Biology subjects

Lamas, Z. S.

Publications and source records attributed to Lamas, Z. S..

6 recordsLinked to original sources

bioRxiv2024

Nano Colonies: Rearing honey bee queens and their offspring in small laboratory arenas

Honey bees create complex societies of self-organized individuals in intricate colonies. Studies of honey bees are carried out in both the field and the laboratory. However, field research is encumbered by the difficulties of making reliable observations and environmental confounders. Meanwhile, laboratory trials produce data that are not field realistic as they lack key characteristics of a natural colony. Additionally, advances in honey bee research have been hindered without reliable methodology to rear queens in the laboratory. Here we provide a new system to reliably produce queens and worker brood in the laboratory and describe how this system fits with artificial insemination of queens as a step towards a continuous self-contained source of bees. The process creates a bridge between field research and laboratory trials and provides a secure system for contagious or regulated elements while maintaining many of the intrinsic characteristics of a honey bee colony.

zoology↗

bioRxiv2022

Oversharing by honey bees and the spread of viruses

Deformed wing virus (DWV) is an emerging insect pathogen efficiently transmitted through communicable and vector-borne routes with Apis mellifera. Continual transmission of DWV between hosts and vectors is required for maintenance of the pathogen within the population, and this vector-host-pathogen system offers unique disease transmission dynamics for pathogen maintenance between vector and a social host. In a series of experiments, we study how vector-vector, host-host and host-vector transmission routes maintain DWV in a honey bee population. We found co-infestations on shared hosts allowed for movement of DWV from mite to mite. Additionally, two social behaviors of the honeybee, trophallaxis and cannibalization of pupae, provide routes for communicable transmission from bee to bee. Communicable circulation of the virus solely amongst hosts was then shown to act as a reservoir of DWV for naive Varroa to acquire and subsequently vector the pathogen. Our findings illustrate communicable transmission between hosts can maintain and influence the future acquisition and vectoring of a pathogen by a vector. There are a handful of other infectious diseases, both zoonotic and which impact human health, that have potentially similar transmission dynamics.

pathology↗

bioRxiv2022

The vectoring competence of the mite Varroa destructor for Deformed wing virus of honey bees is highly dynamic and affects survival of the mite.

The ectoparasitic mite, Varroa destructor and the viruses it vectors, including types A and B of Deformed wing virus (DWV), pose a major threat to honey bees, Apis mellifera. Analysis of 256 mites collected from the same set of colonies on five occasions from May to October 2021 showed that less than a half of them, 39.8% (95% confidence interval (CI): 34.0 - 46.0%), were able to induce an overt-level DWV infection with more than 109 viral genomes per bee in the pupa after 6 days of feeding, with both DWV-A and DWV-B being vectored at similar rates. To investigate the effect of the phoretic stage on the mites ability to vector DWV, the mites from two field collection events were divided into two groups, one of which was tested immediately for their infectiveness, and the other was kept with adult worker bees in cages for 12 days prior to testing their infectiveness. We found that while 39.2 % (95% CI: 30.0 - 49.1%) of the immediately tested mites induced overt-level DWV infections, 12-day phoretic passage significantly increased the infectiousness of mites to 89.8% (95% CI: 79.2 - 95.6%). It is likely that Varroa mites that survive brood interruptions in field colonies are increasingly infectious. We found that mite lifespan was significantly affected by the type of DWV it transmitted to pupae. The mites, which induced overt DWV-B but not DWV-A infection had an average lifespan of 15.5 days (95% CI: 11.8 - 19.2 days), which was significantly shorter than those of the mites which induced overt DWV-A but not DWV-B infection, with an average lifespan of 24.3 days (95% CI: 20.2 - 28.5), or the mites which did not induce high levels of DWV-A or DWV-B, with an average survival of 21.2 days (95% CI: 19.0 - 23.5 days). The mites which transmitted high levels of both DWV-A and DWV-B had an intermediate average survival of 20.5 days (95% CI: 15.1 - 25.9 days). The negative impact of DWV-B on mite survival could be a consequence of the ability of DWV-B, but not DWV-A to replicate in Varroa mites.

microbiology↗

bioRxiv2022

Promiscuous feeding across multiple honey bee hosts amplifies the vectorial capacity of Varroa destructor

Varroa destructor is a cosmopolitan pest and leading cause of colony loss of the European honey bee. Historically described as a competent vector of honey bee viruses, this arthropod vector is cause for the global pandemic of Deformed wing virus, now endemic in honeybee populations. Our work shows viral spread is driven by Varroa actively switching from one adult bee to another as they feed. Assays using fluorescent microspheres were used to show the movement of fluids in both directions between host and vector when Varroa feed. Therefore, Varroa could be in either an infectious or naive state dependent upon the disease status of their host. We tested this and confirm that the relative risk of a Varroa feeding was dependent on the infectiousness of their previous host. Varroa exhibit remarkable heterogeneity in their host switching behavior, with some Varroa switching infrequently while others switch at least daily. As a result, relatively few of the most active Varroa parasitize the majority of bees. This multiple feeding behavior has analogs in vectorial capacity models of other systems, where promiscuous feeding by individual vectors is a leading driver of vectorial capacity. We propose that the honeybee-Varroa relationship offers a unique opportunity to apply principles of vectorial capacity to a social organism, as virus transmission is both vectored and occurs through multiple host-to-host routes common to a crowded society.

animal behavior and cognition↗

bioRxiv2020

Pupal cannibalism by worker honey bees contributes to the spread of Deformed wing virus.

Transmission routes impact pathogen virulence and genetics, therefore comprehensive knowledge of these routes and their contribution to pathogen circulation is essential for understanding host-pathogen interactions and designing control strategies. Deformed wing virus (DWV), a principal viral pathogen of honey bees associated with increased honey bee mortality and colony losses, became highly virulent with the spread of its vector, the ectoparasitic mite Varroa destructor. Reproduction of Varroa mites occurs in capped brood cells and mite-infested pupae from these cells usually have high levels of DWV. The removal of mite-infested pupae by worker bees, Varroa Sensitive Hygiene (VSH), leads to cannibalization of pupae with high DWV loads, thereby offering an alternative route for virus transmission. We used genetically tagged DWV to investigate virus transmission to and between worker bees following pupal cannibalisation under experimental conditions. We demonstrated that cannibalization of DWV-infected pupae resulted in high levels of this virus in worker bees and that the acquired virus was then transmitted between bees via trophallaxis, allowing circulation of Varroa-vectored DWV variants without the mites. Despite the known benefits of hygienic behaviour, it is possible that higher levels of VSH activity may result in increased transmission of DWV via cannibalism and trophallaxis.

microbiology↗

bioRxiv2020

Social Disruption: Sublethal pesticides in pollen lead to Apis mellifera queen events and brood loss

Eusocial Apis mellifera colonies depend on queen longevity and brood viability to survive, as the queen is the sole reproductive individual and the maturing brood replenishes the shorter lived worker bees. Production of many crops rely on both pesticides and bee pollination to improve crop quantity and quality. We looked at the resiliency of queens and their brood after one month of sublethal exposure to field relevant doses of pesticides that mimic exposure during commercial pollination contracts. We exposed full size colonies to pollen contaminated with field-relevant doses of the fungicides (chlorothalonil and propicanizole), insecticides (chlorypyrifos and fenpropathrin) or both, noting a significant reduction in pollen consumption in colonies exposed to fungicides compared to control. While we found no difference in the total amount of pollen collected per colony, a higher proportion of pollen to non-pollen foragers was detected in all pesticide exposed colonies. After ceasing treatments we measured brood development, discovering a significant increase in brood loss and/or cannibalism across all pesticide exposed groups. Sublethal pesticide exposure in general was linked to reduced production of replacement workers and a change in protein acquisition (pollen vs. non-pollen foraging). Fungicide exposure also resulted in increased loss of the reproductive queen.

animal behavior and cognition↗