Judul: Perilaku serangan dan jumlah populasi kutulilin pinus (Pineus boerneri Annand.) pada Pinus merkusii Jungh. et de Vriese
Abstrak: Pinus merkusii Jungh. et de Vriese adalah satu-satunya spesies pinus yang tumbuh asli di Indonesia, dengan berbagai keunggulan (cepat tumbuh, pionir, dan menghasilkan kayu dan getah), sehingga digunakan sebagai tanaman reboisasi dan penghijauan di berbagai wilayah di Indonesia. Serangan organisme pengganggu tanaman (OPT) dapat menurunkan fungsi hutan. Saat ini yang menjadi masalah pada tegakan pinus adalah adanya serangan kutulilin pinus yang dapat menyebabkan kematian pohon. Tujuan penelitian ini adalah (1) Untuk mempelajari perilaku serangan kutulilin pinus, (2) Untuk mengetahui jumlah individu kutulilin pinus dalam populasi dari 3 kriteria serangan (ringan, sedang, dan berat). Penelitian dilakukan dengan menularkan kutulilin pinus yang berasal dari 5 KPH di Jawa Timur. Kutulilin pinus tersebut ditularkan dari cabang pohon pinus yang terserang dari semua tingkat serangan yang berasal dari masing-masing KPH. Penularan dilakukan pada bibit sehat yang berumur 6 bulan dengan dua metode, yaitu metode penularan dari bagian pohon terserang dan penularan langsung dengan kutu hidup. Penularan dilakukan dengan menempelkan cabang pinus yang terserang kutulilin pinus dari tiap tingkat serangan dan masing-masing KPH sepanjang 5cm, penularan dilakukan pada 3 bibit sehat. Penularan langsung dilakukan dengan mengambil lilin pada cabang pinus yang terserang kutulilin pinus dari tiap tingkat serangan dan masing-masing KPH sebesar 1mm dan diletakkan pada ketiak daun bibit pinus, penularan ini juga dilakukan pada 3 bibit sehat.
Keyword: 

Judul: Identifikasi, siklus hidup dan penyebaran kutulilin pinus pineus boerneri annand (Hemiptera: adelgidae) di hutan tanaman pinus di Pulau Jawa
Abstrak: Pine Woolly Adelgide (PWA), is a newly-found exotic pests, in P. merkusii plantations in Java Island, causing dieback or abnormality of the plants, dried and defoliated branches, and eventually killed the trees. A study was conducted to identified the species of this exotic pest and detrmined its life cycle, as well as geographics distribution. Based on the specific characters of PWA, the insect was identified as Pineus boerneri Annand (Hemiptera; Adelgidae). Abdomen spiracles consisted of four pairs. Wax gland was spread all over the body. The spread was regular at the body, while at the head was irregular. Significantly different measurement of each morphological character observed was found in specimens from different KPH indicating high diversity of the insect despite of its parthenogenetic regeneration. PWA had six stadia of development, which totally lasted for 24,5 ± 1,79 days. The whole cycle was shorter than its original cycle in temperate zone. Shorter life cycle indicates rapid regeneration and multiplication ability that this new pest has a potential for invasiveness. The occurrence of PWA was found concentrated in specific location of host plant area. The pest attacks pine plantation on the high altitude > 900 m above sea level, having temperature between 16-200C, and humidity 80-90%. The intensity of the attack was correlated clearly to temperature and altitude of the host plant location. Percentage of attack ranged from 15-100%. The PWA could attack pine in all ages of development. The fast distribution of attacks and rather narrow range of climatic requirement of the pest posted special call for careful silvicultural consideration for new pine plantation establishment, especially in Java. Recently pine is considered as promising fast growing species for plantation in Java with newly introduced moratorium policy, because pine can give other non-timber forest products, such as gum for terpentine.
Keyword: 

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.
Keyword: