Long‐term effects of antibiotic treatments on honeybee colony fitness: A modelling approach

Abstract

1. Gut microbiome disequilibrium is increasingly implicated in host fitness reductions, including for the economically important and disease-challenged western honey bee Apis mellifera. In laboratory experiments, the antibiotic tetracycline, which is used to prevent American Foulbrood Disease in countries including the US, elevates honey bee mortality by disturbing the microbiome. It is unclear, however, how elevated individual mortality affects colony-level fitness. 2. We used an agent-based model (BEEHAVE) and empirical data to assess colonylevel effects of antibiotic-induced worker bee mortality, by measuring colony size. We investigated the relationship between the duration that the antibiotic-induced mortality probability is imposed for and colony size. 3. We found that when simulating antibiotic-induced mortality of worker bees from just 60 days per year, up to a permanent effect, the colony is reduced such that tetracycline treatment would not meet the European Food Safety Authority's (EFSA) honey bee protection goals. When antibiotic mortality was imposed for the hypothetical minimal exposure time, which assumes that antibiotics only impact the bee's fitness during the recommended treatment period of 15 days in both spring and autumn, the colony fitness reduction was only marginally under the EFSA's threshold. 4. Synthesis and Applications. Modelling colony-level impacts of antibiotic treatment shows that individual honey bee worker mortality can lead to colony mortality. To assess the full impact, the persistence of antibiotic-induced mortality in honey bees must be determined experimentally, in vivo. We caution that as the domestication of new insect species increases, maintaining healthy gut microbiomes is of paramount importance to insect health and commercial productivity. The recommendation from this work is to limit prophylactic use of antibiotics and to not exceed recommended treatment strategies for domesticated insects. This is especially important for highly social insects as excess antibiotic use will likely decrease colony growth and an increase in colony mortality.

Varroa destructor from the Laboratory to the Field: Control, Biocontrol and IPM Perspectives—A Review

“…They indicated as well that prior to the generation of overwintering honeybees, the ecto-parasite pressure should be reduced [267][268][269]. An interesting point with the latest development in modelling approach remains in the study of sub-lethal doses of pesticides and their combined effect on the colonies [270] as well as the long-term effect of antibiotics on bees [271]. Even acute contact toxicity was predicted recently [272], advocating for a deeper connection between in silico, in vitro, semi-field and field experiments.…”

Characterization and Protective Properties of Lactic Acid Bacteria Intended to Be Used in Probiotic Preparation for Honeybees (Apis mellifera L.)—An In Vitro Study

“…An example is tylosin used to treat Paenibacillus larvae , the causative agent of American foulbrood [ 4 ]. However, the use of antibiotics can have a negative impact on honeybee health and induce the mortality of these pollinators [ 5 ]. Dysbiosis caused by exposure to antibiotics can be reduced by administering probiotics [ 6 ].…”

Simulation of Varroa mite control in honey bee colonies without synthetic acaricides: Demonstration of Good Beekeeping Practice for Germany in the BEEHAVE model

“…It includes a detailed foraging module, the option to load a realistic landscape and a varroa and virus model that enables various beekeeping practices. BEEHAVE was positively evaluated by the European Food Safety Agency (EFSA PPR Panel, 2015) and has been used to answer a variety of questions: Consequences of pesticide impacts at the colony level, both in hypothetical (Reiner et al, 2022; Rumkee et al, 2015; Thorbek et al, 2017a,b) and real‐world scenarios (Schmolke et al, 2019, 2020); and numerous others (Abi‐Akar et al, 2020; Agatz et al, 2019; Bulson et al, 2021; EFSA, 2021; Henry et al, 2017; Horn et al, 2016, 2021; Requier et al, 2019). Although the original BEEHAVE version (Becher et al, 2014) includes varroa treatment and a later version (BEEHAVE for BeeMapp, 2016) includes repeated treatments, drone brood removal, and mite reinvasion (referred to as reinfestation in BEEHAVE), not all varroa treatment options can be simulated.…”