HABITAT SELECTION, DISTRIBUTION, AND ABUNDANCE OF PARASTRACHIA-JAPONENSIS (HEMIPTERA, CYDNIDAE) AND ITS HOST TREE

Distribution and abundance of the gregarious shield bug, Parastrachia japoncesis Scott, and its host tree, Schoepfia jasminodora Sieb et Zuc c. (Rosidae: Santales), were investigated at Hinokuma Mountain Prefect ural Park, a natural secondary forest in Saga, Japan. Subpopulations o f P. japonensis and host trees were scatter ed throughout the study si te, and each subpopulation invariably had at least 1 fruit-bearing hos t tree within 10 m. Subpopulations ranged from just 15 to > 10,000 ins ects. In addition, we determined the environmental attributes used by P. japonensis to discriminate habitat: and how those characters influe nce its abundance. Resource availability, surrounding bush (for aggreg ating), dark shade, leaf litter quantity and quality (for nesting), an d a sloping area (for drainage during rainy season) were all prominent factors in determining habitat suitability to P. japonensis. Among th ese, the single most determinant attribute with regard to abundance wa s the cumulative food resource availability. Further; 2 attributes tha t are important during nesting, specifically, leaf litter quality and slope, also directly affected abundance of P. japonensis. Apparently c onsistent, particularly good environmental conditions in an area where the cumulative resource availability is also abundant favor formation of large subpopulations. The findings help explain why the habitat of P. japonensis is so strictly limited to tile type of diverse, early s tage forest investigated here.