Sub-chronic exposure to a neonicotinoid does not affect susceptibility of larval leopard frogs to infection by trematode parasites, via either depressed cercarial performance or host immunity

Toxicity of the neonicotinoid insecticides thiamethoxam and imidacloprid on tadpoles of four species of South American amphibians and effects of thiamethoxam on the metamorphosis of Rhinella arenarum

“…With respect to anuran metamorphosis, delays in completion have been reported for Xenopus laevis exposed to 20 and 100 mg/L of TIA and clothianidin (Jenkins et al, 2021), Lithobates pipiens tadpoles exposed to 8.5 mg/L and 250 ng/L of IMI (Moe et al, 2007), and Lithobates sylvaticus tadpoles exposed to 1 µg/L, 10 µg/L and 100 µg/L of IMI, although, in this case, the same concentrations of TIA had no effect on development time (Robinson et al, 2017). A lack of effect on development time was also reported for tadpoles of Acris blanchardi, Lithobates clamitans and Hyla chrysosceli exposed to 1 mg/L of IMI (Boone, 2018), Rana pipiens exposed to 2.5 and 250 ug/L of clothianidin and TIA (Robinson et al, 2019), and to 0,23, 1, 10 and 100 µg/L of clothianidin (Robinson et al, 2021). Finally, larvae of the Northwestern salamander (Ambystoma gracile) presented, in contrast, accelerated development, when exposed to 100 μg/L of IMI (Danis and Marlatt, 2021).…”

“…Sublethal exposures of frogs and sh to TIA and IMI have been shown to affect red and white blood cell counts (Gavel et al, 2019;Paunescu et al, 2022), endocrine systems (Lifei et al, 2019;Gavel et al 2019;Crayton et al, 2020), glycogenesis and blood glucose levels (Stoyanova et al, 2015;Vieira et al, 2018;Paunescu et al, 2022), oxidative stress and antioxidant response (Yan et al, 2015;Vieira et al, 2018), the escape response to predators (Lee-Jenkins y Robinson, 2018;Sweeney et al, 2020), as well as DNA damage and genotoxicity (Feng et al, 2004;Perez-Iglesias et al, 2014Yan et al, 2015;Iturburu et al, 2017;Moe, 2017;Vieira et al, 2018). For its part, clothianidin was found to induce oxidative stress and alter the leukocyte pro le in tadpoles of the frog Rana pipiens (Gavel et al, 2019;Robinson et al 2021); although it did not affect the susceptibility of larval leopard frogs to infection by trematode parasites (Robinson et al, 2019).…”

Host exposure to a common pollutant can influence diversity–disease relationships

“…For example, environmental perturbations in the host environment, including pollutant exposure (Linzey et al, 2003;Merrick & Searle, 2019;Milotic et al, 2017Milotic et al, , 2019, habitat alterations (e.g. urbanization; Bradley & Altizer, 2007) and the quality and/or quantity of resources available to hosts (Civitello et al, 2015) can all alter patterns of host competence by inducing shifts in host susceptibility (a component of host competence) to parasites (Milotic et al, 2017(Milotic et al, , 2019Robinson et al, 2019;Rohr et al, 2008).…”

“…For example, environmental perturbations in the host environment, including pollutant exposure (Linzey et al, 2003; Merrick & Searle, 2019; Milotic et al, 2017, 2019), habitat alterations (e.g. urbanization; Bradley & Altizer, 2007) and the quality and/or quantity of resources available to hosts (Civitello et al, 2015) can all alter patterns of host competence by inducing shifts in host susceptibility (a component of host competence) to parasites (Milotic et al, 2017, 2019; Robinson et al, 2019; Rohr et al, 2008). Environmental perturbations can influence these dynamics through impacts on host immunocompetence, reducing resistance to infection in some systems (Milotic et al, 2017; Rohr et al, 2008), or, conversely, increasing resistance to parasitic infections in others (Saha et al, 2022) or have no effect on infection dynamics.…”

“…Anthropogenic pollutants such as pesticides (Coors et al, 2008), per‐and polyfluoroalkyl substances (Brown et al, 2021), roadway deicing salts (Milotic et al, 2017) and antibiotics (Melchiorre et al, 2020) can alter host competence by modifying host susceptibility to parasites. Importantly, pollutant exposure can differentially influence host susceptibility between species, increasing or decreasing for some hosts and having no effect for others (Milotic et al, 2017; Robinson et al, 2019; Saha et al, 2022). As such, it is possible that pollutant exposure could influence the direction and magnitude of diversity–disease dynamics (i.e.…”