Judul: Joint Action of Emamectin Benzoate and Chlorantraniliprole Insecticides on Fall Armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae)
Abstrak: Spodoptera frugiperda merupakan hama penting pada tanaman jagung, hama ini dapat menyebabkan penurunan produktivitas bahkan kegagalan panen. Umumnya petani mengendalikan S. frugiperda menggunakan insektisida sintetik berbahan aktif tunggal. Penggunaan insektisida berbahan aktif tungggal dapat mempercepat timbulnya resistensi. Penelitian ini bertujuan mempelajari kerja bersama insektisida emamektin benzoat dan klorantraniliprol terhadap larva S. frugiperda pada tanaman jagung. Metode uji yang digunakan adalah celup daun dengan lima ulangan. Mortalitas serangga diamati pada 24, 48, dan 72 jam setelah perlakuan. Setiap data kematian pada uji toksisitas tunggal atau campuran dihitung menggunakan analisis probit. Sifat aktivitas campuran insektisida ditentukan dengan menghitung indeks kombinasi masing-masing bahan aktif dalam campuran pada tingkat LC50 dan LC95. Hasil penelitian menunjukkan bahwa nilai LC50 dan LC95 pada perlakuan emamektin benzoat berturut-turut sebesar 0,0017 dan 0,023 ppm bahan aktif (b.a), dan nilai LC50 dan LC95 pada perlakuan klorantraniliprol berturut-turut sebesar 0,091 dan 0,690 ppm b.a. Toksisitas insektisida campuran emamektin benzoat dan klorantraniliprol dengan nisbah 2:1 bersifat sinergistik kuat. Dengan demikian, penggunaan insektisida campuran emamektin benzoat dan klorantraniliprol dengan nisbah 2:1 dapat digunakan untuk mengendalikan larva S. frugiperda., Spodoptera frugiperda is an important pest in corn plants. The attack of this pest can decrease the corn productivity. Commonly, farmers use synthetic insecticides to control S. frugiperda with single active ingredient. The continuous use of synthetic insecticides with single active ingredient can speed the insect resistance occurance including to S. frugiperda. The use of synergistic active ingredents (a.i) of insecticide is an alternative to delay the resistance occurance. This research aimed to study the joint action of emamectin benzoate and chlorantraniliprole insecticides against the fall armyworm S. frugiperda. The test method used was leaf dipping with five replications. The insect mortality was recorded at 24, 48, and 72 hours after treatment. Mortality data from single or mixed toxicity tests were calculated using probit analysis to get LC50 and LC95 values. The joint actions of the insecticide mixture were determined by calculating the combination index of each active ingredient in the mixture solution at the level LC50 and LC95. The LC50 and LC95 values of emamectin benzoate were 0.0017 and 0.023 ppm a.i. While, the LC50 and LC95 values of chlorantraniliprole were 0.091 and 0.690 ppm a.i. The joint action of emamectin benzoate and chlorantraniliprole mixture at ratio of 2:1 shows strong synergistic. Therefore, the use of a mixture of emamectin benzoate and chlorantraniliprole at ratio 2:1 can be used an alternative means to control S. frugiperda larvae.
Keyword: LC50, hama jagung, insektisida campuran, LC95, sinergistik

Judul: Effectiveness of the Entomopathogenic Fungi Metarhizium spp. on The Fall Armyworm, Spodoptera frugiperda Smith (Lepidoptera: Noctuidae)
Abstrak: Ulat grayak jagung, Spodoptera frugiperda merupakan hama invasif yang menjadi ancaman serius bagi produksi jagung di Indonesia. Salah satu pengendalian alternatif sebagai upaya mengurangi penggunaan pestisida sintetik dengan memanfaatkan cendawan entomopatogen. Penelitian ini bertujuan untuk mengetahui keefektifan cendawan entomopatogen Metarhizium anisopliae dan M. robertsii terhadap mortalitas larva S. frugiperda. Lima tingkat kerapatan konidia yaitu 106 , 107 , 108 , 109 konidia/mL, dan kontrol diaplikasikan dengan metode semprot pada larva instar ketiga S. frugiperda. Mortalitas diamati setiap hari hingga delapan hari setelah aplikasi. Berdasarkan hasil pengujian, nilai LC50 pada M. anisopliae sebesar 3,22 x 108 konidia/mL dan M. robertsii sebesar 2,60 x 107 konidia/mL. Mortalitas S. fugiperda tertinggi terjadi pada perlakuan M. anisopliae dan M. robertsii terjadi pada perlakuan 109 konidia/mL sebesar 82 dan 100% dengan nilai LT50 berturut-turut 2,96 dan 1,82 hari. Kedua cendawan ini bersifat patogenik dan efektif terhadap S. frugiperda. Selain itu, cendawan entomopatogen M. robertsii lebih virulen terhadap larva S. frugiperda dibandingkan dengan M. anisopliae., The fall armyworm, Spodoptera frugiperda is an invasive pest that poses a serious threat to corn production in Indonesia. One alternative control method to reduce the use of synthetic pesticides is utilizing entomopathogenic fungi. This research aimed to study the effectiveness of the entomopathogenic fungi Metarhizium anisopliae and M. robertsii on the mortality of S. frugiperda larvae. Five levels of conidia density: 106 , 107 , 108 , 109 conidia/mL, and an untreated were spray-applied to third instar larvae of S. frugiperda. Insect mortality was observed daily for eight days after treatment. Based on the result, the LC50 value for M. anisopliae was 3.22 x 108 conidia/mL while for M. robertsii, it was 2.60 x 107 conidia/mL. The highest insect mortality M. anisopliae and M. robertsii treatments occurred at 109 conidia/mL by 82 and 100%, respectively. The value of LT50 values were 2.96 and 1.82 days, respectively. Both M. anisopliae and M. robertsii were entomopathogenic and effective to control S. frugiperda. Additionally, M. robertsii was more virulent to S. frugiperda larvae than those of M. anisopliae.
Keyword: biological agents, M. anisopliae, M. robertsii, virulence

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology