Impact of rice field development in disease vectors in Indonesia

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Impact of rice field development of disease vectors in Indonesia was investigated with the following hypotheses. Hyposesis 1 : there is an increased probability of vector outbreaks in early phases of rice field development projects when ecosystems are inmmature. Hyposesis 2 : rice field development improves standards of life, thus reduce the probability of being bitten by vectors. Research consists of (1) continual study at rice field development project areas in North Sulawesi and Seram, and (2) comparative study of villages at various stages of rice field development. Main results are as foolows. To understand impact of rice field development more clearly, study of disease vectors in aboriginal villages were included.(1)Many ground pools are produced on open lands produced by deforestation for rice field development, but mosquito outbreaks are prevented by colonization of predacious insects. (2)Newly constructed rice fields are occupied by insect predatoers which prevent mosquito out … More breaks. In some rice fields without predators, anopheline outbreaks were observed. (3)Aboriginal villages have no containers for mosquito-breeding around houses. New transmigration villages have a few containers and older transmigration villages have more containers. Important mosquito habitats in new transmigration villages were stagnant ditches for waste water and pools keeping human excreta. (4)Fauna of latrine flies are richest in the natural forest and aboriginal villages. In new transmigration villages with primitive lavatories, old transmigration villages, and urban areas, only a few introduced species of latrine flies occur at high densities. (5)The house fly is not found in natural forests and its densities increase with years after human settlement. (6)Sepsid flies in transmigration villages consist of species introduced with introduction of domestic animals. (7)Type and abundance of mosquito-breeding habitats in villages with irrigated rice fields are essentially the same as those of villages with rain-fed rice fields, because of the meintenance of traditional living style.The hyposeses were partly justified, but there were also unexpected findings. Continual stude for the all stages of rice field development is necessary. Less