Toksisitas Abu Terbang Kayu terhadap Nilaparvata Lugens dan Kompleks Predatornya

The brown planthopper (Nilaparvata lugens) is currently a very noxious pest insect and it threatened the self sufficience of rice in Indonesia. Innovation of control technology is urgently needed to be developed. Objective of the study was to determine mortality-effect of the wood fly-ash obtained from pulp factory in Riau against N. lugens and its predator complex. A bioassay of the wood fly-ash was done in the laboratory to determine its activity against the test insects. A randomized complete block design (RCBD) experiment with three treatments —fly-ash 40 kg/ha, botanical insecticide containing of root extract of Derris eliptica, and control— with five replications was conducted at a paddy field in Sleman District Yogyakarta. Results showed that the wood fly-ash was toxic against N. lugens: LD50 at 72 hours after treatment were 4.84 and 43.26 g/m2, respectively. As compared with control and botanical insecticide of D. eliptica, the wood fly-ash was significantly more effective for controlling the N. lugens but relatively safe against predator complex. Dusting of the wood fly-ash at rate of 40 kg/ha effectively reduced population of N. lugens within 2 days but did not significantly reduce population of the predator complex namely spiders (Lycosa sp., Oxyopes sp., Callitrichia sp., Argiope sp., and Tetragnatha sp.), Coccinellidae (Menochilus sexmaculatus and Verania sp.), Cicindelidae (Ophionea sp.), and Staphylinidae (Paederus fuscipes). Wereng batang padi cokelat (Nilaparvata lugens Stal.) merupakan hama utama pada tanaman padi yang paling membahayakan dan sulit dikendalikan sehingga sangat merugikan perpadian di Indonesia. Inovasi teknologi pengendalian mendesak untuk dikembangkan. Tujuan dari penelitian ini adalah menentukan efek mortalitas dari abu terbang kayu yang berasal dari pabrik pulp di Riau terhadap hama N. lugens dan kompleks predatornya. Pengujian dari abu lterbang kayu dilakukan di laboratorium untuk menentukan toksisitas abu terbang kayu terhadap serangga uji. Percobaan menggunakan randomized complete block design (RCBD) dengan 3 perlakuan—dosis abu terbang kayu 40 kg/ha, insektisida botani berasal dari ekstrak akar Derris eliptica, dan kontrol—, dengan 5 ulangan yang dilakukan pada pertanaman padi di Kabupaten Sleman Yogyakarta. Hasil penelitian menunjukkan bahwa toksisitas abu terbang kayu terhadap N. lugens: LD50 setelah 72 jam perlakuan adalah 4,84 dan 43,26 g/m2, berturut-turut. Abu terbang kayu dibandingkan dengan kontrol dan insektisida botani, signifikan dan efektif mengendalikan N. lugens dan relatif tidak membahayakan terhadap kompleks predator. Pemaparan abu terbang kayu dosis 40 kg/ha efektif mengurangi populasi N. lugens selama 2 hari dan tidak signifikan terhadap pengurangan populasi kompleks predator laba-laba (Lycosa sp., Oxyopes sp., Callitrichia sp., Argiope sp., dan Tetragnatha sp.), Coccinellidae (Menochilus sexmaculatus and Verania sp.), Cicindelidae (Ophionea sp.), dan Staphylinidae (Paederus fuscipes