Judul: Identifikasi Keanekaragaman Kapang pada Larva Instar Keenam Ulat Sutera Liar Attacus atlas (Lepidoptera: Saturniidae)
Abstrak: Informasi terkait keberadaan kapang pada Attacus atlas sebagai salah satu ngengat raksasa asli Indonesia ini masih jarang diketahui. Tujuan dari penelitian ini adalah untuk memperoleh data keanekaragaman kapang patogen atau non patogen pada larva instar keenam A. atlas. Kapang diisolasi dari empat bagian larva, yaitu trakea, saluran pencernaan tengah dan belakang, serta hemolimfe. Kapang hasil isolasi tersebut kemudian dikultur pada media potato dextrose agar. Identifikasi kapang secara makroskopis dengan mengamati koloni pada media, sedangkan secara mikroskopis menggunakan metode Riddle dan pewarnaan lactophenol cotton blue. Hasil penelitian menunjukkan bahwa terdapat tiga jenis kapang pada larva instar keenam A. atlas yaitu Aspergillus fumigatus, Aspergillus flavus, dan Fusarium dimerum. Ketiga kapang tersebut bersifat patogen oportunistik sehingga keberadaan kapang dapat berpotensi menimbulkan penyakit pada larva A. atlas…
Keyword: Attacus atlas, Larvae, Mould, Pathogenic mould, Non pathogenic mould, Trachea, Midgut, Hingut, Haemolymph

Judul: Prevalensi Infestasi Parasitoid pada Ulat Sutera Liar Attacus atlas (Lepidoptera: Saturniidae) di Perkebunan Teh Kabupaten Purwakarta
Abstrak: The purpose of this research was to study of prevalence infestation of parasitoids to Attacus atlas (Lepidoptera: Saturniidae), characteristic of the pupae parasitoids discharge, species of parasitoid, and infestation of parasitoid. The results showed the prevalence of parasitoids on A. atlas in the tea plantation Purwakarta Regency was 29.61%. There were three species of parasitoid obtained, i.e. (1) Xanthopimpla gampsura (Hymenoptera: Ichneumonidae) with a prevalence of 21.23%, this parasitoid were make a hole in the anterior pupae (5.39 ± 0.49 mm); (2) Theronia sp. (Hymenoptera: Ichneumonidae) with a prevalence of 6.15%, with hole located anterior (2.75 ± 0.21 mm), lateral (2.67 ± 0.29 mm), and the anterior-lateral holes in one pupae (2.7 ± 0.21 mm), and Parasitoid (3) Exorista sorbillans (Diptera: Tachinidae) with the prevalence of 2.23%. There were 5-8 larva of E. sorbillans / pupa of A. atlas.
Keyword: tea plantation, prevalence, parasitoid, Attacus atlas, Bogor Agricultural University (IPB)

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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