Factors influencing Nosema bombi infections in natural populations of Bombus terrestris (Hymenoptera: Apidae)

2012 ◽  
Vol 110 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Anett Huth-Schwarz ◽  
Josef Settele ◽  
Robin F.A. Moritz ◽  
F. Bernhard Kraus
Keyword(s):  
Bombus Terrestris ◽  
Natural Populations ◽  
Factors Influencing ◽  
Nosema Bombi

Horizontal transmission success of Nosema bombi to its adult bumble bee hosts: effects of dosage, spore source and host age

Parasitology ◽  
2007 ◽  
Vol 134 (12) ◽  
pp. 1719-1726 ◽  
Author(s):  
S. T. RUTRECHT ◽  
J. KLEE ◽  
M. J. F. BROWN
Keyword(s):  
Bombus Terrestris ◽  
Horizontal Transmission ◽  
Fold Increase ◽  
Population Heterogeneity ◽  
Host Susceptibility ◽  
Bumble Bee ◽  
Host Age ◽  
Transmission Success ◽  
Nosema Bombi ◽  
Evolutionary Epidemiology

SUMMARYParasite transmission dynamics are fundamental to explaining the evolutionary epidemiology of disease because transmission and virulence are tightly linked. Horizontal transmission of microsporidian parasites, e.g. Nosema bombi, may be influenced by numerous factors, including inoculation dose, host susceptibility and host population heterogeneity. Despite previous studies of N. bombi and its bumble bee hosts, neither the epidemiology nor impact of the parasite are as yet understood. Here we investigate the influence N. bombi spore dosage (1000 to 500 000 spores), spore source (Bombus terrestris and B. lucorum isolates) and host age (2- and 10-day-old bees) have on disease establishment and the presence of patent infections in adult bumble bees. Two-day-old bees were twice as susceptible as their 10-day-old sisters, and a 5-fold increase in dosage from 100 000 to 500 000 spores resulted in a 20-fold increase in the prevalence of patent infections. While intraspecific inoculations were 3 times more likely to result in non-patent infections there was no such effect on the development of patent infections. These results suggest that host-age and dose are likely to play a role in N. bombi's evolutionary epidemiology. The relatively low levels of horizontal transmission success are suggestive of low virulence in this system.

scholarly journals FACTORS INFLUENCING THE EFFECT OF SEGREGATION DISTORTION IN NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER

Genetics ◽  
1984 ◽  
Vol 107 (3) ◽  
pp. 375-393
Author(s):  
Rayla Greenberg Temin ◽  
Marta Marthas
Keyword(s):  
Segregation Distortion ◽  
Pericentric Inversion ◽  
Natural Populations ◽  
Special Test ◽  
Recessive Lethal ◽  
Factors Influencing ◽  
Direct Measurements ◽  
Tight Linkage ◽  
In The Wild

ABSTRACT The major components of the SD system have been examined in two natural populations of D. melanogaster to investigate how SD behaves and is maintained in nature and to estimate its impact and efficiency. A twofold approach was used: (1) direct measurements of segregation distortion in wild males and (2) measurement of sensitivity of wild SD  + chromosomes to SD action. Characterization of newly isolated SD chromosomes and of a large number of SD  + chromosomes from nature demonstrated that (1) SD can operate efficiently in the wild genome: 45% of SD/SD  + males collected from nature had k values larger than 0.70. (2) Forty-three of 44 newly recovered SD chromosomes are of the SD-72 type, having a small pericentric inversion that maintains tight linkage among the Sd, E(SD) and Rsp loci in the SD complex. In 1956, most SD chromosomes in Madison lacked this inversion. (3) Only 12 of the 44 SD chromosomes carried a recessive lethal (compared with five of six in 1956), and many of the viable SD chromosomes were fertile as homozygotes, indicating that SD homozygotes need not have obvious reductions in fitness. (4) Among more than 500 wild chromosomes assayed for response to distortion by a strong SD, at least 40-50% were sensitive, about 33% were partially sensitive and 17% were insensitive. This frequency of sensitives is higher than in reports from some other populations. An estimated 12% of the wild chromosomes were classified as true Rspi by their constellation of effects, including a special test of ability to cause self-distortion of a "suicide" chromosome, R(cn)-10. In a direct assay with R(cn)-10, an independent sample of 99 chromosomes from nature gave 30% putative Rspi. Thus, these populations contain in the range of 12-30% Rspi. (5) Chromosomes supersensitive to SD, previously described for certain laboratory stocks, were also found to coexist in nature with SD. (6) Profiles of wild chromosomes with a panel of three or four different SD testers suggest a series of allelic alternatives at the Rsp locus including supersensitive, sensitive, semisensitive and insensitive, and that loci other than Rsp may also be important in determining the effect of SD in nature.

Factors influencing the egg laying of workers in a captive Bombus terrestris colony

1981 ◽  
Vol 9 (1) ◽  
pp. 9-14 ◽  
Author(s):  
C. G. J. van Honk ◽  
P. -F. Röseler ◽  
H. H. W. Velthuis ◽  
J. C. Hoogeveen
Keyword(s):  
Bombus Terrestris ◽  
Egg Laying ◽  
Factors Influencing

scholarly journals Genetic Relationships Between Commercially Produced and Natural Populations of Bombus Terrestris Dalmatinus in Terms of Mitochondrial COI and CytB

2021 ◽  
Vol 65 (2) ◽  
pp. 315-330
Author(s):  
Kemal Karabağ ◽  
Emel Tüten Sevim ◽  
Şadiye Taşbaş
Keyword(s):  
High Frequency ◽  
Bombus Terrestris ◽  
Genetic Relationships ◽  
Natural Populations ◽  
Genetic Variations ◽  
Commercial Production ◽  
Bumble Bees ◽  
Natural Habitats ◽  
Mitochondrial Coi ◽  
Different Populations

Abstract Bombus terrestris dalmatinus is naturally common in many countries, including Turkey, and is also used commercially for the pollination of greenhouse plants. Intensive commercial production and international trade in many countries are considered as reasons for the disappearance of some natural populations. Hybridization of native bumble bees with those produced commercially, but having escaped from greenhouses and colonization of these commercial bees in natural habitats are cause for concern. In order to assess this concern, B. t. dalmatinus workers were collected from twelve different populations: five commercial producers, three surrounding greenhouse centers, three natural areas at least 30 km away from greenhouses, and one more recent greenhouse zone in Antalya, Turkey. The genetic variations and relationships among the twelve populations were estimated using SNP haplotypes determined in mitochondrial COI and CytB. Twenty and sixteen haplotypes were obtained for COI and CytB, respectively. A single haplotype, H1, was widespread with a high frequency in all individuals for both genes. Individuals collected from around greenhouse centers and commercial companies had more common haplotypes. The genetic variations of intra-populations were higher than the interpopulations in both COI (65.41%>34.59%) and CytB (72.47%>27.53%). The natural and commercial populations were genetically more distant from each other considering Fst values. However, samples from near the greenhouses had a higher similarity with the commercially produced samples, while the natural populations far away from greenhouses still retained their genetic distinctiveness.

scholarly journals Individual and combined impacts of sulfoxaflor and Nosema bombi on bumblebee ( Bombus terrestris ) larval growth

2020 ◽  
Vol 287 (1932) ◽  
pp. 20200935 ◽  
Author(s):  
Harry Siviter ◽  
Arran J. Folly ◽  
Mark J. F. Brown ◽  
Ellouise Leadbeater
Keyword(s):  
Reproductive Output ◽  
Bombus Terrestris ◽  
Larval Mortality ◽  
Larval Growth ◽  
Life History Stage ◽  
Nosema Bombi ◽  
Negative Effect ◽  
Negative Impacts ◽  
The Individual ◽  
The Impact

Sulfoxaflor is a globally important novel insecticide that can have negative impacts on the reproductive output of bumblebee ( Bombus terrestris ) colonies. However, it remains unclear as to which life-history stage is critically affected by exposure. One hypothesis is that sulfoxaflor exposure early in the colony's life cycle can impair larval development, reducing the number of workers produced and ultimately lowering colony reproductive output. Here we assess the influence of sulfoxaflor exposure on bumblebee larval mortality and growth both when tested in insolation and when in combination with the common fungal parasite Nosema bombi, following a pre-registered design. We found no significant impact of sulfoxaflor (5 ppb) or N. bombi exposure (50 000 spores) on larval mortality when tested in isolation but found an additive, negative effect when larvae received both stressors in combination. Individually, sulfoxaflor and N. bombi exposure each impaired larval growth, although the impact of combined exposure fell significantly short of the predicted sum of the individual effects (i.e. they interacted antagonistically). Ultimately, our results suggest that colony-level consequences of sulfoxaflor exposure for bumblebees may be mediated through direct effects on larvae. As sulfoxaflor is licensed for use globally, our findings highlight the need to understand how novel insecticides impact non-target insects at various stages of their development.

Population Dynamics of the Wolbachia Infection Causing Cytoplasmic Incompatibility in Drosophila melanogaster

Genetics ◽  
1998 ◽  
Vol 148 (1) ◽  
pp. 221-231 ◽  
Author(s):  
Ary A Hoffmann ◽  
Miriam Hercus ◽  
Hayat Dagher
Keyword(s):  
Population Dynamics ◽  
Drosophila Melanogaster ◽  
Cytoplasmic Incompatibility ◽  
Larval Density ◽  
Natural Populations ◽  
Wolbachia Infection ◽  
Field Conditions ◽  
Exact Nature ◽  
Infection Status ◽  
Factors Influencing

Abstract Field populations of Drosophila melanogaster are often infected with Wolbachia, a vertically transmitted microorganism. Under laboratory conditions the infection causes partial incompatibility in crosses between infected males and uninfected females. Here we examine factors influencing the distribution of the infection in natural populations. We show that the level of incompatibility under field conditions was much weaker than in the laboratory. The infection was not transmitted with complete fidelity under field conditions, while field males did not transmit the infection to uninfected females and Wolbachia did not influence sperm competition. There was no association between field fitness as measured by fluctuating asymmetry and the infection status of adults. Infected field females were smaller than uninfecteds in some collections from a subtropical location, but not in other collections from the same location. Laboratory cage studies showed that the infection did not change in frequency when populations were maintained at a low larval density, but it decreased in frequency at a high larval density. Monitoring of infection frequencies in natural populations indicated stable frequencies in some populations but marked fluctuations in others. Simple models suggest that the infection probably provides a fitness benefit for the host in order to persist in populations. The exact nature of this benefit remains elusive.

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