Populations of Rice Grain Bug, Paraeuscosmetus pallicomis, (Hemiptera: Lygaeidae) in Weed-free Paddy Field, Weedy Paddy Field, and Paddy Dykes

摘要

Research on the populations of rice grain bug Paraeuscosmetus pallicomis Dallasud(Hemiptera: Lygaidae) in paddy field ecosystems was performed with the aim to determineudthe populations of rice grain bug in weed-free paddy field, weedy paddy field, and paddyuddykes. Experiment was carried out in the village of Paccellekang in the district of Patallasangudof Gowa Regency in South Sulawesi, Indonesia. Observations were performed during theudmilky grain stage (85 days after planting), the mature grain stage (105 days after planting),udand one day after harvest (115 days after transplanting). Results showed that 85 days afterudthe transplanting, the populations of rice grain bug was significantly higher in the weedyudpaddy field compared to weed-free field and paddy dykes with total numbers of 1.75, 3.53,udand 0.31 insects per 2 hills, respectively. Similarly, 105 days after the transplanting, 2.53,ud5.53, and 0.11 insects per hill, respectively. However, one day after the harvest (115 daysudafter transplanting) the number of insects in weed-free field decreased, while in the dykesudincreased, and the weedy plot still had the highest number of insects per 2 hills. Our resultsudsuggested that weeds played an important role in regulating the bug population by providingudalternative shelter and foods for the insect.