Shift in virus composition in honeybees () following worldwide invasion by the parasitic mite and virus vector .

Invasive vectors can induce dramatic changes in disease epidemiology. While viral emergence following geographical range expansion of a vector is well known, the influence a vector can have at the level of the host's pathobiome is less well understood. Taking advantage of the formerly heterogeneous spatial distribution of the ectoparasitic mite that acts as potent virus vector among honeybees , we investigated the impact of its recent global spread on the viral community of honeybees in a retrospective study of historical samples.

Virus infections in honeybee colonies naturally surviving ectoparasitic mite vectors.

Western honeybee populations, Apis mellifera, in Europe have been known to survive infestations of the ectoparasitic mite, Varroa destructor, by means of natural selection. Proposed mechanisms in literature have been focused on the management of this parasite, however literature remains scare on the differences in viral ecology between colonies that have adapted to V. destructor and those that are consistently treated for it.

Host brood traits, independent of adult behaviours, reduce Varroa destructor mite reproduction in resistant honeybee populations.

The ectoparasitic mite Varroa destructor is an invasive species of Western honey bees (Apis mellifera) and the largest pathogenic threat to their health world-wide. Its successful invasion and expansion is related to its ability to exploit the worker brood for reproduction, which results in an exponential population growth rate in the new host. With invasion of the mite, wild honeybee populations have been nearly eradicated from Europe and North America, and the survival of managed honeybee populations relies on mite population control treatments.

Cutting corners: The impact of storage and DNA extraction on quality and quantity of DNA in honeybee () spermatheca.

The purpose of our study was to investigate methods of short-term storage that allow preservation, transport and retrieval of genetic information contained in honeybee queen's spermatheca. Genotyping of the honeybee colony requires well ahead planned sample collection, depending on the type of data to be acquired. Sampling and genotyping of spermatheca's content instead of individual offspring is timesaving, allowing answers to the questions related to patriline composition immediately after mating.

Virus Prevalence in Egg Samples Collected from Naturally Selected and Traditionally Managed Honey Bee Colonies across Europe.

Monitoring virus infections can be an important selection tool in honey bee breeding. A recent study pointed towards an association between the virus-free status of eggs and an increased virus resistance to deformed wing virus (DWV) at the colony level. In this study, eggs from both naturally surviving and traditionally managed colonies from across Europe were screened for the prevalence of different viruses.

Identification of 121 variants of honey bee Vitellogenin protein sequences with structural differences at functional sites.

Proteins are under selection to maintain central functions and to accommodate needs that arise in ever-changing environments. The positive selection and neutral drift that preserve functions result in a diversity of protein variants. The amount of diversity differs between proteins: multifunctional or disease-related proteins tend to have fewer variants than proteins involved in some aspects of immunity.

CSI Pollen: Diversity of Honey Bee Collected Pollen Studied by Citizen Scientists.

A diverse supply of pollen is an important factor for honey bee health, but information about the pollen diversity available to colonies at the landscape scale is largely missing. In this COLOSS study, beekeeper citizen scientists sampled and analyzed the diversity of pollen collected by honey bee colonies. As a simple measure of diversity, beekeepers determined the number of colors found in pollen samples that were collected in a coordinated and standardized way.

Adaptive population structure shifts in invasive parasitic mites, .

Comparative studies of genetic diversity and population structure can shed light on the ecological and evolutionary factors governing host-parasite interactions. Even though invasive parasites are considered of major biological importance, little is known about their adaptative potential when infesting the new hosts. Here, the genetic diversification of , a novel parasite of originating from Asia, was investigated using population genetics to determine how the genetic structure of the parasite changed in distinct European populations of its new host.

Adapted tolerance to virus infections in four geographically distinct Varroa destructor-resistant honeybee populations.

The ectoparasitic mite, Varroa destructor, is unarguably the leading cause of honeybee (Apis mellifera) mortality worldwide through its role as a vector for lethal viruses, in particular, strains of the Deformed wing virus (DWV) and Acute bee paralysis virus (ABPV) complexes. Several honeybee populations across Europe have well-documented adaptations of mite-resistant traits but little is known about host adaptations towards the virus infections vectored by the mite. The aim of this study was to assess and compare the possible contribution of adapted virus tolerance and/or resistance to the enhanced survival of four well-documented mite-resistant honeybee populations from Norway, Sweden, The Netherlands and France, in relation to unselected mite-susceptible honeybees.

Reproductive success of the parasitic mite (Varroa destructor) is lower in honeybee colonies that target infested cells with recapping.

Cell recapping is a behavioural trait of honeybees (Apis mellifera) where cells with developing pupae are uncapped, inspected, and then recapped, without removing the pupae. The ectoparasitic mite Varroa destructor, unarguably the most destructive pest in apiculture world-wide, invades the cells of developing pupae to feed and reproduce. Honeybees that target mite infested cells with this behaviour may disrupt the reproductive cycle of the mite.

Evaluation of Suppressed Mite Reproduction (SMR) Reveals Potential for Varroa Resistance in European Honey Bees ( L.).

In the fight against the mite, selective breeding of honey bee ( L.) populations that are resistant to the parasitic mite stands as a sustainable solution. Selection initiatives indicate that using the suppressed mite reproduction (SMR) trait as a selection criterion is a suitable tool to breed such resistant bee populations.

Honey bee predisposition of resistance to ubiquitous mite infestations.

Host-parasite co-evolution history is lacking when parasites switch to novel hosts. This was the case for Western honey bees (Apis mellifera) when the ectoparasitic mite, Varroa destructor, switched hosts from Eastern honey bees (Apis cerana). This mite has since become the most severe biological threat to A.

Reduced Postcapping Period in Honey Bees Surviving by Means of Natural Selection.

The ectoparasitic mite is a key factor for colony losses in European honey bee subspecies (), but it is also known that some host populations have adapted to the mite by means of natural selection. The role of a shorter host brood postcapping period in reducing mite reproductive success has been investigated in other surviving subspecies, however its role in the adaptation of European honey bee populations has not been addressed. Here, we use a common garden approach to compare the length of the worker brood postcapping period in a Norwegian surviving honey bee population with the postcapping period of a local susceptible population.

Rapid parallel evolution overcomes global honey bee parasite.

In eusocial insect colonies nestmates cooperate to combat parasites, a trait called social immunity. However, social immunity failed for Western honey bees (Apis mellifera) when the ectoparasitic mite Varroa destructor switched hosts from Eastern honey bees (Apis cerana). This mite has since become the most severe threat to A.

Molecular methods indicate lack of spread of Acarapis woodi introduced to honey bees in western Norway.

The tracheal mite, Acarapis woodi, may be one of many factors contributing to the decline in honey bee (Apis mellifera) populations. Databases on the widespread distribution of A. woodi exist, but the data seem patchy.

Norwegian honey bees surviving mite infestations by means of natural selection.

Background: Managed, feral and wild populations of European honey bee subspecies, , are currently facing severe colony losses globally. There is consensus that the ectoparasitic mite , that switched hosts from the Eastern honey bee to the Western honey bee , is a key factor driving these losses. For >20 years, breeding efforts have not produced European honey bee colonies that can survive infestations without the need for mite control.

A worldwide survey of genome sequence variation provides insight into the evolutionary history of the honeybee Apis mellifera.

The honeybee Apis mellifera has major ecological and economic importance. We analyze patterns of genetic variation at 8.3 million SNPs, identified by sequencing 140 honeybee genomes from a worldwide sample of 14 populations at a combined total depth of 634×.

The effects of primiparity on reproductive performance in the brown bear.

We studied the effects of primiparity on litter size, offspring size, and cub loss in brown bears (Ursus arctos) in two study areas (north, south) in Sweden from 1987 to 2006. Sexually selected infanticide (SSI) has been suggested previously as a mortality factor in our study populations. Females in the south became primiparous earlier than females in the north.

Seasonal range size in relation to reproductive strategies in brown bears Ursus arctos.

Data on seasonal ranges of 93 radio-collared adult brown bears (Ursus arctos) were used to test hypotheses explaining variation in range size in relation to male and female reproductive strategies. Both males and oestrous females used large ranges in the mating season, but decreased their ranges after the mating season. These results suggested that both sexes in this species roam to mate, because the results could not be explained by a seasonal change in food availability nor by increased foraging movements of oestrous females to replenish body reserves after previous cub raising.