ABSTRACT
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 Nature of Species Structure and Abundance of Predacious
Phytoseiid Mites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 Geographical and Climatic Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 Food Habits and Co-occurring Prey Species . . . . . . . . . . . . . . . . . . . 171 Physical and Chemical Factors of Host Plant. . . . . . . . . . . . . . . . . . . 171 General Pattern of Dominancy in Phytoseiid Fauna. . . . . . . . . . . . . 173
Attributes of Mite Species Commonly Found in Agroecosystems and Factors Affecting their Abundance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
Phytoseiid Fauna in North American Apple Orchards . . . . . . . . . . 176 Pesticide Application as Ultimate and Proximate Factors . . . . . . . . 178 Cultural Practice as Ultimate and Proximate Factors . . . . . . . . . . . . 179 Change in Prey Fauna as a Proximate Factor . . . . . . . . . . . . . . . . . . . 179 Competitive Interaction as an Ultimate Factor . . . . . . . . . . . . . . . . . 180
Use of Natural Enemies in Sustainable Agroecosystems as Concluding Remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
INTRODUCTION
Recent expansion of the integrated pest management (IPM) system has revolutionized the whole concept of crop protection not only in Japan but
also in other areas of the world. Consequently, applied entomologists and fundamental ecologists enjoy unexpected favor at all levels, not only to boost crop yield but also to preserve nature. For a long time, the nature of biotic interactions has been undiscovered and hidden in agricultural lands by heavy use of agrochemicals. Japan, one of the leading producers of these chemicals, unfortunately has taken the lead in throwing them into various facets of agroecosystems, where a rich biotic fauna of the temperate zone was originally established.
