ULTRASTRUCTURE OF SPERMATOZOA IN FOUR SPECIES OF MATSUCOCCUS Two New Species of Parasitoids on Scale Insects on Fruit Tree (Hymenoptera:Encyrtidae) A Study on the Nutriology Promoting the Population Increase of Eulecanium gigantea by Urban Pollution The Ultra-Morphology and Chemical Composition of Waxes Secreted by a Scale Insect Physokermes shanxiensis (Homoptera : Coccidae) Research progress on the chemical ecology of scale insects Comparison analyses of scale insects and functional groups of natural enemy at jujube orchards intercropped with herbage