Effects of Avermectins on the Environment Based on Its Toxicity to Plants and Soil Invertebrates—a Review

Abstract

Avermectins are pharmaceutical drugs widely used mainly in livestock to combat both ectoparasites and endoparasites. Drugs belonging to this family include ivermectin, abamectin, doramectin, selamectin, eprinomectin, and emamectin benzoate, and they share similar chemical characteristics. When administered to livestock, between 80 and 98% of the drug is estimated to leave the body without being metabolized in feces, thus reaching the soil. For this reason, concern for avermectin contamination in soil is increasing, and researchers are focused on estimating the effects on non-target organisms, such as plants and soil invertebrates. This review aimed to compile and discuss updated data of avermectin toxicity on non-target organisms to better comprehend its effect on the environment. Effects on plants are scarcely studied, since they were not believed to absorb these drugs. However, recent studies suggest that plants can be negatively affected. Regarding soil invertebrates, negative effects such as increased mortality and reduced reproduction are best known to dung-beetles. Recently, some studies have also suggested that earthworms, springtails, and enchytraeids can be adversely affected by avermectin exposure. Since ivermectin was the first avermectin marketed, most of the data refers to this product. According to new data on scientific literature, avermectins can now be considered harmful to non-target organisms, and its prudent use is recommended in order to reduce negative effects on the environment. For future investigations, inclusion of avermectins other than ivermectin, as well as field and “omics” studies is suggested.

Biotic interactions in soil and dung shape parasite transmission in temperate ruminant systems: An integrative framework

“…Sequestration of parasite stages within dung for later appearance on pasture might itself be beneficial to their control, for example, buying time for parasite evasion by livestock through rotational grazing or acting as a source of refugia for drug‐susceptible genotypes (Hodgkinson et al, 2019). Studies on effects at the farm and landscape levels are needed to properly assess the potential for dung beetle augmentation as a nature‐based or biocontrol intervention, as well as the consequences of nontarget effects of anthelmintics on them (de Souza & Guimarães, 2022; Jacobs & Scholtz, 2015; Manning et al, 2018). Furthermore, farm‐level studies that explore the abundance, succession, and longevity of dung beetle augmentation may also be important, to consider the feasbility of increasing dung beetle populations.…”

Strongyloides in non-human primates: significance for public health control

“…Regular dehelminthization is an advisable approach to control helminths in domestic dog populations [99]; however, there are no anthelmintic products formally licensed for treatment and prophylaxis of canine Strongyloides infections [100]. In the case of wildlife, such as NHP, administration of any anthelmintics has ethical constraints, including potential adverse impacts on the animals as well as on the environment [101], and the decision to medicate should not be made on the basis of individuals' own will or initiatives. Although human strongyloidiasis has recently been added to the list of neglected tropical diseases requiring control measures in endemic areas [102], effective treatment strategies are far from being optimized.…”

Developing an Effective Push–Pull System for Managing Outbreaks of the Invasive Pest Bactrocera dorsalis (Diptera: Tephritidae) in Nephelium lappaceum Orchards

“…The first push-pull strategy compared the effectiveness of a push (allicin)-pull (ME) system with and without the use of low-concentration abamectin in controlling the outbreak of B. dorsalis. Abamectin is considered environmentally friendly, displaying minimal residue levels in water and easy biodegradability by soil microorganisms [36]. It is also known to have low toxicity towards avian species and humans [37,38].…”