Beetles Research Paper
In this study, the comparative effects of IVM and MOX on adult dung beetles were assessed for the first time examining both physiological sub-lethal symptoms and pre-lethal consequences after somatic paralysis.
Following the same methodological guidelines proposed previously, both the sensorial response of antennae (sub-lethal effect) and irreversible ataxia of somatic muscles (pre-lethal effect) were examined by exposing a model dung beetle species (Scarabaeus cicatricosus (Lucas, 1846); Coleoptera, Scarabaeidae) to both IVM and MOX under different dose concentrations.
normalised response models allowed for the interpolation of concentrations of both VMPs that inhibited the antennal response in S.
cicatricosus adults by 50% (IC) (95% CV intervals), calculated from dose-response curves presented in Fig.
Other studies reported that dung beetle species, such as Digitonthophagus gazella (F.
GABA-gated chloride ion channels are present in neurons and abundant in local interneurons and antennal lobes of insects receptors have been observed in olfactory sensory neurons in the male antenna of Heliothis virescens (F., 1777), initiating a GABA-mediated gain control mechanism that could play a pivotal role in processing pheromone signals Comparison of the chemical structure of ivermectin (IVM) and moxidectin (MOX).
Inhibition of antennal response and ataxia were tested as two intuitive and ecologically relevant parameters by obtaining the lowest observed effect concentration (LOEC) values and interpolating other relevant toxicity thresholds derived from concentration-response curves (IC, as the quantity of ingested ML where partial paralysis was observed by half of treated individuals) from concentration-response curves.
Both sub-lethal and pre-lethal symptoms obtained in this study coincided in that IVM was six times more toxic than MOX for adult dung beetles.
The substituents that differ from IVM and MOX are highlighted in orange and blue, respectively. Among the non-target organisms affected by these substances, dung beetles are particularly sensitive.
Dung beetles are considered one of the most important groups within dung pat assemblages in terms of number of species, abundance, biomass and ecosystem services.