Performing Department
(N/A)
Non Technical Summary
Non-Technical SummaryThere are currently no integrated pest management (IPM) strategies for A. apis infections, or chalkbrood, which are rooted in scientific evidence. Extension agents and apiary inspectors do not have science-based strategies to recommend when beekeepers encounter chalkbrood in their operations. This makes it difficult for beekeepers to effectively address disease outbreaks within their own apiaries, thus leading to frustration, economic loss, and colony death. The results from our proposed work will allow us to communicate chalkbrood IPM strategies which are quantifiably effective in preventing and treating chalkbrood. By forming a variety of IPM strategies, we are following best management practices for sustainable and responsible disease management within our crop system and ultimately generating a holistic toolkit for our beekeeping stakeholders.A. apis, although a global honey bee parasite, is currently understudied in the U.S. which gives us ample knowledge gaps to fill. Understanding what makes some groups in a single honey bee population more resistant than others is scientifically valuable and has wide applicability to other diseases and pests within social insects. A. apis surprisingly seems to have few consistent responses globally, which may indicate differential virulence of different strains or variance in responses of different honey bees populations. Our work would both fill several knowledge gaps as well as generate promising areas of future study, such as seeing if different strains of A. apis are equally susceptible to our treatment methods, and identifying molecular mechanisms associated with social immunity behaviors in response to A. apis infection.Additionally, by incorporating future and current career scientists into this project, we are helping to both generate scientific and stakeholder-centered information, as well as training future peers to communicate their findings widely which is important to STEM and to society. We ultimately propose a thorough dissemination of the knowledge through both scientifically peer-reviewed and stakeholder-centered avenues, putting this information into the hands of the beekeepers who need it most.
Animal Health Component
100%
Research Effort Categories
Basic
11%
Applied
78%
Developmental
11%
Goals / Objectives
Goals and Objectives of "No More Mummies: Novel and integrative treatment options for Ascosphaera apisin honey bees"GoalsOur primary goal is to improve the health and productivity of honey bee colonies by reducing colony losses to chalkbrood disease caused by the fungal pathogen Ascosphaera apis. To do this, we will establish a treatment regiment which encompasses both non-chemical and chemical approaches to ultimately reduce chalkbrood infection in honey bee colonies, training future colleagues and communicating our findings with beekeeping stakeholders throughout the process.Objective 1: Identify promising synthetic and natural chemical compounds that reduce or prevent the growth of Ascosphaera apis and determine their impact to honey bees in laboratory trials. No current treatments are available for beekeepers to combat chalkbrood infections in colonies. We have identified some compounds and will explore others through a series of laboratory-based experiments focusing on cultured A. apis (Obj. 1a), in vitro reared bee larvae (Obj. 1b), and adult honey bees (Obj. 1c).Objective 2: Characterize social and individual immune traits that contribute to chalkbrood resistance. Several honey bee stocks have demonstrated abilities to reduce pests and pathogens naturally, although the mechanisms for this are yet unknown. Previous studies have demonstrated that Russian honey bees in particular have varying susceptibility to chalkbrood. Through both field (Obj. 2a) and laboratory (Obj. 2b) experiments, we will quantify the contribution of key colony-level social immune and individual immune mechanisms of resistance among various lines of Russian honey bees.Objective 3: Investigating and communicating the efficacy of integrative pest management practices for chalkbrood disease. Propolis has is a potent pathogen inhibitor, both in the laboratory and in field settings. Here, we will test the impact of propolis-rich boxes (Obj. 3a) and the newly identified fungicidal compounds (Obj. 3b) to infected colonies in the field separately. Then we will test them in concert with colonies of differing susceptibility to evaluate potential additive benefits of multiple control strategies (Obj. 3c). Finally, we will synthesize our findings into best practices for IPM of chalkbrood disease and broadly disseminate this message to beekeepers worldwide (Obj. 3d).Understanding what makes some groups in a single honey bee population more resistant than others is scientifically valuable and has wide applicability to other diseases and pests within social insects. The results from our proposed work will allow us to communicate chalkbrood IPM strategies which are quantifiably effective in preventing and treating chalkbrood and likely other honey bee diseases through shared social immunity mechanisms. By forming a variety of IPM strategies, we are following best management practices for sustainable and responsible disease management within our crop system and ultimately generating a holistic toolkit for our beekeeping stakeholders.Objectives ListObjective 1: Identify promising synthetic and natural chemical compounds that reduce or prevent the growth of Ascosphaera apis in the laboratory and within individual honey beeso Objective 1a: Screen synthetic and natural chemical compounds for reduction and prevention of A. apis growth on mediao Objective 1b: Determine the effectiveness of compounds in controlling chalkbrood infection of in vitro reared larvaeo Objective 1c: Assess the ability of antifungal compounds to impact the main route of spore transmission from nurse bees to larvaeObjective 2: Determine if any U.S. honey bee stocks are able to naturally reduce instances of chalkbrood infection without beekeeper interventiono Objective 2a: Identify Russian honey bee (RHB) lines that are particularly resistant or susceptible to chalkbrood in the field.o Objective 2b: Determine if resistant or susceptible colony status is due to differential vulnerability of larvae in the laboratory.Objective 3: Developing an integrative pest management program for chalkbroodo Objective 3a: Evaluate if propolis boxes prevent chalkbrood infections in a field setting.o Objective 3b: Assess if promising fungicides can treat chalkbrood infections in a field setting.o Objective 3c: Determine if there is an additive effect of increased propolis and fungicidal treatment on chalkbrood infections for colonies of varying susceptibilityo Objective 3d: Construct technology transfer materials of chalkbrood IPM to stakeholders.
Project Methods
MethodsEffortsObjective 1Different synthetic fungicides and propolis extracts will be evaluated on media according to standard methodology to determine which inhibit Ascosphaera apis growth. Promising fungicidal compounds will then be evaluated after use on honey bee larvae reared in the laboratory (determine LD50) and then further to determine if larvae infected with A. apis and then treated with compounds have a higher chance of survival. Finally, caged newly emerged bees (typically nurses at this age) who routinely vector chalkbrood throughout the colony during outbreaks will be inoculated with A. apis inside of cages in incubators and then treated with the promising fungicidal compounds in order to both determine adult LD50s and potential utility killing A. apis spores while inside of the honey bee proboscis and gut.Objective 2Using historical data in conjunction with recent identifications, we will assess different breeding groups of Russian honey bees (RHB) which have already demonstrated resistance to chalkbrood (the disease caused by A. apis) in previous work completed at the location where we will complete the work. We will measure social immunity traits routinely associated with resistance to other diseases. Resistant and susceptible colonies in the field will used for laboratory assessments of resistance and susceptibility conducted on grafted larvae reared in the laboratory.Objective 3In the field, we will inoculate colonies with A. apis and then utilize all promising treatment options including propolis boxes, promising fungicides, etc. and then conduct final assessments of efficacy. Findings will be communicated to stakeholders and those who primarily work with stakeholders.EvaluationObjective 1We expect to find several additional fungicides in different chemical classes that are able to significantly restrict the growth of chalkbrood. We will significantly increase our screening efforts for chemicals from each class of fungicides and propolis from different geographic origins and plant sources. The results will be written for publication in an international peer-reviewed journal (Objective 1a). We want to continue evaluating the compounds that have the lowest honey bee mortality and the greatest survival when co-exposed along with A. apis spores, but we need to identify those before we can continue evaluations (Objective 1b). We will discover if our fungicides show promising potential to control A. apis inboth honey bee larvae and adult workers (Objectives 1b and 1c), deepening our knowledge of this process and further informing Objective 3b.Objective 2We anticipate a variable response in hygienic behavior and mummy production between different Russian honey bee (RHB) breeding lines (Objective 2a). We suspect that hygienic behavior will negatively correlate with mummy production, as it did historically in the U.S. This result would indicate that RHB and/or the Southeastern U.S. strain of A. apis are very different than the those in Australia, as hygienic behavior is not correlated in any way with mummy production in Australia (where we currently have the most recent data about chalkbrood-honey bee disease ecology).We expect to find that breeding groups that are highly susceptible or highly resistant to A. apis correlate with having larvae which are highly susceptible or highly resistant to A. apis (Objective 2b), this would support the evidence found previously which identified inherited single nucleotide polymorphisms with susceptibility and further explain the variation in findings between RHB susceptibility and resistance to chalkbrood.Objective 3We fully expect that non-chemical based IPM strategies work well to prevent chalkbrood and that the synthetic and non-synthetic treatment options will work in the field as they have already shone great promise in laboratory settings. The Premier Bee Products propolis boxes are a simple and low-energy way for beekeepers to utilize propolis in a field relevant setting, but they are a new product and have not been tested until now. Propolis has worked well to inhibit A. apis growth in the laboratory and field previously, so we do expect the propolis boxes to work well as a preventative management strategy for chalkbrood (Objective 3a). The propolis spray and fungicides (Objective 1) have both inhibited A. apis growth to varying degrees in laboratory settings, so we do expect these results to also inhibit A. apis growth in a field setting (Objective 3b). In total, the toolkit of individual IPM strategies that we are investigating should have an additive negative effect on chalkbrood infections--or mummy production--in colonies (Objective 3c). The information which results from these objectives needs to be synthesized into a coherent IPM strategy toolkit which can be disseminated to the beekeeping industry (Objective 3d), where we expect it will be well-received.