scholarly journals Local bumble bee decline linked to recovery of honey bees, drought effects on floral resources

2016 ◽  
Vol 19 (10) ◽  
pp. 1247-1255 ◽  
Author(s):  
Diane M. Thomson
2021 ◽  
Vol 27 ◽  
Author(s):  
Diane M Thomson

Growing evidence supports that many bee populations are declining, with potentially serious consequences for pollination services. Mechanistic models that predict bee abundances from drivers like floral resource availability can be a powerful way to understand and address declines, but remain rare and largely unvalidated. I used temporally and spatially novel data to validate previous analyses linking bumble bee (Bombus spp.) declines in California coastal scrub with loss of floral resources, mediated by drought and competition with non-native honey bees (Apis mellifera). New observations from 2015-2018 were combined with data from 1999-2014 to further test these mechanistic hypotheses and evaluate predictions of a statistical model for Bombus abundances. As predicted, positive associations between spring rainfall and floral abundances and between Bombus and key forage plants were consistent between time periods. Increased A. mellifera abundance corresponded with reduced Bombus use of the most abundant forage plant and lower Bombus abundances in the following year. Quantitative predictions from the Bombus statistical model previously developed for 1999-2014 were relatively unbiased and strongly rank correlated with either spatially or temporally novel data. However, the model consistently underpredicted Bombus abundances when both flower patch and time period were novel. Overall, four new years of data further strengthen evidence that loss of floral resources due to drought and competition with feral Apis mellifera is an important cause of Bombus decline in this habitat. These findings reinforce the value of even simple models that are mechanistically framed, both in understanding past patterns of change and for qualitative prediction. 


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.


2017 ◽  
Vol 12 ◽  
pp. 47 ◽  
Author(s):  
Andreas Thrasyvoulou ◽  
Basilis Tsirakoglou

Three consecutive sowings of Phacelia tanacetifolia Bentham (Hydrophyllaceae) were examined for plant growth and attractiveness to bees and other insect-visitors over a three years’ study. Plants that were sown in March flowered uniformly for periods of 24 to 40 days, while those sown in June and July had a non-uniform anthesis that was impossible to estimate. Plants sown in early August, remained vegetative throughout winter and flowered the following spring. Maximum visits of honey bees were observed between 10:00 h and 17:00 h. Most honey bees (>70%) collected nectar. Seasonal differences in the ratio nectar/pollen gatherers were noted. Two species of bumble bee (B. terrestris and B. lucorum) and 9 species of solitary bee visited Phacelia.


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.


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.


2020 ◽  
Vol 10 (13) ◽  
pp. 6741-6751 ◽  
Author(s):  
Christine Urbanowicz ◽  
Paige A. Muñiz ◽  
Scott H. McArt
Keyword(s):  

2020 ◽  
Vol 49 (3) ◽  
pp. 753-764 ◽  
Author(s):  
Ashley L St. Clair ◽  
Ge Zhang ◽  
Adam G Dolezal ◽  
Matthew E O’Neal ◽  
Amy L Toth

Abstract In the last century, a global transformation of Earth’s surface has occurred due to human activity with extensive agriculture replacing natural ecosystems. Concomitant declines in wild and managed bees are occurring, largely due to a lack of floral resources and inadequate nutrition, caused by conversion to monoculture-based farming. Diversified fruit and vegetable farms may provide an enhanced variety of resources through crops and weedy plants, which have potential to sustain human and bee nutrition. We hypothesized fruit and vegetable farms can enhance honey bee (Hymenoptera: Apidae, Apis mellifera Linnaeus) colony growth and nutritional state over a soybean monoculture, as well as support a more diverse wild bee community. We tracked honey bee colony growth, nutritional state, and wild bee abundance, richness, and diversity in both farm types. Honey bees kept at diversified farms had increased colony weight and preoverwintering nutritional state. Regardless of colony location, precipitous declines in colony weight occurred during autumn and thus colonies were not completely buffered from the stressors of living in a matrix dominated with monocultures. Contrary to our hypothesis, wild bee diversity was greater in soybean, specifically in August, a time when fields are in bloom. These differences were largely driven by four common bee species that performed well in soybean. Overall, these results suggest fruit and vegetable farms provide some benefits for honey bees; however, they do not benefit wild bee communities. Thus, incorporation of natural habitat, rather than diversified farming, in these landscapes, may be a better choice for wild bee conservation efforts.


2016 ◽  
Vol 60 (2) ◽  
pp. 179-192 ◽  
Author(s):  
Anna Wróblewska ◽  
Ernest Stawiarz ◽  
Marzena Masierowska

Abstract Offering more floral resources for urban bees can be achieved by growing ornamental bee plants. The aim of the present study was to evaluate selected Asteraceae (Calendula officinalis ‘Persimmon Beauty’ and ‘Santana’, Centaurea macrocephala, Cosmos sulphureus, Dahlia pinnata, Tagetes patula, Tithonia rotundifolia, and Zinnia elegans) as pollen sources for pollinators. Under urban conditions in Lublin, SE Poland, the investigated plants flowered from late June to the end of October. The mass of pollen produced in florets and capitula was found to be species-related. The highest pollen amounts per 10 florets (10.1 mg) as well as per capitulum (249.7 mg) were found for C. macrocephala. The mass of pollen yielded by a single plant depended on both the pollen mass delivered per disk florets and the proportion of disk florets in capitulum, and the flowering abundance of the plants. A single plant of D. pinnata and a single plant of T. rotundifolia each produced the largest pollen mass. Mean pollen yield per 1m2 of a plot ranged from 6.2 g (Z. elegans) to 60.7 g (D. pinnata). Pollen grains are tricolporate, with echinate exine, medium or small in size. They can be categorised as oblatespherical, spherical, and prolatespherical. The principal visitors to C. macrocephala, C. sulphureus, and C. officinalis were honey bees, whereas bumble bees dominated on T. rotundifolia and D. pinnata. A magnet plant for butterflies was Z. elegans. Among the investigated species, D. pinnata, C. macrocephala, and T. rotundifolia were found to be the most valuable sources of pollen flow for managed and wild bees.


Sign in / Sign up

Export Citation Format

Share Document