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: Potential of Endophytic Fungi Originated for Rice and Grasses for Controling Brown planthopper Nilaparvata lugens (Stal) (Hemiptera: Delphacidae).
Abstrak: Wereng cokelat adalah hama padi terpenting di Indonesia. Pengendalian wereng cokelat dapat dikembangkan dengan berbagai metode. Cendawan endofit berpotensi sebagai agen biokontrol serangga. Penelitian ini bertujuan mengetahui potensi cendawan endofit dalam mengendalikan wereng cokelat. Cendawan endofit diisolasi dari padi dan rumput-rumputan di sekitar Bogor. Sebanyak 12 isolat hasil isolasi, 7 isolat asal padi dan 5 asal rumput-rumputan. Berdasarkan hasil uji patogenisitas, terdapat 5 isolat adalah nonpatogen. Uji selanjutnya dengan menggunakan 4 isolat cendawan endofit, yaitu Acremonium sp., Nigrospora sp.1, Nigrospora sp.2, Nigrospora sp.3. Penggunaan cendawan Nigrospora sp.4 dari koleksi Klinik Tanaman sebagai kontrol positif. Benih padi direndam ke dalam suspensi konidia cendawan endofit selama dua jam dan diperam selama 24 jam. Bibit padi dipindahkan ke ember setelah tanaman berumur 3 minggu setelah semai. Bibit padi disemprot dengan suspensi cendawan endofit seminggu setelah tanam. Tujuh hari setelah inokulasi cendawan endofit, sebanyak 10 nimfa wereng cokelat instar satu diintroduksi ke tanaman padi dan diamati setiap hari selama 7 hari untuk mencatat kelangsungan hidup nimfa. Dalam percobaan lain, 5 pasang wereng cokelat dewasa diintroduksi ke tanaman padi (28 hari setelah tanam) dan diamati setiap minggunya selama 6 minggu. Semua isolat cendawan endofit yang diuji dalam percobaan ini menyebabkan kematian nimfa dan menurunkan populasi wereng cokelat., Brown planthopper (BPH) is the most important rice pest in Indonesia. We developed many methods to control this planthopper. Endophytic fungi have the potential as biocontrol agents of insects. This study aims to determine the potential of endophytic fungi in controlling BPH. Endophytic fungi were collected from rice and grasses in Bogor. A total of 12 isolates were isolated, 7 from rice and 5 from grasses. Based on test, 5 isolates were nonpathogenic. We used 4 of these isolates for the experiments, Acremonium sp., Nigrospora sp.1, Nigrospora sp.2, Nigrospora sp.3. We also used Nigrospora sp.4 from Klinik Tanaman collection as positive control. Rice seeds were dipped in endophytic conidia fungal suspension for two hours, and then ripened for 24 hours. Rice seedlings were transferred to the planting baskets 3 weeks after sowing. Rice seedlings were sprayed with endophytic fungal suspension a week after planted. Seven days after inoculation of endophytic fungi, 10 first-stage BPH nymphs were introduced and observed daily for 7 days to record nymphs survival. In the other experiment, 5 pairs of adult were introduced in to the rice plants (28 days after treatment) and observed weekly for six weeks. All of endophytic fungi isolates tested in these experiments caused nymphs death and population suppression of BPH.
Keyword: biological control, Nigrospora, population, resistent

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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