The impact of mass-flowering crops on bee pathogen dynamics.

Nearly two fifths of the Earth's land area is currently used for agriculture, substantially impacting the environment and ecosystems. Besides the direct impact through land use change, intensive agriculture can also have an indirect impact, for example by changing wildlife epidemiology. We review here the potential effects of mass-flowering crops (MFCs), which are rapidly expanding in global cropping area, on the epidemiology of known pathogens in bee pollinators.

Critical View on the Importance of Host Defense Strategies on Virus Distribution of Bee Viruses: What Can We Learn from SARS-CoV-2 Variants?

Bees, both wild and domesticated ones, are hosts to a plethora of viruses, with most of them infecting a wide range of bee species and genera. Although viral discovery and research on bee viruses date back over 50 years, the last decade is marked by a surge of new studies, new virus discoveries, and reports on viral transmission in and between bee species. This steep increase in research on bee viruses was mainly initiated by the global reports on honeybee colony losses and the worldwide wild bee decline, where viruses are regarded as one of the main drivers.

Honey bees and climate explain viral prevalence in wild bee communities on a continental scale.

Viruses are omnipresent, yet the knowledge on drivers of viral prevalence in wild host populations is often limited. Biotic factors, such as sympatric managed host species, as well as abiotic factors, such as climatic variables, are likely to impact viral prevalence. Managed and wild bees, which harbor several multi-host viruses with a mostly fecal-oral between-species transmission route, provide an excellent system with which to test for the impact of biotic and abiotic factors on viral prevalence in wild host populations.

Towards Integrated Pest and Pollinator Management in Intensive Pear Cultivation: A Case Study from Belgium.

Recently, the concept of Integrated Pest Management (IPM) was further extended into Integrated Pest and Pollinator Management (IPPM). Implementation of IPPM strategies entails the combination of actions for pest and pollinator management providing complementary or synergistic benefits for yield and/or quality of the harvest. The aim of this study was to examine IPPM elements (i.

Efficacy and biosafety assessment of neuropeptide CAPA analogues against the peach-potato aphid (Myzus persicae).

Insect CAPA neuropeptidesare considered to affect water and ion balance by mediating the physiological metabolism activities of the Malpighian tubules. In previous studies, the CAPA-PK analogue 1895 (2Abf-Suc-FGPRLamide) was reported to decrease aphid fitness when administered through microinjection or via topical application. However, a further statistically significant decrease in the fitness of aphids and an increased mortality could not be established with pairwise combinations of 1895 with other CAPA analogue.

More is less: mass-flowering fruit tree crops dilute parasite transmission between bees.

Parasites influence wild bee population dynamics and are regarded as one of the main drivers of wild bee decline. Most of these parasites are mainly transmitted between bee species via the use of shared floral resources. Disturbance of the plant-pollinator network at a location can hence disturb the transmission of these parasites.

Managed bumble bees acquire parasites from their foraging environment: A case study on parasite spillback.

The use of commercially reared bumble bees in agricultural environments has been recognized as a potential threat to wild pollinators due to competition, genetic contamination, and most notably, disease transmission. Higher parasite prevalence near greenhouses where managed bumble bees are used has been linked to parasite spillover from managed to wild bees. However, pathogen transmission is not unidirectional, and can also flow from wild to managed bees.

Network Centrality as an Indicator for Pollinator Parasite Transmission via Flowers.

Parasites are important actors within ecosystems. However, a key aspect to unraveling parasite epidemiology is understanding transmission. The bee pollinator community harbors several multihost parasites, which have been shown to be able to spread between species via flowers.

Bee Viruses: Routes of Infection in Hymenoptera.

Numerous studies have recently reported on the discovery of bee viruses in different arthropod species and their possible transmission routes, vastly increasing our understanding of these viruses and their distribution. Here, we review the current literature on the recent advances in understanding the transmission of viruses, both on the presence of bee viruses in and non- bee species and on the discovery of previously unknown bee viruses. The natural transmission of bee viruses will be discussed among different bee species and other insects.

Diversity and Global Distribution of Viruses of the Western Honey Bee, .

In the past centuries, viruses have benefited from globalization to spread across the globe, infecting new host species and populations. A growing number of viruses have been documented in the western honey bee, . Several of these contribute significantly to honey bee colony losses.

Double-stranded RNA reduces growth rates of the gut parasite Crithidia mellificae.

Parasites of managed bees can disrupt the colony success of the host, but also influence local bee-parasite dynamics, which is regarded as a threat for wild bees. Therapeutic measures have been suggested to improve the health of managed bees, for instance, exploiting the bees' RNA interference (RNAi) pathway to treat against viral pathogens. Gut trypanosomes are an important group of bee parasites in at least two common managed bee species, i.

Establishment of wildflower fields in poor quality landscapes enhances micro-parasite prevalence in wild bumble bees.

The current worldwide pollinator decline is caused by the interplay of different drivers. Several strategies have been undertaken to counteract or halt this decline, one of which is the implementation of wildflower fields. These supplementary flowers provide extra food resources and have proven their success in increasing pollinator biodiversity and abundance.

Infection with the multi-host micro-parasite Apicystis bombi (Apicomplexa: Neogregarinorida) decreases survival of the solitary bee Osmia bicornis.

The micro-parasites present in the Apidae pollinator community are mostly multi-host pathogens. To study the impact of these multi-host pathogens on the Apidae pollinator community, as a driver of wild bee decline, pathological studies are needed for different hosts. Yet data on the pathogenesis of these pathogens for different genera and species is scarce or lacking, especially for solitary bee species.

Interaction effects of different drivers of wild bee decline and their influence on host-pathogen dynamics.

Wild bee decline is a multi-factorial problem, yet it is crucial to understand the impact of a single driver. Hereto the interaction effects of wild bee decline with multiple natural and anthropogenic stressors need to be clear. This is also true for the driver 'pathogens', as stressor induced disturbances of natural host-pathogen dynamics can unbalance settled virulence equilibria.

Systemic Israeli acute paralysis virus (IAPV) infection in bumblebees (Bombus terrestris) through feeding and injection.

Israeli acute paralysis virus (IAPV) can cause a systemic infection, resulting in mortality in both Apis and Bombus spp. bees. However, little is known about the virus infection dynamics within bee tissues.

Absence of Leishmaniinae and Nosematidae in stingless bees.

Bee pollination is an indispensable component of global food production and plays a crucial role in sustainable agriculture. The worldwide decline of bee populations, including wild pollinators, poses a threat to this system. However, most studies to date are situated in temperate regions where Apini and Bombini are very abundant pollinators.

Large pathogen screening reveals first report of Megaselia scalaris (Diptera: Phoridae) parasitizing Apis mellifera intermissa (Hymenoptera: Apidae).

As it is most likely that global warming will also lead to a shift in pollinator-habitats northwards, the study of southern species becomes more and more important. Pathogen screenings in subspecies of Apis mellifera capable of withstanding higher temperatures, provide an insight into future pathogen host interactions. Screenings in different climate regions also provide a global perspective on the prevalence of certain pathogens.

The Effect of Oral Administration of dsRNA on Viral Replication and Mortality in Bombus terrestris.

Israeli acute paralysis virus (IAPV), a single-stranded RNA virus, has a worldwide distribution and affects honeybees as well as other important pollinators. IAPV infection in honeybees has been successfully repressed by exploiting the RNA interference (RNAi) pathway of the insect's innate immune response with virus-specific double stranded RNA (dsRNA). Here we investigated the effect of IAPV infection in the bumblebee Bombus terrestris and its tissue tropism.

The immune response of the small interfering RNA pathway in the defense against bee viruses.

Most bee viruses are RNA viruses belonging to two major families of Dicistroviridae and Iflaviridae. During viral infection, virus-derived double stranded RNAs activate a major host innate immune pathway, namely the small interfering RNAs pathway (siRNA pathway), which degrades the viral RNA or the viral genome. This results in 21-22 nucleotide-long virus-derived siRNAs (vsiRNAs).