Abstract. Arpiwi NL, Muksin IK, Kartini NL. 2020. Essential oil from Cymbopogon nardus and repellant activity against Aedes aegypti. Biodiversitas 21: 3873-3878. Cymbopogon nardus (L.) Rendle is an aromatic grass from the Poaceae family that produces essential oil mainly in the leaves. The essential oil from C. nardus is known as citronella oil has repellent activity. This research aimed to quantify the oil content of C. nardus leaves, to analyze the essential oil quality, to analyze the repellent activity of lotion with different concentrations of citronella oil against Aedes aegypti, and to examine the quality of formulated lotions. The oil was extracted from leaves using steam distillation, and the quality was examined according to the Indonesian National Standard. The citronella oil was formulated into a lotion with five concentrations (0, 2, 3, 4, 5% w/w). Repellent activity of the lotions against Ae. aegypti was tested using screened cage test method under laboratory conditions. Lotion quality was analyzed for pH, viscosity, homogeneity, and sensorial assessments. The result showed that the oil yield of C. nardus leaves was 0.9% w/w. The color of the oil was pale yellow, specific weight was 0.8819, the refraction index was 1.464, total geraniol was 72.71%, citronellal content was 49.14%, and solubility in 80% alcohol 1:2 was clear. The repellent activity of lotions with citronella oil was concentration-dependent, where a concentration of 5% gave the highest protection. The quality of formulated lotions met the standard and the lotions were nonirritant.
Sunda Strait has high potential of pelagic fish resources, one of which is spotted sardinella (Amblygaster sirm). High market demand of spotted sardinella leads to its high exploitation. Management of sustainable used of this species need various biological information of the target species.The aims of this research wereto analyze of therecruitment pattern, mortality, and exploitation rate of spotted sardinella. Sampling was conducted in April to August 2015 from the catchment landed at Labuan Coastal Fishing Port, Banten. Fish samples taken during the study consisted of 527 males and 245 females. The results showed thatpeak recruitment season for spotted sardinella occurs in Maret (11.64%) and July (13.67%).The natural mortality (M), fishing mortality (F), total mortality (Z) for male were 0,33; 5,30; 5,63 year-1 respectively, and for female were 0,51; 7,75;8,27 year-1 respectively. Exploitation rate (E) for male was 0,94 year-1 and for female was 0,93 year-1.Keywords : exploitation, growth, mortality, spotted sardinella, Sunda Strait
Earthworms are one of the soil macroorganisms that have a very important role in maintaining soil quality in a sustainable manner. Lumbricus rubellus is one of 1800 types of earthworms that live on the surface of the soil which has the ability to degrade very high organic matter. The quality of vermicompost fertilizer is strongly influenced by the types of media because decaying speed is determined by the C / N ratio. This study aims to determine the type of media that is best used to improve the quality of vermicompost fertilizer. Experiment was used completely randomized blok design in factorial pattern. he first factor is the population of worms consisting of 4 levels (Control, 20 Tails, 40 Tails, and 60 Tails). The second factor is media worms consisting of 4 levels (slurry cattle + 25% straw, slurry pigs + 25% straw, slurry cattle + 25% straw + 25% vegetables waste, slurry pigs + 25% straw + 25% vegetables waste) with three replication so that there are 48 test units. The results showed that the interaction of treatments had a very significant effect on: decay speed, C-organic, population of earthworms, earthworm eggs, total microorganism population, and pH of vermicompost, except P-available and N-total. It can be concluded that the best vermicompost quality in the study was slurry cow + 25% rice straw + vegetable waste and 60 earthworms. Keywords: cow slurry, rice straw, vegetable waste, earthworm, vermicompost
Utilization of ex-sand pit lakes for aquaculture is difficult due to low water quality and high concentrations of iron (Fe). Phytoremediation using aquatic plants has been proven to be effective in reducing Fe in waters. This study aims to determine the growth, feed conversion efficiency and survival rate of tilapia (Oreochromis niloticus) cultured with ex-sand mining water media with phytoremediation treatment. Phytoremediation treatment was carried out by Eichhornnia crassipes, Azolla pinnata, and Salvinia molesta. Fish culture experiments were carried out in plastic tarpaulin tanks for 40 days, with ad satiation feeding, three times a day using the commercial feed. The results showed that phytoremediation with aquatic plants had succeeded in reducing Fe to a level suitable for fish culture. Fish culture experiments showed an absolute length growth rate of 0.09-0.18 cm/day and an absolute weight growth rate of 0.11-0.16 g/day. The feed conversion ratio was 1.18-1.40 and the survival rate was 98.04-99.08%. The survival rate of tilapia is high, the feed conversion ratio is medium and growth is low. The high environmental temperature and the decrease in water quality due to the absence of water changes and aeration are suspected of causing the low growth of fish. Therefore, further research with water change and aeration experiments and the use of other species of fish is needed to follow up the results of this study.
Macrozoobenthos is one of the organisms that can be used as biological indicators because it tends to live in an area and has sensitivity to environmental changes. The Hurun River had many community activities. Based on this, it was necessary to analyze the diversity of macrozoobenthos which will be compared with the physical and chemical parameters of water in order to find out the indicators that affect the abundance of macrozoobenthos in the river. The purpose of this research was to determine the macrozoobenthic community structure which found in the Hurun River based on diversity, uniformity and dominance indices, to build multiple linear regression models, and to determine the bioindicators of pollution in the Hurun River. The factors that influence the abundance of macrozoobenthos are temperature, depth, brightness, DO, TOM, and salinity. The types of macrozoobenthos obtained were 87 species with the highest abundance of macrozoobenthic animals of 70,666.56 ind/m3 while the lowest abundance of macrozoobenthic animals was 13,000.96 ind/m3. Based on data analysis, the macrozoobenthic diversity index was included in the medium category, the level of macrozoobenthic uniformity was included in the high, medium, and low categories, and the dominance level which was included in the medium and low categories. Multiple regression models with a confidence level of 5% get R2 results of 0.86. The level of pollution that occured in the Hurun River based on bioindicators with the ABC curve shows moderately polluted.
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