Judul: Mealybugs (Hemiptera: Pseudococcidae) on Chrysanthemum And Their Management Efforts at PT. Natalia Nursery, Bogor West Java
Abstrak: Krisan merupakan tanaman hias bunga potong dan menjadi komoditas ekspor utama florikultura di Indonesia. Usaha dalam budidaya tidak terlepas dari organisme penganggu tanaman, salah satunya kutu putih. Penelitian ini bertujuan mengidentifikasi spesies kutu putih pada krisan, menentukan intensitas serangan dan mengamati gejala kerusakan Phenacoccus solenopsis pada krisan serta upaya pengendaliannya. Identifikasi dilakukan dengan mengoleksi kutu putih yang ada pada tanaman krisan kemudian dibuat preparat mikroskop. Pengamatan intensitas serangan dilakukan pada tiga petak krisan, dan gejala kerusakan dilakukan dengan menginfestasi Ph. solenopsis. Upaya pengendalian dilakukan dengan menguji keefektifan minyak mimba (Azadirachta indica) terhadap Ph. solenopsis, yaitu dengan aplikasi minyak mimba tunggal, sabun sebelum mimba, campuran sabun dan mimba serta kontrol. Metode pengujiannya yaitu larutan disemprot pada tanaman yang diinfestasi kutu putih. Kematian Ph. solenopsis diamati 24, 48, 72, 96 JSP. Hasil identifikasi terdapat empat spesies kutu putih, yaitu: Ferrisia virgata, Ph. solenopsis, Pseudococcus jackbeardsleyi, dan Planacoccus minor yang menjadi hama pada krisan. Spesies F. virgata dan Pl. minor merupakan catatan baru pada tanaman krisan. Intensitas serangan Ph. solenopsis tertinggi yaitu 8.72% dengan populasi 73.5 kutu putih per petak. Kerusakan Ph. solenopsis pada fase vegetatif menyebabkan malformasi di bagian pucuk daun sehingga ukurannya menyusut, keriting, penebalan daun, pembengkokan batang serta pengurangan ukuran secara keseluruhan. Gejala fase generatif menyebabkan daun pelindung seperti terpelintir, bakal bunga tidak berkembang dan pembengkokan tangkai bunga. Aplikasi sabun dilanjut dengan mimba menunjukkan paling efektif terhadap Ph. solenopsis dengan mortalitas sebesar 100% pada 96 JSP., Chrysanthemum is the most exported ornamental cut flower in Indonesia. Its cultivation cannot be separated from pests attacks, especially mealybugs. This study aims to identify mealybugs species on chrysanthemum, to determine the intensity attack level, damage symptom of Phenacoccus solenopsis and its control efforts. Mealybug identification was made by collecting mealybugs and preparing on slide. The intensity and population development of mealybugs were observed on three plots. The damage symptoms caused by mealybugs, a certain number of Ph. solenopsis were infested to the plants and observed. Control efforts were carried out by testing the effectiveness of Neem (Azadirachta indica) against Ph. solenopsis, the plant was treated with single neem oil, combined with soap, applied after soap and control. The method is a solution sprayed on chrysantemum that mealybugs invest in. The death Ph. solenopsis was observed at 24, 48, 72, 96 HAT. The identification result shows that there are four mealybugs species, i.e: Ferrisia virgata, Ph. solenopsis, Planacoccus minor, and Pseudococcus jackbeardsleyi as pest on chrysanthemum. The species of F. virgata and Pl. minor are new mealybugs pests record to chrysanthemum. The highest intensity of Ph. solenopsis is recorded as many as 8.72 % or 73.5 mealybugs per plots. Damage due to mealybugs in the vegetative phase causes malformation in the shoots leaves reported as reduction of leaf size, wavy leaves, curled, thickened, twisted leaves, incurvation of stem, and reduction of overall plant size. Further damage on generative phase showed the incurvation of bud and flower stalk. The most effective treatment against Ph. solenopsis with a mortality of 100% at 96 hour after treatment on soap spraying continued by neem.
Keyword: Azadirachta indica, identification, Malformation, Pseudococcus jackbeardsleyi

Judul: Effectiveness of Cropcoat Insecticides on Phenacoccus solenopsis Chrysanthemum Mealybugs (Hemiptera: Pseudococcidae)
Abstrak: Krisan menjadi komoditas utama florikultura dengan nilai ekspor tertinggi di Indonesia. Salah satu hama penting pada tanaman ini adalah Phenacoccus solenopsis (Hemiptera: Pseudococcidae). Pengendalian menggunakan campuran sabun dan insektisida nabati sering dilakukan oleh petani krisan, masih belum cukup berhasil dalam mengendalikan hama tersebut. Penelitian ini bertujuan menguji keefektifan insektisida Cropcoat dan sabun baik yang diaplikasikan secara berurutan maupun bersamaan terhadap P. solenopsis. Pengujian dilakukan melalui tiga perlakuan yang meliputi aplikasi insektisida Cropcoat tunggal, aplikasi sabun sebelum penyemprotan insektisida Cropcoat, dan aplikasi campuran sabun dengan insektisida Cropcoat. Perlakuan insektisida Cropcoat dilakukan pada tiga taraf konsentrasi yaitu 0,75%, 1%, 1,5% dan kontrol yang diulang 6 kali, kemudian data dianalisis probit untuk menentukan nilai LC50 dan LC95 dari masing-masing perlakuan pada 120 jam setelah pengamatan (JSP). Hasil penelitian menunjukkan bahwa seluruh perlakuan insektisida Cropcoat yang diuji dapat mengakibatkan kematian P. solenopsis pada awal hari pengamatan. Insektisida Cropcoat memiliki sifat antifeedant dengan toksik rendah yang dapat mematikan serangga. Namun, insektisida Cropcoat termasuk golongan yang kurang efektif dalam mengendalikan kutu putih P. solenopsis pada tanaman krisan. Nilai LC50 dan LC95 pengujian insektisida Cropcoat yang diaplikasikan setelah sabun cair berturut-turut sebesar 4,07% dan 7,62%, yang menunjukkan bahwa konsentrasi tersebut merupakan konsentrasi terbaik untuk mematikan nimfa P. solenopsis instar ke-3., Chrysanthemum is one of the most popular floricultural commodities with the highest export value in Indonesia. One of the important pests on this plant is Phenacoccus solenopsis (Hemiptera: Pseudococcidae). The mixture of liquid soap and insecticides is often used by chrysanthemum farmers to control insect pests. This study aimed to verify the efficacy of insecticides Cropcoat and soap, either by single application, sequentially or simultaneously as a control against P. solenopsis. The tests were carried out on three treatments including the application of a single Cropcoat insecticide, application soap before spraying Cropcoat insecticide, and application of soaps mix with Cropcoat insecticide. Cropcoat insecticides were carried out at three concentration levels, 0.75%, 1%, 1.5% and control which each treatment repeated 6 times, then the data were analyzed using probit analysis to determine the LC50 and LC95 values of each treatment at 120 hours after observation. The results showed that all Cropcoat insecticides treatments resulted in insect death on the first day of observation. Cropcoat insecticide has antifeedant properties with low toxicity which can kill insects. However, Cropcoat insecticides were less effective in controlling P. solenopsis on chrysanthemum. The LC50 and LC95 values of insecticide Cropcoat tested which were applied after the liquid soap were 4.07% and 7.62%, respectively, which indicated that these concentrations were the best concentrations to kill the 3 rd instar P. solenopsis nymphs.
Keyword: floriculture, LC values, mortality, soaps

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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