Toxicity of abamectin to the terrestrial isopod Porcellio scaber (Isopoda, Crustacea)

Abstract

To determine effects of the antiparasitic veterinary drug abamectin on the isopod Porcellio scaber, animals were exposed for 21 days to Lufa 2.2 soil spiked at concentrations of 3-300 mg/kg dry soil. After exposure, abamectin residues in the isopods were analysed using a novel analytical method. Toxicity was evaluated on different levels of biological organisation: biochemical, cellular and the individual organism. Measurements included glutathione S-transferase (GST) activity and stability of cell membranes in the digestive gland, animal mass gain or loss, food consumption, behaviour and mortality. LC50 for the effect of abamectin on survival of P. scaber was 71 mg/kg dry soil. The most obvious sublethal effects were reduced food consumption and decreased body mass (NOEC 3 mg/kg dry soil). Additionally, loss of digging activity and reduced GST activity (NOEC 30 mg/kg dry soil) and cell membrane destabilization (NOEC 10 mg/kg dry soil) were recorded. Abamectin only slightly accumulated in the isopods, with bioaccumulation factors always being \0.1. Based on these results and current information on environmental levels of abamectin, it is not likely that isopods will be affected by abamectin, but further studies with exposure through faeces are recommended.

The toxicological impact of some avermectins on human erythrocytes glutathione S‐transferase enzyme

“…Contradictory results have been reported concerning the effect of avermectins on GST levels in the literature. It was reported that avermectins increased GST activity in some mites and whitefly and did not change it in the Brazilian populations of tomato leaves . Similar studies have also been investigated in some animal tissues for carbonic anhydrase (CA) enzyme activity .…”

“…Li et al reported that avermectins reduced SOD activity and increased POD and GST enzyme activity in vitro. Kolar et al expressed that abamectin did not induced GST activity in vivo, and GST had a minor role in the detoxification of abamectin. Contradictory results have been reported concerning the effect of avermectins on GST levels in the literature.…”

Soil ecotoxicology: state of the art and future directions

“…Several different endpoints have been proposed, but considering the difficulty of culturing Porcellio scaber in the laboratory survival, growth and food consumption rate so far have been used most frequently (see e.g. Odendaal and Reinecke 2004, Nolde et al 2006, Kolar et al 2010). Another interesting endpoint may be related to the composition of the gut microflora of isopods (Drobne et al 2002).…”

Bioaccumulation of hexachlorobenzene in the terrestrial isopod Porcellio scaber

“…Porcellio scaber has been used for metal toxicity testing of various elements such as zinc , cadmium , and cobalt , considering different lethal and sublethal endpoints. In addition, the toxic effects of nanoparticles like titanium dioxide and different organic compounds have been investigated with P. scaber . However, a standardized test protocol is still lacking.…”