| dc.description.abstract | The purpose of this study was to determine the types of pests found in rice field ecosystems that use chemical, organic pesticides and control in the vegetative and generative phases. The method used in this study is purpossive sampling with direct data collection techniques on farmers' land at different locations at a number of observation points.Phases taken using 3 traps, namely Core Sampler, Sweep Net, and Yellow Sticky Trap. Then the samples collected, taken and identified at the Pest Laboratory, Faculty of Agriculture, University of Sumatera Utara. The parameters observed were Absolute Density (AD), Relative Density (RD), Absolute Frequency (AF), Relative Frequency (RF), species richness index, evenness index, and diversity index. Physical factors such as rainfall, temperature, humidity, light intensity and wind speed were measures. From the research results showed the rice-field without treatment (control) has a total of AD (2,384 individuals) and AF of 229 individuals. Meanwhile, used of organic pesticide resulted AD (2,234 individuals), AF (236 individuals) compared to apply pesticide (AD=1,808 individuals AF is 165). The richness score from three types of treatments into higher category (R=0.85). The diversity value (H') of insect pests in the rice fields is in the medium category (H'=2.5-3.0), while the evenness index (E'=0.31-0.40). The dominant pests found are, Chironomus, Leptocorisa, Pomacea, Tipulla, Chilo, Oxya, Pomacea, Leptispa, Schotonphora, Cnaphalocrocis. | en_US |
