[Mercury contents and distribution characteristics in cicadae]

Total mercury contents of cicadae bodies, wings and exuviaes were studied in Huludao City to discuss mercury distribution characteristics in cicadae and to reveal the environmental mercury accumulation effects in the long life-cycle insects through comparing cicadae with other insect species. The average mercury contents of cicadae bodies were 2. 64 mg x kg(-1) and much higher than those in the contrast sites (1.00 mg x kg(-1) on average) in Huludao City. Mercury contents were found in the order of cicadae bodies > wings (0.98 mg x kg(-1) on average) > exuviaes (0.50 mg x kg(-1) on average). Sex differences of mercury contents and body weights of cicadae were significantly great. The females had larger body weights (1.11 g on average) and lower mercury contents (1.34 mg x kg(-1) on average) than the males (body weight: 0.54 g on average; mercury contents: 3.38 mg x kg(-1) on average), respectively. Mercury contents of cicada's bodies varied greatly with sample sites, mercury contents of wings changed little. No significant correlation was found between mercury contents of soil and cicadae bodies. Mercury contents of cicadae were lower than those of dragonflies, higher than those of other insects with shorter life-cycle periods and it reflected the accumulation effects of environmental mercury in the long life-cycle insects such as cicadae.