|Budget Amount *help
¥2,400,000 (Direct Cost : ¥2,400,000)
Fiscal Year 1990 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1989 : ¥1,400,000 (Direct Cost : ¥1,400,000)
Statistical analyses were made to develop efficient monitoring systems for the management of some important insect pest populations based on field census data. For the Brown Plant Hopper (BPH) attacking rice, the characteristics of spatial distribution in paddy fields were comprehensively described for its Japanese, Philippine and Indonesian populations, and based on these knowledges various statistical techniques for efficient, labor-saving population estimation, were deviced for field surveys. They include techniques such as sequential density estimation, sequential hypothesis test for control decision making, and density estimation by presence/absence sampling, and practical census plans were established specifically for the BPH population management in West Java, Indonesia. Analyses were also made for some coccid pests attacking mandarine orange trees, using the data taken in a nearly unsprayed orange orchard in Wakayama Prefecture. Detailed information on the between- and within-tree distributions was obtained for the pests such as the arrowhead scale, the red wax scale and the Indian wax scale, and then convenient census techniques based on the easy "grading" rather than precise evaluation of population density was developed for practical use. Apart from these analyses for usual crop pests, a simple sequential test based on the succession of 'zero's or uninfested sampling units is proposed for use in verifying zero-infestation in specific pest control surveys as in eradiiation projects, which can be applicable efficiently to both finite and infinite populations.