Distribution and bio-accumulation effect of trace element concentration in Nilaparvata lugens (Stål) (Homoptera, Delphacidae)

To study distribution and bio-acccumulation effect concentrations of trace elements in adults of the brown planthopper Nilaparvata lugens Stål (Homoptera, Delphacidae), the test insects, were artificially reared with de-ionized water on 24 h, 48 h, and 96 h, respectively, and the concentrations of 12 trace elements in N. lugens detected using inductively coupled-plasma mass spectrometry. It was proposed that a method to model the spatial-temporal changes of trace element concentrations in N. lugens. With this modeling, the trace elements were divided into three groups based on their spatial-temporal changes in concentrations of trace elements in N. lugens. The concentrations of trace elements in the three groups displayed bio-accumulation, dynamic balance, and bio-elimination respectively. In the first group, the concentrations of Zn and Cd were significantly higher in the organic tissue than in the alimentary canal contents and thus represented bio-accumulation. In the second group, the concentrations of five elements (Fe, Cu, Ba, Sr and Ni) showed no significant difference in concentrations of trace elements between the organic tissue and alimentary canal contents. In the third group, the concentrations of Mg, Al, Mn, Rb and Pb were significantly lower in the organic tissue than in the alimentary canal contents. Model results well reflected the disposition of the trace elements detected in the N.lugens. The validity of estimates for model parameters were verified by the bioaccumulation factor from rice plants to N. lugens in paddy fields. Meanwhile the estimation method has the possibility to apply other studies involving metal or metalloid accumulation in other sucking insects, and more objectively assess elements disposition in the insects.