Judul: Population Dynamics of Brown Planthopper, Nilaparvata lugens Stål. and their Natural Enemies in Rice plants at Tamansari and Ciampea Subdistricts, Bogor Regency
Abstrak: Wereng batang coklat (WBC) merupakan salah satu hama utama tanaman padi. Musuh alami dari golongan predator maupun cendawan memiliki peran penting dalam mengendalikan populasi WBC. Penelitian ini bertujuan untuk memperoleh informasi tambahan terkait dinamika populasi WBC serta musuh alaminya di Kecamatan Tamansari dan Ciampea. Penelitian dilakukan dari bulan Februari hingga Mei tahun 2021 di Desa Sukaresmi dan Desa Pasir Eurih (Kecamatan Tamansari) serta Desa Bojong Jengkol (Kecamatan Ciampea). Hasil penelitian menunjukan nimfa WBC sudah ditemukan pada padi berumur 4 minggu setelah tanam (MST). Puncak populasi WBC di Kecamatan Tamansari terjadi pada fase vegetatif padi, sedangkan di Kecamatan Ciampea populasi WBC masih banyak ditemukan pada fase generatif padi. Kepadatan populasi WBC tertinggi terjadi pada padi berumur 9 MST di Desa Bojong Jengkol. Keanekaragam musuh alami di ketiga desa menurut perhitungan uji dari Shannon-Wiener berada di tingkat sedang. Terdapat 9 macam jenis musuh alami yang ditemukan dari ketiga desa. Tiga jenis predator yang paling banyak ditemui antara lain: Lycosa pseudoannulata, Cyrtorhinus lividipennis dan Paederus fuscipes. Selain itu ditemukan juga dua jenis cendawan antara lain: Hirsutella citriformis dan Beauveria bassiana., Brown planthopper, N. lugens (BPH) is one of the main pests of rice plants. Natural enemies such as predators and entomopathogenic fungi have an important role in controlling the BPH population. This study aims to obtain information related to the population dynamics of BPH and its natural enemies in Tamansari and Ciampea Sub-districts. This research was conducted from February to May in Sukaresmi Village and Pasir Eurih Village (Tamansari District) and Bojong Jengkol Village (Ciampea District). The results showed that BPH nymphs were found in 4 weeks after planting (WAP). The peak population in Tamansari District was in the vegetative phase of rice, while in Ciampea District BPH populations were still mostly found in the generative phase of rice. The highest BPH population density occurred in the village of Bojong Jengkol at 9 WAP. The diversity of natural enemies according to Shannon-Wiener from the three villages is at a moderate level. There are 9 types of natural enemies found from the three villages. The three most common types of predators were: Lycosa pseudoannulata, Cyrtorhinus lividipennis and Paederus fuscipes. And also there are two types of fungi in the field: Hirsutella citriformis and Beauveria bassiana.
Keyword: BPH, population dynamics, natural enemies

Judul: SURVEY OF DISTRIBUTION OF BROWN PLANTHOPPER POPULATION IN RICE CROPS IN SUBANG REGENCY WEST JAVA
Abstrak: Padi (Oryza sativa L.) merupakan komoditas penting sebagai sumber pangan pokok di Indonesia. Budidaya tanaman padi seringkali mengalami kegagalan akibat serangan hama wereng batang cokelat (WBC) Nilaparvata lugens Stål. Penelitian ini bertujuan mengetahui persebaran populasi WBC di Kabupaten Subang, kerapatan populasinya, dan tingkat kerusakan tanaman padi di tiga lokasi ketinggian tempat yang berbeda. Penelitian ini dilakukan dengan menelusuri keberadaan serangan WBC di lahan persawahan di areal kabupaten Subang dan memetakan persebarannya, menentukan lahan perlakuan terinfestasi di tiga lokasi ketinggian tempat berbeda, mengamati tingkat kerusakan tanaman pada umur 4 MST dan kerapatan populasi WBC. Data penunjang diperoleh melalui wawancara terhadap petani tentang teknik budidaya padi setempat kaitannya dengan pengendalian WBC di lahannya. Luas serangan dan intensitas kerusakan tanaman tertinggi 91,5% dan 41%, dengan jumlah populasi WBC tertinggi 1.8 ekor/rumpun ditemukan di lahan padi dataran rendah pada ketinggian 27-38 m dpl, sebaliknya kerusakan paling rendah sebesar 22% dan 4.3% dengan jumlah populasi 0.35 ekor/rumpun ditemukan di dataran tinggi pada 516-526 m dpl. Penggunaan varietas padi Ciherang dan Inpari 31 tidak berpengaruh terhadap jumlah populasi WBC. Lokasi penanaman padi di dataran rendah dengan curah hujan dan suhu lingkungan yang tinggi berkontribusi dalam peningkatan populasi WBC, Rice (Oryza sativa L.) is an important commodity as the staple food in Indonesia. Rice cultivation often fails due to attacks by the brown planthopper (BPH) Nilaparvata lugens Stål. This study aims to determine the distribution of BPH population in Subang Regency, the population density, and the level of damage to rice crops at three different altitude locations. This research was conducted by tracing the presence of BPH infestation in paddy fields in the Subang district area and mapping their distribution, determining the infested treatment areas at three different altitude locations, observing the level of plant damage at 4 WAP and the population density of BPH. Supporting data was obtained through interviews with farmers regarding local rice cultivation techniques in relation to BPH control in their fields. The highest attack area and intensity of crop damage were 91.5% and 41%, with the highest number of BPH populations of 1.8 individuals/hills found in lowland rice fields at an altitude of 27-38 masl, whereas the lowest damage was 22% and 4.3% with the lowest populations of 0.35 individuals/hills found in the highlands at 516-526 masl. Ciherang and Inpari 31 rice varieties had no effect on the number of WBC populations. The location of rice cultivation in the lowlands with high rainfall and ambient temperature contributed to the increase in the BPH population.
Keyword: Intensitas, Ketinggian tempat, Luas serangan, Varietas padi, Altitude, Attack area, Intensity, Rice varieties

Judul: Membran Komposit Kitosan-Zeolit untuk Aplikasi Direct Methanol Fuel Cell
Abstrak: Direct methanol fuel cell (DMFC) is a fuel cell that utilize methanol as the fuel source. The electrolyte membrane used in the DMFC system in this research was chitosan-zeolite composite membrane. The composite membrane was synthesized with chitosan-zeolite composition variation of 1:1, 1:2, 1:3, and 2:1. The membranes were analyzed by Fourier transform infrared spectrophotometer (FTIR) and scanning electron microscope, and for the specific gravity. Membrane performances were tested with methanol uptake, methanol permeability, conductivity, and potential difference in the DMFC system. The FTIR spectrum showed no formation of new functional groups inducating that the composite membrane was a result of physical mixing. Morphological analysis showed that the membrane was nonporous. Chitosan-zeolite 1:3 composite membrane had the highest specific gravity and methanol uptake, 1.4226 g/mL and 41.44%, respectively. The highest proton conductivity was showed by the 1:2 chitosanzeolite composite membrane, namely 7.2946× 10-7 S/cm. Based on this research results, chitosan-zeolite composite membrane can be applied in DMFC system.
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