Electronic Theses and Dissertation

Tanaman jagung (zea mays l.) merupakan komoditas pangan strategis yang berperan penting dalam ketahanan pangan nasional dan industri pakan ternak. namun, produktivitas jagung sering mengalami penurunan akibat serangan hama invasif spodoptera frugiperda j.e. smith (lepidoptera: noctuidae) yang dapat merusak daun, titik tumbuh, hingga tongkol jagung. serangan berat dapat menurunkan hasil panen hingga 50–70% bahkan menyebabkan gagal panen. pengendalian yang umum dilakukan petani menggunakan insektisida kimia sintetik secara intensif berpotensi menimbulkan resistensi hama, resurjensi hama sekunder, pencemaran lingkungan, serta risiko kesehatan manusia. oleh karena itu, diperlukan alternatif pengendalian yang lebih ramah lingkungan, salah satunya melalui pemanfaatan cendawan entomopatogen beauveria bassiana (bals.) vuill. cendawan ini mampu menginfeksi serangga melalui kutikula, menghasilkan toksin seperti beauvericin, serta bersifat selektif terhadap musuh alami. penelitian ini bertujuan untuk menguji efektivitas berbagai kerapatan konidia b. bassiana dalam mengendalikan larva s. frugiperda pada tanaman jagung. penelitian dilaksanakan mulai juli 2025 hingga januari 2026 di laboratorium ilmu hama tumbuhan, laboratorium ilmu penyakit tumbuhan, serta lahan percobaan uptd bbhtpp saree, kabupaten aceh besar. rancangan yang digunakan adalah rancangan acak lengkap (ral) non-faktorial dengan lima perlakuan dan empat ulangan. perlakuan terdiri atas kontrol (tanpa aplikasi) serta kerapatan konidia 10⁷, 10⁸, 10⁹, dan 10¹⁰ konidia/ml. larva uji yang digunakan adalah instar iii hasil pembiakan laboratorium. aplikasi dilakukan dengan menyemprotkan suspensi konidia sebanyak 15 ml per tanaman jagung umur 14 hari setelah tanam, kemudian tanaman disungkup dengan kain kasa. parameter yang diamati meliputi masa inkubasi (jam), gejala infeksi, mortalitas larva (%), rata-rata waktu kematian (hari), serta tingkat kerusakan daun jagung (%). data dianalisis menggunakan sidik ragam (anova) dan uji lanjut bnt pada taraf α = 0,05. hasil penelitian menunjukkan bahwa peningkatan kerapatan konidia b. bassiana berpengaruh sangat nyata terhadap seluruh parameter yang diamati. perlakuan kerapatan konidia tertinggi (10¹⁰ konidia/ml) menghasilkan masa inkubasi b. bassiana terhadap s. frugiperda tercepat (33,82 jam), berbeda nyata dengan kerapatan 10⁷ dan 10⁸ konidia/ml. gejala infeksi yang muncul pada larva s. frugiperda meliputi penurunan aktivitas makan, perubahan warna tubuh menjadi hitam, dan pada tahap lanjut tubuh larva tertutup miselium putih. mortalitas larva tertinggi pada 5 hari setelah aplikasi dicapai oleh perlakuan 10¹⁰ konidia/ml sebesar 96,88%, diikuti 10⁹ (84,38%), 10⁸ (62,50%), 10⁷ (50,00%), dan kontrol (15,63%). rata-rata waktu kematian larva s. frugiperda tercepat diperoleh pada kerapatan 10¹⁰ konidia/ml yaitu 2,41 hari, sedangkan kontrol membutuhkan waktu 4,25 hari. tingkat kerusakan daun jagung terendah terdapat pada perlakuan 10¹⁰ konidia/ml (22,50% dengan kategori ringan), sedangkan kontrol menunjukkan kerusakan tertinggi (72,50% kategori berat). dengan demikian, beauveria bassiana pada kerapatan 10¹⁰ konidia/ml sangat efektif sebagai bioinsektisida dalam mengendalikan spodoptera frugiperda dan berpotensi menjadi komponen penting dalam pengendalian hama terpadu pada tanaman jagung.

Maize (Zea mays L.) is a strategic food commodity that plays a vital role in national food security and the livestock feed industry. However, maize productivity often declines due to infestations by the invasive pest Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae), which can damage leaves, growing points, and even the ears of the maize plant. Severe infestations can reduce crop yields by 50–70% or even lead to total crop failure. The common practice of intensive synthetic insecticide application by farmers carries the risk of pest resistance, secondary pest resurgence, environmental pollution, and hazards to human health. Therefore, there is a need for more environmentally friendly control alternatives, such as the use of the entomopathogenic fungus Beauveria bassiana (Bals.) Vuill. This fungus is capable of infecting insects through the cuticle, producing toxins such as beauvericin, and is selective towards natural enemies. This study aims to evaluate the effectiveness of various conidial densities of B. bassiana in controlling S. frugiperda larvae on maize plants. The research was conducted from July 2025 to January 2026 at the Plant Pest Science Laboratory, the Plant Pathology Laboratory, and the experimental fields of UPTD BBHTPP Saree, Aceh Besar Regency. A non-factorial Completely Randomized Design (CRD) was employed, featuring five treatments and four replications. The treatments consisted of a control (no application) and conidial densities of 10⁷, 10⁸, 10⁹, and 10¹⁰ conidia/ml. Third-instar larvae reared in the laboratory were used as test subjects. Application involved spraying 15 ml of conidial suspension onto maize plants 14 days after planting, followed by covering the plants with gauze. Observed parameters included incubation period (hours), infection symptoms, larval mortality (%), mean time to death (days), and maize leaf damage level (%). Data were analyzed using Analysis of Variance (ANOVA) followed by the Least Significant Difference (LSD) test at the α = 0.05 level. The research results indicate that increasing the conidial density of B. bassiana had a highly significant effect on all observed parameters. The highest conidial density treatment (10¹⁰ conidia/ml) resulted in the shortest incubation period of B. bassiana against S. frugiperda (33.82 hours), differing significantly from densities of 10⁷ and 10⁸ conidia/ml. Infection symptoms observed in S. frugiperda larvae included reduced feeding activity, blackening of the body, and—in the advanced stage—the body becoming covered in white mycelium. The highest larval mortality at 5 days post-application was achieved with the 10¹⁰ conidia/ml treatment (96.88%), followed by 10⁹ (84.38%), 10⁸ (62.50%), 10⁷ (50.00%), and the control (15.63%). The fastest mean time to larval death was observed at a density of 10¹⁰ conidia/ml (2.41 days), whereas the control took 4.25 days. The lowest level of maize leaf damage was found in the 10¹⁰ conidia/ml treatment (22.50%, classified as mild), while the control showed the highest damage (72.50%, classified as severe). Thus, Beauveria bassiana at a density of 10¹⁰ conidia/ml is highly effective as a bioinsecticide for controlling Spodoptera frugiperda and has the potential to serve as a key component of integrated pest management in maize crops.