The population of green leafhopper Nephotettix sp. from seedling until to the end of the vegetative phase needs to be controlled to avoid the incidence of tungro. Integrated pest management based on bioecological management of natural enemies has the potential to sustainable agroecosystems. The purpose of the study was to find out the population dynamics of green leafhopper and various species of predators on several rice varieties. Field study was conducted in a rainy season of 2013 at The Tungro Disease Research Station (Tundres), Lanrang, South Sulawesi. Observational methods were used to study development of the green leafhoppers population and their predators in five rice varieties: Inpari 4, Inpari 7, Inpari 9, IR 64, and TN1. The results showed that the population density of green leafhoppers increased during the vegetative stage and decreased in the generative stage. It was not affected by the resistance of varieties. Generally, the predators population density did not follow their prey. Shannon-Wienner (H’) diversity index of predators showed up to 0.91. It suggested that identifying predator functional traits improve opportunities of the practice of conservation biological control.Keywords: green leafhopper, population, predators, rice varietiesINTISARIPopulasi wereng hijau Nephotettix sp. sejak persemaian hingga akhir fase vegetatif perlu dipantau dan dikendalikan untuk menghindari dan menekan insidensi tungro. Pengendalian hama terpadu yang berbasis bioekologi dengan menekan penggunaan pestisida, kesesuaian varietas dan pengelolaan musuh alami mempunyai potensi dalam membangun agroekosistem yang berkelanjutan. Tujuan penelitian ini adalah untuk mengetahui pola perkembangan populasi wereng hijau dan berbagai jenis predatornya pada beberapa varietas padi sehingga menjadi informasi penting dalam penentuan jenis dan proporsi varietas, pemantauan kepadatan populasi wereng hijau dalam kaitannya dengan insidensi tungro. Penelitian dilaksanakan di kebun percobaan Loka Penelitian Penyakit Tungro, Lanrang, Sulawesi Selatan pada musim hujan 2013, dengan mengunakan metode observasi untuk mengetahui keberadaan dan perkembangan populasi wereng hijau dan predatornya pada lima varietas padi yang berbeda umur (kegenjahan) dan ketahanannya terhadap wereng hijau, yaitu Inpari 4, Inpari 7, Inpari 9, IR 64, TN1. Hasil penelitian menunjukkan bahwa pola populasi wereng hijau meningkat selama fase vegetatif (tiga hingga enam MST) dan menurun pada fase generatif (tujuh hingga delapan MST). Tingkat kepadatan populasi wereng hijau tidak dipengaruhi oleh ketahanan varietas. Secara umum, pola fluktuasi kepadatan populasi predator tidak mengikuti pola fluktuasi kepadatan populasi wereng hijau di setiap varietas. Berdasarkan nilai indeks Shannon-wiener, keragaman predator berada diatas nilai indek 0,91 menunjukkan peluang konservasi musuh alami dalam pengendalian biologis dengan memfokuskan identifikasi tanggap fungsional predator terhadap hama sasaran.Kata kunci: populasi, predator, varietas padi, wereng hijau

Penggunaan pestisida pada produk pertanian semakin mengkhawatirkan, oleh karena itu  dimasa yang akan datang diprioritaskan produk pertanian yang bebas pestisida. Salah satu produk pertanian yang banyak menggunakan aplikasi pestisida adalah tanaman padi. Tanpa aplikasi pestisida secara alami di alam, selalu ada faktor pembatas yang dapat menyeimbangkan ekosistem, salah satunya adalah musuh alami yang dapat menekan perkembangan populasi hama. Tujuan dari penelitian ini adalah untuk mengetahui keanekaragaman hama dan musuh alami pada lahan sawah tanpa aplikasi pestisida selama 1 tahun. Penelitian ini dilakukan di Kebun Percobaan Loka Penelitian Penyakit Tungro, Lanrang Sidrap, Sulawesi Selatan dalam waktu sepanjang tahun  2018. Metode pengamatan adalah monitoring secara berkala setiap minggu menggunakan jaring serangga. Hasil penelitian menunjukkan bahwa rerata populasi hama tertinggi adalah Ulat Grayak (Lepidoptera : Noctuidae), rerata populasi musuh alami tertinggi adalah Kumbang Koksi (Coleoptera : Coccinellidae), rerata populasi parasitoid tertinggi adalah Lalat Tachnidae (Diptera : Tachnidae) dan indeks keanekaragaman (H’) tergolong sedang (2.463) yang menunjukkan bahwa kondisi ekosistem sawah tergolong stabil dan musuh alami masih bisa mengendalikan populasi hama.

Nephotettix virescens is the most effective vector for transmitting tungro disease to rice plants. Two different viral particles cause Tungro transmission. Disease control was often not anticipated in the field, especially when planting is asynchronous, that cause been detected lately. At the cellular level, vector interactions with viruses indicate vector proteins response to viral in the body of vector insects which involved in virus transmission in plants. This study aims to describe the relationship between the differentiation of N. virescens vector protein profiles on the types of tungro symptoms resulting from the transmission to develop techniques for early detection and control of the transmission process. The workflow of this study is screening on vector insects to obtain protein candidates thought to have a role in tungro transmission that had never been previously reported. The results of this study suggested that proteins with estimated molecular weights of 132, 73, and 49 kDa are candidates for proteins that can be used for screening purposes or virulent vector tracing as an early warning alternative to control tungro disease in endemic areas.

ABSTRAK

The epidemiological aspect including monitoring is a critical component of implementing an early warning system. The tungro epidemic in rice is influenced by the population dynamics of the green leafhopper vector. Likewise, rainfall and biotic factors affect the abundance of green leafhopper vectors. Long-term data are essential to explain that mechanism, so population predictions on a seasonal scale can be obtained accurately. This paper analyses weekly data on catching green leafhoppers and other arthropods in a continuous cropping system from 2013-2019. We utilize the climatic data gathered to assess the impact of climatic conditions on population dynamics. To improve the additive and homoscedasticity of the time series, we transform the data. The data are fitted in a linear model. The results showed that the green leafhopper population affected the incidence of tungro in the field. From January to December, the population dynamics of the green leafhopper can be characterized. It can assist in monthly population forecasting for the following years. Exogenous and endogenous variables, however, still need to be studied more comprehensively to identify any other predictive components that should be incorporated.