Judul: Population Dynamics of Rice Bug Leptocorisa oratorius (F.) on Rice Field in Sidomulyo Village, Pangandaran Regency.
Abstrak: Tanaman padi (Oryza sativa L.) merupakan salah satu tanaman pangan utama di Indonesia. Hama menjadi salah satu faktor pembatas dalam peningkatan produksi padi. Penelitian ini bertujuan mengetahui dinamika populasi walang sangit Leptocorisa oratorius pada pertanaman padi di Desa Sidomulyo, Kabupaten Pangandaran, Jawa Barat. Pengamatan walang sangit dilakukan di lahan milik petani di Desa Sidomulyo, Pangandaran. Penelitian dilakukan di lahan padi seluas ± 560 m2. Pengamatan dilakukan secara langsung pada tanaman contoh. Data yang diperoleh dari hasil pengamatan dan hasil identifikasi diolah menggunakan Microsoft Office Excel 2010, kemudian ditampilkan dalam bentuk tabel. Data hasil pengamatan menunjukkan imago walang sangit mulai ditemukan pada pertanaman padi umur 56 HST dengan nilai rata-rata sebesar 3,67 ± 2,32 ekor. Nimfa kecil pada umur 63 HST dengan nilai rata-rata 2,13 ± 2,17 ekor dan nimfa besar pada umur 66 HST dengan nilai rata-rata 1,33 ± 1,35 ekor. Secara keseluruhan puncak populasi imago, nimfa kecil, dan nimfa besar terjadi pada umur 87 HST masing-masing sebesar 27,07 ± 3,10 (imago), 20,40 ± 3,29 (nimfa kecil), dan 28,33 ± 3,64 (nimfa besar). Proporsi imago tertinggi terjadi pada umur tanaman 56 HST yaitu sebesar 100%. Tingkat kerusakan bulir padi akibat serangan walang sangit mencapai 29,02%. Musuh alami yang ditemukan di pertanaman yaitu dari kelompok predator yang meliputi Pardosa pseudoannulata, Oxyopes sp., Andrallus spinidens, dan Paederus fuscipes. Kata kunci : musuh alami, struktur umur, tanaman padi, walang sangit, Rice (Oryza sativa L.) is one of the main food crops in Indonesia. Pests are one of the limiting factors in increasing rice production. This study aims to determine the population dynamics of the Leptocorisa oratorius in Sidomulyo Village, Pangandaran Regency, West Java. Observations of rice bug were carried out on farmer's land in Sidomulyo Village, Pangandaran. The study was conducted on an area of ± 560 m2. Observations were made directly on sample plants. The data obtained from observations and identification results were processed using Microsoft Office Excel 2010, then displayed as tables. Data from the observation showed that rice bug were found at 56 DAP age of rice planting with an average value of 3.67 ± 2.32 individuals. Small nymphs at 63 DAP with an average value of 2.13 ± 2.17 and large nymphs at 66 DAP with an average value of 1.33 ± 1.35. Overall the peak population of adult, small nymph, and large nymph occurred at the age of 87 DAP, respectively 27.07 ± 3.10 (adult), 20.40 ± 3.29 (small nymph), and 28.33 ± 3 .64 (large nymph). The highest proportion of adults occurred at the age of 56 DAP which was 100%. The level of damage to rice grains due to attacks by the rice bug reached 29.02%. The natural enemies found in the plantations were from a group of predators which included Pardosa pseudoannulata, Oxyopes sp., Andrallus spinidens, and Paederus fuscipes. Keywords: age structure, natural enemies, rice plants, rice bugs
Keyword: age structure, natural enemies, rice plants, rice bugs

Judul: Population Abundance of Rice Pests and Predators in the Jajar Legowo and Conventional Planting System in Baregbeg Village, Lakbok District, Ciamis Regency
Abstrak: Padi (Oryza sativa L.) merupakan salah satu tanaman pangan penting di Indonesia. Hama menjadi salah satu faktor pembatas dalam peningkatan produksi padi. Penelitian ini bertujuan untuk memperoleh informasi kelimpahan populasi hama pada pertanaman padi dengan sistem tanam jajar legowo dan konvensional di Desa Baregbeg, Kecamatan Lakbok, Kabupaten Ciamis, Jawa Barat. Penentuan tanaman contoh dilakukan dengan metode sampling diagonal pada empat subpetak dalam setiap petak pengamatan. Populasi hama dan musuh alami diamati mulai umur tanaman 3 minggu setelah tanam (MST) sampai 12 MST dengan interval satu minggu. Hama yang ditemukan pada sistem tanam jajar legowo dan konvensional adalah wereng batang cokelat (Nilaparvata lugens), keong mas (Pomacea canaliculata) dan walang sangit (Leptocorisa oratorius). Sedangkan predator yang ditemukan pada kedua sistem tanam adalah laba-laba serigala (Pardosa pseudoannulata) (Lycosidae) dan kumbang jelajah (Paederus fuscipes) (Staphylinidae). Secara umum kelimpahan hama pada kedua sistem tanam relatif rendah, namun ada kecenderungan populasi hama pada sistem tanam jajar legowo lebih rendah dibandingkan konvensional., Rice (Oryza sativa L) is one of the main food crop commodities in Indonesia. Plant pests are limiting factor in increasing crop production. This study aimed to get information pests population in rice cultivation using the legowo and conventional planting system in Baregbeg Village, Lakbok District, Ciamis Regency, West Java. The determination of the sample plants was carried out using a diagonal sampling method with four subplots in each plot. Pests and natural enemy populations were observed from the age of 3 weeks after planting (WAP) to 12 WAP with one week intervals. Pests found in the jajar legowo and conventional cropping systems were the brown planthoppers (Nilaparvata lugens), the golden snail (Pomacea canaliculate) and the rice bug (Leptocorisa oratorius). While the predators found in both cropping systems were the wolf spiders Pardosa pseudoannulata (Lycosidae) and the rove beetles Paederus fuscipes (Staphylinidae). In the general, the abundance of pests population in both planting system was relatively low, but there was a tendency for the pest population in the jajar legowo planting system to be lower than conventional.
Keyword: hama, populasi, predator, sistem tanam jajar legowo

Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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