Judul: Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) Attacks and Its Parasitoids on Corn Cultivation in Situ Gede Village, West Bogor District, Bogor, West Java
Abstrak: Jagung merupakan tanaman pangan dan bahan baku industri yang penting di Indonesia. Produksi jagung sangat terpengaruh dengan adanya serangan hama invasif baru di Indonesia yaitu ulat grayak jagung (UGJ) atau fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae). Pemanfaatan musuh alami merupakan salah satu metode pengendalian yang dapat digunakan. Penelitian ini bertujuan mengetahui tingkat serangan dan parasitoid S. frugiperda yang ditemukan pada pertanaman jagung di Kelurahan Situ Gede, Kecamatan Bogor Barat, Bogor, Jawa Barat. Pengamatan dilakukan sejak tanaman berumur dua minggu setelah tanam (MST) hingga 10 MST dengan interval dua minggu pada 100 tanaman sampel. Larva S. frugiperda dikumpulkan dari plot sampel lalu dipelihara dan diamati, kemudian parasitoid yang muncul dihitung tingkat parasitisasi dan diidentifikasi. Tingkat serangan UGJ meningkat sejak tanaman jagung berumur dua MST hingga delapan MST dan serangannya konstan hingga 10 MST. Intensitas serangan S. frugiperda tertinggi sebesar 64,40% yang termasuk kategori sangat berat. Parasitoid yang ditemukan yaitu Cotesia sp., Microplitis sp. (Hymenoptera: Braconidae), Charops sp. (Hymenoptera: Ichneumonidae), dan Phoridae (Diptera). Tingkat parasitisasi tertinggi oleh Microplitis sp. sebesar 6,72%., Corn is an important food crop and industrial raw material in Indonesia. Corn productivity is greatly affected by the attack of a new invasive pest in Indonesia, fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae). Using natural enemies is one of the methods to control this pest. This study aimed to determine the plant damages caused by FAW and its natural enemies on corn cultivation at Situ Gede Village, West Bogor District, Bogor, West Java. Observations have been done from two weeks after planting (WAP) to ten WAP with two-week intervals. The plant damage of S. frugiperda was observed on 100 plant samples. The larvae of S. frugiperda were collected from other plant samples and reared in the laboratory until the parasitoids emerged. The parasitoids were then identified. The plant damages increased until the corn cultivation was eight WAP, and the plant damages were constant until harvest. The most severe plant damage of S. frugiperda reached 64.40% and was included in the very heavy category. The parasitoids found during the study were Cotesia sp., Microplitis sp. (Hymenoptera: Braconidae), Charops sp. (Hymenoptera: Ichneumonidae), and Phoridae (Diptera). The highest level of parasitization was Microplitis sp., with 6.72%.
Keyword: fall armyworm, natural enemies, plant damages

Judul: Field Survey of Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae) on Corn Plants at Regency of Bogor, Sukabumi, Cianjur, and Tangerang
Abstrak: Jagung (Zea mays L.) merupakan salah satu komoditas penting setelah beras sebagai sumber karbohidrat dan pakan ternak. Kendala dalam budidaya tanaman jagung salah satunya diakibatkan oleh serangan hama. Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae) merupakan salah satu hama penting pada pertanaman jagung. Sejak tahun 2019 serangga ini adalah spesies invasif di pertanaman jagung Indonesia. Penelitian ini bertujuan untuk mengetahui persebaran hama Spodoptera frugiperda di Kabupaten Bogor, Sukabumi, Cianjur, dan Tangerang. Survei dilakukan di beberapa lokasi pertanaman jagung dengan jumlah yang berbeda di setiap kabupatennya. Survei meliputi pengamatan dan wawancara kepada petani jagung secara langsung. Beberapa larva dari tanaman yang terserang diambil dan diamati sampai fase pupa untuk mengetahui keberadaan patogen atau parasitoid yang berpotensi sebagai musuh alami di lapang. Serangan hama S. frugiperda terjadi pada tanaman jagung di beberapa lokasi di Kabupaten Bogor yang meyerang tanaman jagung, seperti Desa Cibeber dengan luas serangan mencapai 14.5% dan 17.3% di Desa Cisalada. Luas serangan di Desa Cimapak, Kabupaten Sukabumi 16.6% dan 14.3% di Desa Mekarsari, Kabupaten Tangerang. Serangan S. frugiperda tidak dilaporkan terjadi di Kabupaten Cianjur. Tanaman jagung yang diserang adalah pada bagian titik tumbuh (pucuk tanaman), bunga jagung, daun jagung, dan juga menyerang tongkol jagung. Ditemukan beberapa patogen yang belum diidentifikasi yang berasosiasi dengan S. frugiperda yang dipelihara. Kata kunci: Hama baru, persebaran hama, survei, tanaman jagung., Corn (Zea mays L.) is one of the important commodities after rice as a source of carbohydrate and animal feed. The one of obstacles in the corn cultivation is insect pests. One of the importants insect pests of corn is fall armyworm, Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae). The insect is invasive species on corn plantations in Indonesia since 2019. The aim of this research was to determine distribution of fall armyworm in corn plantation at area of Bogor, Sukabumi, Cianjur, and Tangerang. Survey was conducted in several locations of the corn plantations with different number of location site for each area. The survey includes direct observations of the insect damage and interviews with several corn farmers. Some larvae from the infested plants were collected and it was reared until pupa stage to determine presence of its natural enemies including pathogens or parasitoids that have a potential as natural enemies in the field. The survey result showed that demage of fall armyworm occurred in several corn field locations at Bogor Regency, such as in Cibeber Village with attack area of 14.5% and 17.3% in Cisalada Village; 14.7% of corn field in Cimapak Village, Sukabumi Regency, and 14.3% in Mekarsari Village, Tangerang Regency are reported damaged by this insect. However, there were no evidence that fall armyworm demage occurred at Cianjur Regency during the survey. The part of corn plants that were attacked by fall armyworm were at the growing point (palan shoots), corn flowers, corn leaves, and also attacked the corn cobs. There were unidentified natural enemies associated with the reared insects. Keywords: Corn plantation, new pest, pest attack, pest distribution, survey.
Keyword: Hama baru, Persebaran hama, Survei, Tanaman jagung

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