THE EFFECT OF AIR POLLUTION ON SOPHORA JAPONICA (LEGUMINOSAE) AND EULECANIUM GIGANTEUM (SHINJI) (HEMIPTERA: COCCOIDEA: COCCIDAE) IN URBAN AREAS IN CHINA

Abstract

THE EFFECT OF AIR POLLUTION ON SOPHORA JAPONICA (LEGUMINOSAE) AND EULECANIUM GIGANTEUM (SHINJI) (HEMIPTERA: COCCOIDEA: COCCIDAE) IN URBAN AREAS IN CHINA.

A study was made of the effect of two air pollutants (sulphur dioxide and lead) on the pest status of the soft scale Eulecanium giganteum (Shinji) and on the accumulation of sulphur and lead in the scale’s host tree, Sophora japonica, in three cities in China, namely Taiyuan, Yuci and Taigu. E. giganteum is a major pest of several tree species in many cities in China where air pollution can be high. This study showed a positive correlation between the level of the pollutants in the trees and the populations of the scale. The leaves absorbed and accumulated a greater amount of sulphur dioxide (SO2 - as sulphur) and lead (Pb) than the twigs, but the trends were the same in each, namely with high levels in these tissues in the Spring and early Autumn. It is concluded that E. giganteum can withstand high levels of pollutants, both within the host plant and in the environment, whereas its natural enemies may not.

Key words: urban areas, biology, percentage parasitism, sap quality, pollution levels, Beijing utila, Microterys clauseni, Blastothrix sericea, Eucomys sasakii, Anisetus, Coccinellidae, Helicodinidae, Encyrtidae, Coccinella septempunctata, Harmonia axyridis, Chilocorus rubidus.