DISTRIBUSI SPASIAL, RESPONS NUMERIK, DAN AGREGASI Paederus fuscipes SEBAGAI PREDATOR Nilaparvata lugens DI SAWAH

ISMI RINARTI, Prof. Dr. Ir. FX. Wagiman, S.U.

2013 | Skripsi | ILMU HAMA & PENYAKIT TUMBUHAN

Penelitian bertujuan untuk menganalisis dan mendeskripsi cemiri ekologi predator Tomcat (Paederus fuscipes) dalam interaksinya dengan mangsa wereng batang cokelat (Nilaparvata lugens), antara lain meliputi aspek: distribusi spasial predator (P. fuscipes) dan mangsa (N. lugens), respon numerik predator terhadap mangsa di sawah, dan agregasi predator pada rumpun padi dengan populasi mangsa yang tinggi. Penelitian ini dilaksanakan pada bulan Oktober sampai Desember 2012 di daerah Sido Agung, Godean, Sleman, Daerah Istimewa Yogyakarta, sejak pra tanam sampai stadia masak susu. Pitfall trap sebanyak 36 unit dipasang secara acak sistematis selama 24 jam di pematang sawah sebelum tanam untuk menangkap predator. Pada enam petak persemaian dilakukan pengamatan in situ terhadap P. fuscipes dan N. lugens pada lima titik pengamatan yang diambil secara acak. Pengamatan predator dan mangsa pada pertanaman umur 7, 14, 21, dan 30 HST, bunting, berbunga, dan masak susu, pada sampel sebanyak 100 rumpun, yang diambil secara acak. Hasil analisis menunjukkan bahwa P. fuscipes tidak ditemukan pada pematang sawah sebelum tanam, tetapi baik predator ini maupun wereng ditemukan pada pertanaman padi. Pola distribusi predator di persemaian dan pertanaman adalah seragam. Pola distribusi N. lugens di persemaian adalah acak, pada pertanaman 7, 14, dan 21 HST, bunting, dan berbunga adalah seragam, sedangkan pada 30 HST dan masak susu adalah mengelompok. Predator P. fuscipes di sawah menunjukkan respons numerik yang sangat kuat terhadap N. lugens ditunjukan oleh nilai korelasi R = 0.832, dan tidak menunjukkan agregasi pada rumpun padi dengan kepadatan populasi N. lugens tertinggi.

The purpose of this research is to analyze and describe the ecological characteristics of predatory rove beetle (Paederus fuscipes) in its interaction with brown plant hopper (Nilaparvata lugens), comprised of their spatial distribution, the numerical response of the predator against its prey in rice field, and aggregation of the predator on rice hill with a highest population of prey in the rice field. The research was conducted in October until December 2012 in Sido Agung, Godean, Sleman, Yogyakarta, from pre-planting to milky stage. Pitfall traps as many as 36 units were placed at systematic random for 24 hours before planting in the rice field bund to catch the predators. In six seedbeds, the P. fuscipes and N. lugens were counted in situ at five-point, which were taken. At random observations of the predator and prey was conducted on 100 rice hills at 7, 14, 21, 30 days after transplanting (DAT), primordia, flowering, and milky stages. The rice hills were taken at random. Results showed that the P. fuscipes did not found in the rice fields at pre-planting, however the predator and brown plant hopper were found in the rice plantations. Distribution pattern of the predator in the seedbeds and in the rice plantations was uniform. Distribution pattern of the N. lugens in the seedbed was random, while in the rice at 7, 14, 21 DAT, primordia, and flowering were uniform, and at 30 DAT and milky stage were clumped. The P. fuscipes in the rice field showed a very strong numerical response against N. lugens as indicated by the correlation R = 0.832, and it did not showed aggregation on the rice hill with the highest population density of N. lugens.

Kata Kunci : Distribusi spasial, Respons numerik, Agregasi, Paederus fuscipes, Nilaparvata lugens