Effects of perchlorate bioaccumulation on Spodoptera litura growth and sex ratio

Qin, Junhao; Shu, Yinghua; Li, Yongjun; He, Hongzhi; Li, Huashou

Effects of perchlorate bioaccumulation on Spodoptera litura growth and sex ratio

2016

Qin, Junhao | Shu, Yinghua | Li, Yongjun | He, Hongzhi | Li, Huashou

Perchlorate (ClO₄ ⁻) pollution is widespread in the natural environment, but the effects of ClO₄ ⁻ on the terrestrial insects are rarely studied. Here, when phytophagous insect Spodoptera litura larvae were fed on the diets with different ClO₄ ⁻ concentrations, changes in their life-history traits were recorded; ClO₄ ⁻ accumulations in feces and insect body were detected. The results demonstrated that ClO₄ ⁻ bioaccumulation in insect at the different developmental stages was ranked in the order: adults > pupae > the 4th > 5th > 6th instar larvae. Besides, ClO₄ ⁻ accumulations in the feces were ranked in the order: the 6th > 5th > 4th instar larvae. The ClO₄ ⁻ accumulations in female pupae and adults were significantly higher than that in males. ClO₄ ⁻ bioaccumulation in insect prolonged larval development time and caused a skewed sex ratio (the percentage of males at metamorphosis significantly decreased) under 100 to 200 mg ClO₄ ⁻/kg treatment. Therefore, ClO₄ ⁻ accumulations in S. litura body presented developmental stage-, sex-specific pattern, and the sex-specific ClO₄ ⁻ accumulations resulted in difference of sex ratio. These effects were observed at concentrations reported in natural environments contaminated with ClO₄ ⁻, suggesting that this contaminant may pose a threat to the normal development and growth of this insect species.

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