Judul: Serangga Hama Menusuk-mengisap pada Tanaman Terung dan Populasi Kutu Putih di Tiga Tanaman Solanaceae
Abstrak: Terung (Solanum melongena L.) merupakan salah satu komoditas penghasil buah yang berasal dari Famili Solanaceae dan banyak digemari masyarakat. Penurunan produktivitas tanaman terung dapat dipengaruhi oleh tingkat kepadatan organisme pengganggu tanaman yang menyerang tanaman budidaya. Serangan hama merupakan salah satu faktor yang dapat mengakibatkan penurunan produksi secara kualitatif dan kuantitatif. Saat ini kutu putih terung ditemukan menyerang tanaman terung di Kecamatan Sukamakmur dan Kecamatan Simpang tiga, Aceh Besar. Oleh karena itu, penelitian ini dilakukan untuk mengetahui kepadatan populasi dan mengidentifikasi hama menusuk-mengisap dan mengetahui preferensi kutu putih pada 3 tanaman uji. Penelitian ini dilakukan di dua lokasi, yaitu Desa Lampisang dan Desa Blang Preh. Pengamatan hama dan perhitungan populasi hama menusuk mengisap dilakukan pada 10 tanaman sampel secara diagonal. Uji preferensi kutu putih dilakukan pada 3 tanaman Solanaceae, yatu terung, tomat dan cabai dilakukan untuk melihat kemampuan bertahan hidup dan kepadatan populasi. Hasil penelitian menunjukkan hama yang menyerang pertanaman terung di lapangan diantaranya adalah Ferrisia sp 1., Coccidohystrix sp 1., Aphis sp 1., Bemisia sp 1., dan Empoasca sp 1. Populasi hama di lahan Desa Lampisang lebih tinggi dibandingkan hama di lahan Desa Blang Preh. Preferensi kutu putih Coccidohystrix sp 1. tertinggi terjadi pada pengamatan 30 HSI (hari setelah infestasi) pada tanaman uji terung dan tomat. Tanaman tomat berpotensi menjadi inang alternatif selain tanaman terung, karena kutu putih Coccidohystrix sp 1. juga menyukai tanaman tomat. Selain itu, kutu putih Coccidohystrix sp 1. juga ditemukan menyerang gulma famili Asteraceae., Eggplant (Solanum melongena L.) is one of the fruit-producing commodities from the Solanaceae family and is very popular with the public. The decrease in eggplant productivity can be influenced by the density of plant pests that attack cultivated plants. Pest is one of the factors that can lead to a decrease in production qualitatively and quantitatively. Currently, eggplant mealybugs have been found attacking eggplant plants in Sukamakmur and Simpang Tiga sub districts, Aceh Besar. Therefore, this study was conducted to determine the population density and identify sap-sucking pests and to determine the preference of mealybugs on the 3 test plants. This research was conducted in two locations, namely Lampisang Village and Blang Preh Village. Observations of pests and population calculations of sap-sucking pests were carried out on 10 plants, which were sampled diagonally. The mealybug preference test was carried out on 3 Solanaceae plants, namely eggplant, tomato and chili to observe the survival ability and population density. The results showed that the pests that attacked eggplant plantations in the field were Ferrisia sp 1., Coccidohystrix sp 1., Aphis sp 1., Bemisia sp 1., and Empoasca sp 1. The population of pests in Lampisang Village was higher than those in Blang Preh Village. Based on the 30-DAI observations (days after infestation) of mealybug’s feeding preference, tomato plant was also a potential host plant other than eggplant. In addition, the mealybug Coccidohystrix sp 1. was also found attacking weeds of the Asteraceae family.
Keyword: Kutu putih Coccidohystrix sp 1, serangga pengisap, populasi, preferensi

Judul: Keanekaragaman Kutu Putih (Hemiptera:  Pseudococcidae) dan Cendawan Entomophthorales pada Berbagai Tanaman di  Kabupaten Bogor
Abstrak: Hama dan penyakit tanaman merupakan salah satu faktor penyebab menurunnya produktivitas tanaman budi daya. Hama kutu putih merupakan serangga yang umum ditemukan pada tanaman budi daya. Serangga ini bersifat polifag yang memiliki inang dari berbagai famili tanaman. Kutu putih umumnya ditemukan secara berkelompok pada bagian tanaman yang terserang dan menghisap cairan tanaman. Cendawan Entomophthorales merupakan salah satu musuh alami kutu putih. Gejala lanjut dari kutu putih yang terinfeksi cendawan Entomophthorales yaitu tubuh kutu putih berwarna abu-abu atau hitam. Tujuan dari penelitian ini adalah untuk mengetahui keanekaragaman kutu putih dan asosiasinya dengan cendawan Entomophthorales pada berbagai tanaman inang. Kutu putih dikoleksi dari tanaman alpukat, biriba, bisbul, jambu kristal, jeruk nipis, nanas, pakcoy, pisang, dan singkong. Kutu putih yang ditemukan sebanyak tujuh spesies, yaitu Dysmicoccus brevipes, Dysmicoccus lepelleyi, Exallomochlus hispidus, Ferrisia virgata, Nipaecoccus sp., Paracoccus marginatus, dan Rastrococcus marginatus. Hanya satu spesies kutu putih yang terinfeksi cendawan Entomophthorales yaitu P. marginatus yang ditemukan pada tanaman pepaya dan singkong. Fase cendawan pada kedua tanaman inang yang ditemukan pada P. marginatus adalah hyphal bodies., Plant pests and diseases are one factor cause decrease in the productivity of cultivated plants. The mealybug pests are common insect pest found on cultivated plants. These insects are polyphagous and have hosts from various plant groups. Mealybugs are generally found in clusters on infested plant parts and suck plant fluids. The entomophthoralean fungus is one of the natural enemies of mealybugs. Mealybugs with gray or black bodies are signs of advanced Entomophthoralean fungal infection. The objective of these research is to determine diversity of mealybugs and it is associated with their entomophthoralean fungus on various cultivated plants. Mealybugs were collected from avocado, biriba, bisbul, crystal guava, lime, pineapple, pakcoy, banana and cassava plants. There are seven species of Mealybugs found during this research: Dysmicoccus brevipes, D. lepelleyi, Exallomochlus hispidus, Ferrisia virgata, Nipaecoccus sp., Paracoccus marginatus, and Rastrococcus spinosus. Only one of mealybugs infected by entomophthoralean fungus is P. marginatus on papaya and cassava plants. Fungal phase on both hosts which found on to be infective P. marginatus is the hyphal body.
Keyword: hyphal bodies, P. marginatus, polyphages

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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