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Investigating beneficial chemical compounds of plant extracts is one of the ways to prevent biodiversity loss. This study evaluated the antimicrobial activity of indigenous plant extracts from Toba , North Sumatra, and Mt. Merapi National Park regions against Escherichia coli , Bacillus subtilis , Salmone l la typ h i , Staphylococcus aureus , Candida albicans , and Candida tropicalis by calculating the zone of microbial growth inhibition. Among the plant extracts, T 5 that identified as Toona sinensis showed the highest microbial inhibit ion to the growth of C. albicans , B. subtilis , S. typhi, and E. coli with the diameter growth of approximately 2.00, 1.80, 1.33, and 1.33 cm, respectively. Based on those results, T. sinensis was then subsequently fractionated using n-hexane, ethyl acetate, and methanol , respectively. The resulted fractions also were evaluated for antimicrobial bioassay. A ll fractions have shown activity in inhibiting the growth of the microbes at 1% concentration. However, each fraction show ed growth inhibition against certain microbe s . The n-hexane fraction show ed the greatest inhibitory activity for E. coli and S. typhi ; ethyl acetate fraction for B. subtilis and C. albicans ; and methanol fraction for E. coli and S. typhi . The results revealed that T. sinensis plant extract has great potential as an antimicrobial agent . Further investigation is needed to observe the mode of anti microbial action of fractionated crude extracts of T . Sinensis . The exploring potency of Indonesian biodiversity opened up a new way for the utilization of plants for economic development and conservation . Keywords: antimicrobial plants, indigenous knowledge, Toba-North Sumatra, Mt. Merapi

Entomopathogenic fungi have the potential to infect most arthropods including termites which are economically important major insects pest of wood, wood products and building structures. However, the application of this fungus in the field has not shown satisfactory results yet, one of which is constrained in mass production of conidia. The purpose of this study was to evaluate 16 types of biodegradable products and waste as substrates for mass production of conidia using solid state fermentation method and two types of inoculum namely solid and liquid inoculum. Toxicity tests were carried out on subterranean termites ( Coptotermes sp.) based on JIS K 1571, 2010. The parameters observed were the number and dry weight of the conidia produced, conidial viability, nutrient content of the substrate, and percentage of termite mortality. The results showed that rice, sorghum and corn were the best media for the growth of entomopathogenic fungi based on the number of conidia and dry weight of the conidia produced. Metarhizium sp. T4.B23 produced the highest number of conidia, 1.12 x 10 11 conidia/100 g substrate and yielded 180.9 ± 0.623 g dry conidia/kg of rice; followed by Metarhizium sp. B2.2 grown on sorghum that resulted in 1.11 x 10 10 conidia/100 g substrates and 8 ± 0.570 g /kg sorghum; and B. bassiana produced 8.3 x 10 9 conidia/100 g substrate and 31.24 ± 0.407 gr/ kg sorghum. Metarhizium sp. B2.2 showed the highest toxicity to termites with 100% mortality was observed within the second day of testing. Therefore the conidia of Metahizium sp. B2.2 is potential to be developed as a biopesticide using rice or sorghum substrate as a carrier.

The Indo-Malayan drywood termite, Cryptotermes cynocephalus (Light) (Kalotermitidae), is considered one of the most invasive drywood termites in the Southeast Asian region. Once infesting a timber, the colony of a drywood termite is very difficult to be controlled. Thus, the best way to mitigate a new infestation of a drywood termite is by applying chemical protection on wood. In recent years, particular attention has been given by researchers to develop and use organic termiticides, such as essential oils extracted from plants as active ingredients. The objective of the present study is to evaluate the repellency performance of several economically important essential oils from Indonesia, such as Clove (Eugenia caryophyllata), Cubeb Pepper (Piper cubeba L), and Lemon Grass (Cymbopogon winterianus Jowitt) against a drywood termite, C. cynocephalus. The test was performed by subjecting various concentrations of essential oil toward C. cynocephalus in the force-feeding test method. Sample weight-loss was evaluated after two weeks test. The results suggested that Clove oil has the highest repellence performance against C. cynocephalus, followed by Lemon Grass and Cubeb Pepper oils. The Termite mortality rate was also recorded to understand the toxicity performance of those essential oils.

Cymbopogon nardus, Syzygium aromaticum, and Citrus sinensis have been well known to possess insecticidal activity. Here, we investigated the repellent activity of individual of three essential oils (C. nardus, S. aromaticum, C. sinensis) and a combination of essential oils (C. nardus + C. sinensis, C. nardus + S. aromaticum, and C. sinensis + S. aromaticum) against a dengue vector, Aedes aegypti and a filarial vector, Culex quinquefasciatus. The essential oils (1 mg) were smeared evenly on the surface of the left arm (three volunteers) and then subjected to 25 females of A. aegypti and C. quinquefasciatus in the cage. The number of landed mosquitos was observed every hour for 7 hours to determine the protection index (PI). The result showed that individuals of three essential oils and a combination of essential oils generated > 90% of PI until 7 hours of application for both mosquitos species tested. Overall, the data demonstrated that individual of three essential oils, i.e., C. nardus, S. aromaticum, C. sinensis, and various combinations of essential oils (C. nardus + C. sinensis; C. nardus + S. aromaticum; C. sinensis + S. aromaticum) are promising as repellent agents against A. aegypti and C. quinquefasciatus.

Mosquitoes are known for their bites which caused discomfort and its role as vector for various dangerous diseases that has been the bane of humanity since antiquity. One of them is Culex quinquefasciatus which facilitates the spread of arbovirus and nematodes that caused debilitating impact for human life. To eliminate mosquito, the study for evaluating plant-based mosquito larvicidal extract of Cerbera odollam extract against C. quinquefasciatus was conducted. Twenty-five second instar of C. quinquefasciatus were subjected to the crude and fractionated extracts of C. odollam, and the larval mortality was observed at 24, and 48 h of exposure. The results showed that the crude extracts of leaves, rinds, and stem bark exhibited low larvicidal activities. Interestingly, crude extract of the seed kernel exhibited high larvicidal activity. We found that the fractionated extract derived from the seed kernel extract using ethyl acetate and n-hexane exhibited high larvicidal activities, suggesting that C. odollam extract could be promoted as a material for larval control.

The wood-rot fungus is one of the most destructive organisms for wood, wood products and building structures besides termites and beetles. Until today, wood-root fungi are still difficult to control, so it is necessary to search for new natural ingredients to be developed as wood preservatives. The purpose of this study was to screen some plant extracts from the area surrounding Lake Toba as anti-wood-rot fungi. This study evaluated antifungal properties of 6 different plant extracts dissolved in methanol against 9 species of wood-rot fungi. The activity was determined using the method of Mohareb [1] by growing the fungi on PDA supplemented with the plant extracts. Parameters observed included diameter of fungal growth and inhibition percentage of fungal growth by plant extracts. Extracts of Tithonia diversifolia, Chromolaena odorata, Saurauia bracteosa dan Azadirachta indica displayed extraordinary activity in inhibiting the growth of wood rot, up to 100%, therefore these plant extracts have the potential to be further investigated as wood rot control agent.

The purpose of this study was to apply microbial suspension of which formulated as bio-insecticide to observe its effectiveness in controlling insect pest on chili plants, Capsicum annum L. The efficacy of bio-insecticide was evaluated based on potential entomopathogenic microorganisms used in the microbial suspension. The bio-insecticide consisted of entomopathogenic fungal and bacterial suspensions. The experiment was carried out in chili cultivation area in Situ Gede, Bogor. The application used spray method with multiple various doses. The observation showed that the plant treated with spore suspensions of entomopathogenic fungi Metarhizium sp. T4B23, B2-2, and cell suspensions of entomopathogenic bacteria Bt + SP4, were able to resist against insect pests, such as whitefly, grasshopper, and armyworm. In addition, the treated plant had more vigorous growth and yield than the control treatment.

Isolation of phytopahtogen and antagonistic fungi is important in the efforts for managing phytopathogen infestation in cacao plantations. It is related to developing studies to evaluate the association between the two types of organism in the context of establishing integrated pest management to manage widespread pest and disease in cacao crop. This research objective is to study and isolate phytopathogens and antagonistic fungi on cacao. Fungal isolation was conducted from black diseased-cacao pod and soil samples through surface sterilization and serial dilution, respectively. After several culture purification, four fungal isolates were identified through macroscopic colonies and microscope observation. Those fungal isolates are Curvularia, Fusarium, Aspergillus and Trichoderma. Further research is necessary to test their antagonistic and or synergistic associations in laboratory and field scales.

Termite’s biodiversity is known to be strongly affected by disturbance, particularly in an urban area. The present study evaluated termite biodiversity and distribution in Batam Botanical Garden, an urban conservation area in Batam Island. In the surveyed area, termites could play a major beneficial role through the promotion of essential ecological processes in ecosystems, such as soil modification and rehabilitation; as well as their well-established role as pests for vegetation. Therefore, biodiversity evaluation of termite is very important to identify economically and ecologically important species. Termite survey had been conducted by a 100 × 2 m belt-transect. Transect area was divided into 20 sections (5 × 2 m), in which each section was surveyed for 30 minutes by two trained people. In total, 106 specimens (15 termite genera) were collected from three sampling sites: Plantation, Mangrove forest, and Forest.

Toba, North Sumatera is famous not only for its tourism destination but also for biodiversity. The aim of this research is to explore the potency of the local plant from Toba as bioinsecticide. Six local plant samples, which consists of genus Compositae, Meliaceae, Staphyleaceae, and Actinidiaceae, were obtained from the Toba region,. The macerated extracts were tested their insecticidal activity against Coptotermes gestroi and Spodoptera litura. Bioassay results showed that leaves extract of Ingul (Toona sinensis) at a concentration of 10% (w/v) had the highest mortality effect against Coptotermes gestroi on the tenth day of observation. Whereas, leaves extracts of Pirdot (Saurauia bracteosa), Ingul (Toona sinensis), and Haurese (Azadirachta indica) at the concentration of 1% (w/v) showed the best insecticidal effect with 80% mortality percentage respectively against Spodoptera litura in 4 hours of observation.