Judul: The Main Pest of Pepper Plants in the Village of Dusun Besar, sub-district of Pulau Maya, Kayong Urata Regency, Kalimantan Barat
Abstrak: Lada (Piper ningrum L.) merupakan salah satu komoditas ekspor yang penting di Indonesia setelah karet, kopi, teh, dan kelapa sawit. Penelitian ini dilakukan untuk mengetahui jenis-jenis hama utama tanaman lada dan kerusakan akibat serangannya di Desa Dusun Besar, Kecamatan Pulau Maya, Kabupaten Kayong Utara, Kalimantan Barat. Penelitian dilakukan pada bulan Maret hingga Juli 2021. Pengamatan hama tanaman lada dilakukan di enam kebun lada di daerah bukit di Desa Dusun Besar, yang masing-masing memiliki 50 tanaman lada dengan pemilik kebun yang berbeda. Hama utama yang menyerang tanaman lada adalah kumbang penggerek batang Lophobaris piperis (Coleoptera: Curculionidae), kepik penghisap bunga Diconocoris hewetti (Hemiptera: Tingidae), dan kepik penghisap buah Dasynus piperis (Hemiptera: Coreidae). Tingkat kerusakan tertinggi disebabkan oleh serangan D. piperis yang mencapai 47,81%. populasi D. piperis banyak ditemukan pada kebun 1 yaitu sebanyak 120 ekor dan terendah pada kebun 4 yaitu sebanyak 55 ekor. Populasi D. hewetti paling banyak ditemukan pada kebun 4 yaitu 19 ekor dan paling rendah pada kebun 6 sebanyak 14 ekor. Rata-rata kelimpahan D. piperis pada bagian bawah 42,5, bagian tengah 37,5, dan bagian atas 12,8. Kelimpahan hama D. piperis pada bagian bawah dan tengah tidak berbeda nyata, tetapi keduanya nyata lebih tinggi dibandingkan dengan pada bagian atas. Rata-rata kelimpahan D. hewetti rendah, dan tidak berbeda nyata antara tajuk bagian bawah, tengah, maupun atas. Kata kunci: hama utama, lada, pengamatan hama, Pepper (Piper ningrum L.) is one of export commodities that important in Indonesia after rubber, coffee, tea, and palm oil. This study was conducted to determine the main types of pepper pests and the damage caused by their attacks in Dusun Besar Village, Pulau Maya district, Kayong Utara Regency, West Kalimantan. Studies were conducted from March to July 2021 in the Dusun Besar. Observations of pepper plant pests were carried out in six pepper platations in the hill area of Dusun Besar Village, each with a total 50 pepper plants with different plantation owners. The main pest that attacks pepper plants were the stem borer Lophobaris piperis (Coleoptera: Curculionidae), the flower-sucking ladybug Diconocoris hewetti (Hemiptera: Tingidae), and the fruit-sucking ladybug Dasynus piperis (Hemiptera: Coreidae). The highest level of damage was caused by D. piperis attack, which reached 47.81%. The population of D. piperis was monthly found in plantation 1, which was 120 individuals and the lowest population was 55 individuals. The highest population of D. hewetti was found in plantation 4 with 19 individuals and the lowest in plantation 6 with 14 individuals. D. piperis averaged 42.5 at the bottom 37.5 and 12.8 at the top. The abundance of D. piperis at the bottom and middle was not significantly different, but both were higher than at the top. The average abundance of D. hewetti was at the bottom at 1.8, the center 2.5, and top at 1.2. The mean abundance of D. hewetti was low, and there was no significant difference between the lower, middle, and upper canopy. Keywords: main pests, pepper, pest observation
Keyword: Main pest, Pepper, Pest observation

Judul: The Main Pest of Pepper (Piper nigrum L.) in East Belitung Regency, Bangka Belitung
Abstrak: Lada (Piper nigrum) merupakan salah satu jenis rempah-rempah yang tak asing bagi masyarakat Indonesia dan banyak ditanam di daerah Indonesia. Lada banyak digunakan oleh masyarakat Indonesia sebagai salah satu komponen bumbu masakan tradisional. Kabupaten Belitung Timur merupakan salah satu sentra tanaman lada di Provinsi Bangka Belitung. Budi daya tanaman lada memiliki faktor pembatas yaitu permasalahan hama dan penyakit yang mengganggu produktivitas tanaman lada. Penelitian ini bertujuan untuk mengetahui jenis hama utama yang menyerang tanaman lada serta mengetahui tingkat serangan hama utama pada tanaman lada di Kabupaten Belitung Timur. Penelitian dilakukan mulai Januari 2020 hingga Maret 2020 di dua kecamatan, masing-masing kecamatan terdiri atas tiga kebun sehingga total kebun yang digunakan sebanyak enam kebun. Tanaman contoh yang digunakan untuk pengamatan sebanyak 10 tanaman contoh per kebun yang ditentukan dengan pola diagonal, sehingga total tanaman contoh sebanyak 60 tanaman. Hama utama yang menyerang tanaman lada yaitu hama pengisap buah (Dasynus piperis), hama pengisap bunga (Diconocoris hewetti), dan hama penggerek batang lada (Lophobaris piperis). Intensitas kerusakan biji per tandan tertinggi ditemukan di Kecamatan Gantung (24.9%), dan terendah di Kecamatan Kelapa Kampit (6.3%). Populasi D. piperis tertinggi terdapat di Kecamatan Kelapa Kampit (17.0 individu/10 tanaman), dan populasi terendah di Kecamatan Gantung (6.3 individu/10 tanaman). Populasi tertinggi D. hewetti sebesar 2.7 individu/10 tanaman terdapat di Kecamatan Kelapa Kampit dan populasi terendah di Kecamatan Gantung sebesar 0.3 individu/10 tanaman. Populasi tertinggi L. piperis sebesar 3.0 individu/10 tanaman terdapat di Kecamatan Gantung dan terendah (0 individu/10 tanaman) di Kecamatan Kelapa Kampit., Pepper (Piper nigrum) is a well-known spice that is widely grown various parts of Indonesia. East Belitung Regency is one of the pepper planting centers in Bangka Belitung Province. Pepper cultivation has limiting factors such as pest and disease problems that reduce the productivity of pepper plants. This study aims to determine the main pests that attack pepper plants and determine the level of damage and population in East Belitung Regency. The study was conducted from January to March 2020. Two districts that have the most pepper plants were selected, and in each district was selected one village with three pepper plantations. In each plantation, ten pepper plants were selected diagonally. Observations were made five times at two weeks intervals. The main pests found were Dasynus piperis (Hemiptera: Coreidae), Diconocoris hewetti (Hemiptera: Tingidae), and Lophobaris piperis (Coleoptera: Curculionidae). The highest level of seed damage per bunch was in Gantung District (24.9%), and the lowest was in Kelapa Sampit (6.3%). The highest population of D. piperis was in Kelapa Kampit District (17.0 individuals/ 10 plants), and the lowest population was in Gantung District (6.3 individuals/ 10 plants). The highest population of D. hewetti was in Kelapa Kampit District (2.7 individuals/10 plants), and the lowest was in Gantung District (0.3 individual/ 10 plants). The highest population of L. piperis was in Gantung District (3.0 individuals/10 plants), and the lowest (0 individual/10 plants) was in Kelapa Kampit District.
Keyword: attack intensity, pest observation, pest population

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
Keyword: