Lévy flights are scale-free (fractal) search patterns found in a wide range of animals. They can be an advantageous strategy promoting high encounter rates with rare cues that may indicate prey items, mating partners or navigational landmarks. The robustness of this behavioural strategy to ubiquitous threats to animal performance, such as pathogens, remains poorly understood. Using honeybees ra...

Honey bees (Apis mellifera) host a wide range of parasites, some being known contributors towards dramatic colony losses as reported over recent years. To counter parasitic threats, honey bees possess effective immune systems. Because immune responses are predicted to cause substantial physiological costs for infected individuals, they are expected to trade off with other life history traits th...

There is increasing appreciation that hosts in natural populations are subject to infection by multiple parasite species. Yet the epidemiological and ecological processes determining the outcome of mixed infections are poorly understood. Here, we use two intracellular gut parasites (Microsporidia), one exotic and one co-evolved in the western honeybee (Apis mellifera), in an experiment in which...

Microsporidia are ubiquitous intracellular pathogens whose opportunistic nature led to their increased recognition with the rise of the AIDS pandemic. As the RNA world was largely unexplored in this parasitic lineage, we developed a dedicated in silico methodology to carry out exhaustive identification of ncRNAs across the Encephalitozoon and Nosema genera. Thus, the previously missing U1 small...

Transmission plays an integral part in the intimate relationship between a host insect and its pathogen that can be altered by abiotic or biotic factors. The latter include other pathogens, parasitoids, or predators. Ants are important species in food webs that act on various levels in a community structure. Their social behavior allows them to prey on and transport larger prey, or they can dis...

Nosema bombycis (N. bombycis, Nb) is a fungus-related and obligate intracellular parasite that causes chronic pebrine disease in the silkworm. After infecting the host, spores obtain energy from host cells and survive for several days. This symbiosis between the pathogen and the host cell suggests that N. bombycis prevents apoptosis and reactive oxygen species (ROS) production of host cells to ...

Sudden and severe declines in honey bee (Apis mellifera) colony health in the US and Europe have been attributed, in part, to emergent microbial pathogens, however, the mechanisms behind the impact are unclear. Using roundabout flight mills, we measured the flight distance and duration of actively foraging, healthy-looking honey bees sampled from standard colonies, before quantifying the level ...

In ecosystems, a variety of biological, chemical and physical stressors may act in combination to induce illness in populations of living organisms. While recent surveys reported that parasite-insecticide interactions can synergistically and negatively affect honeybee survival, the importance of sequence in exposure to stressors has hardly received any attention. In this work, Western honeybees...

Numerous methods exist for molecular-based detection of Nosema ceranae. Here we determine location of parasite loads, the optimal tissue for pathogen detection, and the likely sources of variability among assays. Bee washes and head/thorax samples revealed substantial N. ceranae loads (2.67×10(4)±1.12×10(4) and 1.83×10(4)±4.14×10(3)). Midgut samples carried the highest parasite loads (3.42×10(6...

Western honey bees (Apis mellifera) face an increasing number of challenges that in recent years have led to significant economic effects on apiculture, with attendant consequences for agriculture. Nosemosis is a fungal infection of honey bees caused by either Nosema apis or N. ceranae. The putative greater virulence of N. ceranae has spurred interest in understanding how it differs from N. api...