymenoptera: Apidae]) and the Vosnesensky bumble bee (Bombus vosnesenskii Radoszkowski [Hymenoptera: Apidae] are native candidates for commercial production in western North America due to their efficacy in providing commercial pollination services. Availability of pollinators native to the region in which services would be provided would minimize the likelihood of introducing exotic species and spreading novel disease. Some parasites are known to affect bumble bee reproduction, but little is known about their prevalence in North America or how they affect queen success. Only 38% of wild-caught B. huntii and 51% wild-caught B. vosnesenskii queens collected between 2015 and 2017 initiated nests in the laboratory. Our objective was to identify causal factors leading to a queen’s inability to oviposit. To address this, we dissected each broodless queen and diagnosed diseases, assessed mating status, and characterized ovary development. Nematodes, arthropods, and microorganisms were detected in both species. Overall, 20% of queens were infected by parasites, with higher rates in B. vosnesenskii. Over 95% of both species were mated, and over 88% had developed ovaries. This suggests that parasitism and mating status were not primary causes of broodlessness. Although some failure to nest can be attributed to assessed factors, additional research is needed to fully understand the challenges presented by captive rearing.


2011 ◽  
Vol 279 (1730) ◽  
pp. 910-915 ◽  
Author(s):  
Olof Liberg ◽  
Guillaume Chapron ◽  
Petter Wabakken ◽  
Hans Christian Pedersen ◽  
N. Thompson Hobbs ◽  
...  

Poaching is a widespread and well-appreciated problem for the conservation of many threatened species. Because poaching is illegal, there is strong incentive for poachers to conceal their activities, and consequently, little data on the effects of poaching on population dynamics are available. Quantifying poaching mortality should be a required knowledge when developing conservation plans for endangered species but is hampered by methodological challenges. We show that rigorous estimates of the effects of poaching relative to other sources of mortality can be obtained with a hierarchical state–space model combined with multiple sources of data. Using the Scandinavian wolf ( Canis lupus ) population as an illustrative example, we show that poaching accounted for approximately half of total mortality and more than two-thirds of total poaching remained undetected by conventional methods, a source of mortality we term as ‘cryptic poaching’. Our simulations suggest that without poaching during the past decade, the population would have been almost four times as large in 2009. Such a severe impact of poaching on population recovery may be widespread among large carnivores. We believe that conservation strategies for large carnivores considering only observed data may not be adequate and should be revised by including and quantifying cryptic poaching.


2017 ◽  
Vol 16 (2) ◽  
pp. 148-159 ◽  
Author(s):  
Fikile Nxumalo

This article examines children’s encounters with dead and dying bumble bees in their everyday entangled lives. Within the context of an early childhood classroom located in suburban British Columbia, Canada, the article stories situated and emergent bee–child worldings to illustrate possibilities for learning with other species in anthropogenically damaged worlds. I pay attention to some of the ways in which children’s and educators’ practices have shifted away from encountering bees predominantly as objects of scientific knowledge towards more relational, embodied, and affective immersion in the lives and deaths of bumble bees. Situating these practices within current bumble bee vulnerabilities, I consider how children’s and educators’ inquiries might be viewed as pedagogies that matter for learning to live less destructively with others in current times of anthropogenic change.


1987 ◽  
Vol 65 (9) ◽  
pp. 2168-2176 ◽  
Author(s):  
K. W. Richards

Diversity, density, efficiency, and effectiveness of pollinators of cicer milkvetch, Astragalus cicer L., grown at two locations in southern Alberta were studied from 1978 to 1983. Twenty-seven species of bees were identified as pollinators. At Lethbridge, honey bees (Apis mellifera) comprised 74% of the observations, bumble bees 16%, and leafcutter bees 10%, while at Spring Coulee, the proportions were honey bees 14%, bumble bees 69%, and leafcutter bees 17%. The rate of foraging by pollinator species from flower to flower varied; bumble bee species, especially Bombus nevadensis Cress., foraged consistently more efficiently than honey bees or alfalfa leafcutter bees, Megachile rotundata (F.). A theoretical approach used to predict the bee populations required to pollinate varying flower densities shows that the population of B. nevadensis required is about half those of Bombus huntii Greene and M. rotundata and less than one-quarter that of the honey bee. Pollination by B. nevadensis consistently resulted in more seeds per pod than with any other bumble bee species, the honey bee, or M. rotundata. Of the nine species of bumble bee that established colonies in artificial domiciles near the field, B. nevadensis established the most colonies each year. The number of workers and sexuals produced per colony varied considerably among bumble bee species with only 55% of the colony establishments producing workers and 31% producing sexuals. The propagation rate and quality of alfalfa leafcutter bees produced on cicer milkvetch was excellent.


1979 ◽  
Vol 57 (10) ◽  
pp. 1866-1870 ◽  
Author(s):  
L. K. Hartling ◽  
R. C. Plowright

A remotely controlled artificial flower system for investigation of bumble bee foraging behaviour in the laboratory is described. The behaviour of Bombus atratus Fkln. workers from captive colonies trained to forage on patches of artificial flowers in a flight room conformed well to the predictions of optimal foraging theory. Within-patch movement was systematic, tending to minimize repeat visits to flowers sampled previously. Between-patch movement was influenced both by frequency of encounters with empty flowers in the first patch and by inter-patch distance.


Sign in / Sign up

Export Citation Format

Share Document