Effects of Long-Term Exposure to Cadmium on Development, Reproduction and Antioxidant Enzymes of Aleuroglyphus ovatus (Acari: Acaridae)

SIMPLE SUMMARY: Cadmium is one of the major metal pollutants in grain, threatening food safety and human health. There is an urgent need to find an organism that is prevalent in grain and which can be used as a biological model for determining and assessing the effects of long-term heavy metal contamination in offspring. The findings in this study showed that long-term cadmium exposure could adversely affect the development, reproduction and physiology of Aleuroglyphus ovatus (Acari: Acaridae). A. ovatus was sensitive to cadmium, which could be a valuable tool for studying the toxicity of long-term heavy metal exposure on offspring. Simultaneously, there is little report about this study, providing a basis for future evaluation of cadmium pressure on genetic evolution. ABSTRACT: Grain contaminated by cadmium (Cd) has become a serious food security problem, and it is necessary to determine and evaluate the toxic effect and defense mechanism of long-term heavy metal pollution in grain. In order to evaluate the effects of long-term heavy metal Cd stress on the stored grain pests, Aleuroglyphus ovatus were fed with an artificial diet supplemented with different concentrations of Cd (0, 5, 10, 20 mg/kg). The development, fecundity and detoxification enzymes of A. ovatus were analyzed and observed. In this study, the immature duration of A. ovatus was significantly prolonged under long-term Cd stress. Moreover, the survival duration of female adults was significantly shortened. The total number of eggs laid and the daily number laid per female adult decreased significantly. There were significant differences in protein content at protonymph and tritonymph stages when the concentration of Cd exceeded 10 mg/kg. The protein content of female adults was higher than that of male adults. The activity of detoxification enzymes showed differences in different conditions, such as development stage, Cd concentration and gender. These findings confirmed that A. ovatus were sensitive to Cd, and their offspring were severely affected under long-term Cd stress. Therefore, A. ovatus is a good model for evaluating the toxicity of long-term heavy metal Cd stress. The study provides the basis and enriches the research content of heavy metal pollution on mites, contributing to the harmonious and healthy development between the environment and human beings.