Judul: The Effect of Three Active Ingredients of Synthetic Insecticides on The Activity of Tetragonula laeviceps Smith (Apidae: Meliponini) in Tomato
Abstrak: Lebah merupakan agens penyerbuk yang berperan penting dalam meningkatkan produktivitas tanaman. Tetragonula laeviceps (Apidae: Meliponini) merupakan lebah yang umum ditemukan di Indonesia berpotensi sebagai agens penyerbuk tanaman. Aplikasi insektisida sintetik diduga menjadi salah satu penyebab penurunan populasi koloni lebah. Penelitian ini bertujuan untuk mengetahui pengaruh aplikasi insektisida berbahan aktif imidakloprid, abamektin, dan profenofos terhadap aktivitas kunjungan lebah T. laeviceps pada pertanaman tomat. Penelitian dilakukan pada skala semilapangan di dalam rumah plastik (panjang 6,5 m, lebar 6,5 m, dan tinggi 2,5 m). Tahapan uji semilapangan meliputi penyiapan lahan dan penanaman, peletakan koloni lebah, aplikasi insektisida berbahan aktif imidakloprid, abamektin, dan profenofos dengan konsentrasi formulasi berturut-turut 4 g/l, 1 ml/l, dan 2 ml/l. Peubah pengamatan meliputi aktivitas lebah, pengujian tingkat kulitas dan kuantitas buah tomat, serta penentuan estimasi nilai ekonomi penyerbukan. Berdasarkan hasil pengamatan insektisida berpengaruh terhadap aktivitas kunjungan lebah T. laeviceps pada pertanaman tomat. Perlakuan insektisida berbahan aktif imidakloprid dan profenofos menunjukkan adanya pengaruh pada aktivitas kunjungan lebah setelah penyemprotan insektisida. Lama kunjungan lebah T. laeviceps pada bunga pada perlakuan imidakloprid, abamektin, profenofos dan kontrol secara berurutan, yaitu 10,88; 66,05; 12,86; dan 86,29 detik, sedangkan lama kunjungan lebah ke tanaman pada imidakloprid, abamektin, profenofos dan kontrol secara berurutan, yaitu 10,00; 55,67; 12,91; dan 77,95 detik. Perilaku lebah berkunjung ke bunga ternyata memberikan pengaruh tidak langsung terhadap bobot, diameter, panjang buah, dan fruit set. Akibat adanya aplikasi insektisida di lapangan, lebah T. laeviceps berpengaruh terhadap aktivitas kunjungan dan pencarian makan ke tanaman, sehingga aplikasi insektisida perlu memerhatikan keberadaan serangga penyerbuk seperti lebah T. laeviceps., Bees are pollinating agents that play an essential role in increasing plant productivity. Tetragonula laeviceps (Apidae: Meliponini) is a bee commonly found in Indonesia which has potential as a plant pollinating agent. The application of synthetic insecticides is thought to be one of the causes in declining the bee colony populations. This study aimed to determine the effect of the application of three insecticide active ingredients; imidacloprid, abamectin, and profenofos on the visiting activity of T. laeviceps bees and the productivity of tomato plants. The research was conducted on a semi-field scale in a plastic house (6.5 m in length, 6.5 m in width, and 2.5 m in height). The semi-field test stages included land preparation and planting, placing bee colonies, and application of insecticides with active ingredients of imidacloprid, abamectin, and profenofos with formulation concentrations of 4 g/l, 1 ml/l, and 2 ml/l, respectively. Observational variables include bee visits, evaluation of the level of quality and quantity of tomatoes, and determining the estimation of the economic value of pollination. Based on the results of observations, insecticides affected the T. laeviceps visit activities to flowers and tomato plants. Imidacloprid and profenofos treatments gave the effect on the visiting activity of bees on plants and flowers after spraying insecticides. The durations of the visit of T. laeviceps bees to flowers and tomato plants on imidacloprid, abamectin, profenofos treatments, and control were 10,88; 66,05; 12,86; and 86,29 seconds and 10,00; 55,67; 12,91; and 77,95 seconds, respectively. The behavior of bees visiting flowers has an indirect effect on weight, diameter, fruit length, as
Keyword: abamectin, bee visit, imidacliprid, profenofos

Judul: Pengaruh aplikasi tiga jenis insektisida terhadap aktivitas terbang lebah Tetragonula laeviceps Smith (Apidae: Meliponini)
Abstrak: Lebah memiliki peran besar dalam membantu proses penyerbukan komoditas pertanian dan memiliki peran penting bagi keseimbangan ekosistem. Penggunaan insektisida secara intensif pada lahan pertanian diduga menjadi salah satu penyebab terjadinya colony collapse disorder (CCD) atau fenomena berkurangnya jumlah koloni lebah di dunia. Penelitian ini bertujuan untuk mengetahui pengaruh insektisida imidakloprid, profenofos, dan abamektin terhadap aktivitas terbang Tetragonula laeviceps Smith di lapangan. Penelitian dilakukan di dalam screen house (panjang 6,5 m, lebar 6,5 m, dan tinggi 2,5 m). Metode penelitian meliputi penyiapan lahan dan penanaman, pemeliharaan tanaman, peletakan koloni lebah, aplikasi insektisida berbahan aktif imidakloprid 200 g/l, profenofos 500 g/l, dan abamektin 18 g/l dengan konsentrasi formulasi berturut-turut 4 g/l, 1 ml/l, dan 2 ml/l serta pengamatan aktivitas lebah T. laeviceps pada tanaman tomat. Hasil penelitian menunjukkan bahwa perlakuan insektisida imidakloprid dan profenofos berpengaruh sangat nyata terhadap aktivitas keluar dan masuk sarang lebah pada tanaman dibandingkan dengan perlakuan insektisida abamektin dan kontrol. Selain itu, ketiga insektisida tersebut juga mempengaruhi lama kunjungan bunga dan tanaman yaitu berturut-turut 22,17; 40,32; 16, 92; 22,84; 29,47; 45,96; 29,87; dan 64,74 detik (perlakuan imidakloprid, profenofos, abamektin, dan kontrol). Aplikasi insektisida mempengaruhi aktivitas terbang dan dapat menyebabkan kematian pada lebah. Hal ini akan mempengaruhi proses penyerbukan pada tanaman dan menurunkan produktivitas pertanian., Bees have a big role in helping pollinate agricultural commodities and have an important role in the balance of the ecosystem. The intensive use of insecticides on agricultural land is thought to be one of the causes of colony collapse disorder (CCD) or the massive reduction in the number of bee colonies worldwide. This study aimed to determine the effect of imidacloprid, profenofos, and abamectin insecticides on the flying activity of Tetragonula laeviceps Smith in the field. The research was carried out in a screen house (6,5 m in length, 6,5 m in width, and 2,5 m in height). Research methods include land preparation and planting, plant maintenance, laying bee colonies, application of insecticides containing the active ingredients imidacloprid 200 g/l, profenofos 500 g/l, and abamectin 18 g/l, with formulation concentrations of 4 g/l, 1 ml/l, and 2 ml/l, respectively as well as observing the activity of T. laeviceps bees on tomato plants. The results showed that the imidacloprid and profenofos treatments significantly affected the activity of entering and leaving beehives on tomato plants compared to abamectin and control insecticide treatments. Apart from that, the three insecticides also affect the length of visits to flowers and plants visits, namely 22,17; 40,32; 16,92; 22,84; 29,47; 45,96; 29,87; and 64,74 seconds (imidacloprid, profenofos, abamectin, and control treatment). Insecticide application affects the flying activity and can cause death in bees. This will affect the pollination process in plants and reduce agricultural productivity.
Keyword: abamectin, apis, colony collapse disorder, imidacloprid, profenofos

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.
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