Judul: Pengaruh cara budidaya bawang daun terhadap serangan pengorok daun Liriomyza spp. dan parasitoidnya
Abstrak: Biological control by natural enemies such as parasitoids is considered as an effective pest control. Intercropping can be done to manipulate the habitat to make suitable for parasitoids. The aim of this research was to study the effect of intercropping of green onion with carrots and spraying of carrot leaf extract on the infestation of leaf miner, Liriomyza spp. (Diptera: Agromyzidae) on green onion and parasitization rate of parasitoids on the pest. The experiment consisted of three treatments and four replications arranged in randomized complete block design (RCBD). The treatments were 1) green onion grown in monoculture system, 2) green onion grown in monoculture system and sprayed with carrot leaf extract, and 3) green onion grown in intercropping system with carrot. Infestation of leaf miner, leaf miner population and parasitization were observed weekly by direct observation and using sticky trap. Two spesies of leafminer, i.e. Liriomyza huidobrensis and L. chinensis were found infesting green onion. Intercropping carrot with green onion and application of carrot leaf extract not affect the infestation of leafminer on green onion
Keyword: Bogor Agricultural University (IPB), parasitoids, Liriomyza spp., intercropping, green onion, carrots

Judul: Lalat penggorok daun Liriomyza spp. (Diptera: Agromyzidae) dan parasitoidnya pada sayuran dataran tinggi dengan perhatian utama pada parasitoid Opius chromatomyiae Belokobylskij & Wharton(Hymenoptera: Braconidae)
Abstrak: Leafminers Liriomyza spp. are major pest on highland vegetables in Indonesia. The objectives of the research were to (1) evaluate leafminer and its parasitoids on higland vegetables, (2) study the intensity of parasitism of O. chromatomyiae in various host plants, (3) study the population dynamic of leafminer and its parasitoid in shallot, (4) evaluate the impact of three insecticides on parasitoid O. chromatomyiae, and (5) evaluate the demographic parameters and functional response of parasitoid O. chromatomyiae. Surveys of leafminer population and its parasitoid were undertaken by collecting 20-40 infested leaves. Leafminer flies and parasitoids emerged were collected and identified. Level of parasitism was calculated based on the number of parasitoids emerged divided by the total number of flies and wasps emerged. The population dynamic of leafminer and its parasitoids were studied on two varieties of green onion, by collecting 20 leaves and counting number of flies catched on yellow traps every week. The impact of insecticides on both leafminers and parasitoids was conducted by applying three different insecticides: abamectin, azadirachtin, and cartaphydrochloride once a week at the recommended dosage. Life table of O. chromatomyiae was studied to determine the population growth potential of the parasitoid, by calculating reproduction rate, intrinsic rate of increase, generation time, and stable age distribution. Functional response was evaluated by exposing O. chromatomyiae on the third instar larvae of L. huidobrensis at eight different host densities (2, 4, 8, 10, 12, 16, 20, and 24) of. Our surveys revealed that Liriomyza huidobrensis, L. sativae, L. chinensis and Chromatomyia horticola were associated with various highland vegetables. Eight parasitoids emerged from leafminer-infested leaves: Hemiptarsenus varicornis, Asecodes deluchii, Neochrysocharis okazakii, N. formosa, Neocrhysocharis sp. Quadrastitchus liriomyzae, O. chromatomyiae and Gronotoma micromorpha. Parasitoid Opius chromatomyiae emerged from 13 different species of vegetables infested by leafminers.. Number of leafminers and parasitoids emerged, and crop damage were significantly different between two green onion varieties tested. Cartap hydrochloride was the most effective insecticide in term for reducing leafminer populations. Even though not as effective as cartap hydrochloride, abamectin and azadirachtin could reduce level of leafminer damage and had lower detrimental effects on natural enemies. Life table studies showed that longevity of females Opius chromatomyiae (9.95 days) shorter than males (11.73 days). Females laid 104.73 eggs with the oviposition rate was 9.31 eggs/days. Reproductive output (R0) was 28.55 with generation time (T) was about 15.96 days and intrinsic rate of increase was 0.21. The stable age ditribution was 37.93% eggs, 24.92% larvae, 20.36% pupae and 16.78% adults. Functional response of O. chromatomyiae is type II (hyperbolic curve) with searching time was 0.0777/hour and handling time was 2.5818/hour.
Keyword: Bawang Daun, Endoparasitoid, West Java

Judul: : Persamaan Tunggal sebagai Representasi Kurva Komposit
Abstrak: A mathematical method is introduced to represent a composite curve based on an extension of analytic geometry. The representation is given either with a single equation or with two equations, in the case of parametric representation. This method permits the representation of composite curves in similar manner to the conventional representation of non-composite curves. Some mathematical tools, including Heaviside unit step function and periodizer function, are used in the establishment of a single equation. In this paper, regular equations of regular and irregular polygon, as well as composite curves of two dimensions, are implemented using a computer algebraic system, Mathematica.
Keyword: