Judul: Diversity and visiting behaviour of insect pollinators in relation to seed set of mustrad (Brassica rapa L. : Brassicaceae)
Abstrak: Insect are known to be pollinators of many species of plants. Cross pollination by insect is esential for maintenance of genetic diversity of plants. Here, we studied the diversity and visiting behaviour of insect pollinators and its effect to sed set of mustard planted in agricultural areas near the Gunung Halimun-Salak National Park, West Java.
Keyword: pollination ecology, social bees, solitary bees, West Java

Judul: Diversity and Abundance of Insect Pollinators in Different Land Use Types in Jambi, Sumatra
Abstrak: Indonesia is one of the tropical countries with high biodiversity. Recently, the biodiversity of plants and animals is declining due to forest converting to settlements, mines, agricultures, and plantations. In Central Sumatra including Jambi, annual deforestation rate reaches 3.2%-5.9%. Converting natural landscapes to agricultural land affects insects biodiversity, including insect pollinators. The research aimed to study diversity and abundance of insect pollinators in different land use types, i.e. oil palm plantation, rubber plantation, and jungle-rubber in Jambi, Sumatra. Observation and collection of insect pollinators were conducted from November until December 2012 at Bejubang, Batanghari regency, Jambi province. Insect observations were conducted in understory plants at three land use types, i.e. oil palm plantation, rubber plantation, and jungle-rubber. Scan sampling method was employed to explore the diversity and abundance of insect pollinators at 08.00-10.00 and 14.00-16.00 in sunny days. This study consist of found 1308 individuals of insect pollinators, belonging to 54 species,7 families, and 3 orders (Hymenoptera, Diptera, and Lepidoptera). Number of species and individual of insect pollinators found in oil palm plantation (43 species, 561 individuals) and rubber plantation (40 species, 650 individuals) were higher than jungle-rubber (7 species, 97 individiuals). Giant honey bee (Apis dorsata) and stingless bee (Trigona sp. (=aff. T. planifrons)) were abundant in oil palm plantation, while stingless bee (T. laeviceps) and small carpenter bee (Ceratina lieftincki) were abundant in rubber plantation. Whereas, hoverfly (Syrphidae sp5) was abundant in the jungle-rubber. The abundance and species richness of insect pollinators in the morning were higher than in the afternoon. Diversity and evenness of insect pollinators in oil palm and rubber plantations were higher than jungle-rubber. The abundant of flower of understory plants in oil palm and rubber plantations indicated insect pollinators forage in those locations. Meanwhile, jungle-rubber and rubber plantations were prefered by insect pollinators for nest building, because there were many large trees, branches, and broken twigs. The insect pollinators community in oil palm plantation and rubber plantation were more similar than in oil palm plantation and jungle-rubber, or in rubber plantation and jungle-rubber.
Keyword: Apidae, Halictidae, insect pollinators, Megachilidae, Syrphidae

Judul: Sintesis dan Pencirian Natrium Titanat (Na2Ti2O4(OH)2) Berbahan Dasar Titanium Dioksida
Abstrak: TiO2 can be utilized as basic material for synthesis of sodium titanate (Na2Ti2O4(OH)2). This research was purposed to synthesize and characterize sodium titanate from TiO2 rutile powder as a basic material. Sodium titanate was synthesized by hydrothermal process at temperature 130 °C by mixing TiO2 rutile powder with 5 M and 10 M NaOH solution, then each was calcinated at temperature 700 °C. The energy dispersive X-ray analysis showed that sodium titanate has been successfully synthesized. This result was also supported by functional group analysis with Fourier transform infrared (FTIR) spectrofotometer showing the existence of Ti-O-Na vibration band at 989.42 cm-1. The formation of sodium titanate was depend on the reaction condition such as temperature, reaction time, and NaOH concentration. Scanning electron microscope image indicated that sodium titanate synthesized at 130 °C in 20 hours reaction time with 10 M NaOH had crystal size of 99.37 nm.
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