BIOTROPIA - The Southeast Asian Journal of Tropical Biology
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POTENTIAL ROLE OF WILD CRUCIFERS IN THE PRESERVATION OF DIADEGMA EUCEROPHAGA HORSTMAN (HYMENOPTERA: ICHNEUMONIDAE), A PARASITOID OF THE DIAMONDBACK MOTH, PLUTELLA XYLOSTELLA LINNAEUS (LEPIDOPTERA: PLUTELLIDAE)
Get PDFLaboratory and field experiments were conducted to evaluate the potential role of two species of wild crucifers in the preservation of Diadegma eucerophaga Horstman, a parasitoid of the diamondback moth, Plutella xylostella Linnaeus. In the laboratory, D. eucerophaga developed quite well on P. xylostella larvae fed on leaves of two species of wild cruciferous plants, Nasturtium heterophyllum BL. and Cardamine hirsuta L. These wild crucifers may serve as food and oviposition sites for P. xylostella. In the field, N. heterophyllum and C. hirsuta planted adjacent to insecticide-treated cabbage plots provided refuge for D. eucerophaga parasitoids
POLLINATION EFFECTIVENESS OF APIS CERANA FABRICUS AND APIS MELLIFERA LINNAEUS (HYMENOPTERA: APIDAE) IN JATROPHA CURCAS L. (EUPHORBIACEAE)
Get PDFPollinators are well known to provide key ecosystem. Animal pollinators are thought to contribute between 15 and 30% of global food production and bees are recognized to be the most important taxon. The pollination effectiveness of two species of bees, Apis cerana and A. mellifera (Hymenoptera: Apidae) in Jatropha curcas (Euphorbiaceae) was studied. Three cages, made of insect screen were set up. Each cage contains three individual plants. One colony of A. mellifera and A. cerana were placed in the first and second cage, while the third cage was used for control plants. Bee colonies were placed during one month in the first and second cages.  Fruit set of plants pollinated by A. mellifera, A. cerana, control plants, and open plants were counted and compared. Pollination by honeybees increased the number of fruits per plant and fruits per raceme of J. curcas. Based on measuring of fruit produced by plants, pollination effectiveness of A. mellifera was higher than A. carana.
Key words: Pollination, effectiveness, Apis cerana, A. mellifera, seed set, Jatropha curcas
ESTIMATION OF SEAGRASS COVERAGE BY DEPTH INVARIANT INDICES ON QUICKBIRD IMAGERY
Get PDFManagement of seagrass ecosystem requires availability of information on the actual condition of seagrass coverage. Remote sensing technology for seagrass mapping has been used to detect the presence of seagrass coverage,  but so far no information on the condition of seagrass could be obtained. Therefore, a research is required using remote sensing imagery to obtain information on the condition of seagrass coverage. The aim of this research is to formulate mathematical relationship between seagrass coverage and depth invariant indices on Quickbird imagery. Transformation was done on multispectral bands which could detect sea floor objects that are in the region of blue, green and red bands. The study areas covered are the seas around Barranglompo Island and Barrangcaddi Island, westward of Makassar city, Indonesia. Various seagrass coverages were detected within the region under study. Mathematical relationship between seagrass coverage and depth invariant indices was obtained by multiple linear regression method. Percentage of seagrass coverage (C) was obtained by transformation of depth invariant indices (Xij) on Quickbird imagery, with transformation equation as follows: C = 19.934 – 63.347 X12 + 23.239 X23. A good accuracy of 75% for the seagrass coverage was obtained by transformation of depth invariant indices (Xij) on Quickbird imagery.  Keywords: seagrass coverage, depth invariant inde
A STUDY ON WEED CONTROL IN SOYBEAN
Get PDFTwo field experiments on weed control in soybeans were carried out at BIOTROP, Bogor, Indonesia from February to June, 1989. The critical period for weed control was found to be between 20 - 40 days after planting of soybean (c. v. Wilis) grown at a planting distance of 40 x 10 cm. It did not coincide with the fastest growth in terms of trifoliate leaf number. Further studies were suggested to understand the physiological growth of soybean related to weed control. Pendimethalin at 660- 1320 g a.e./ha applied one day after sowing did not cause any phytotoxic effect to soybean and had good weed control performance
A NOVEL INTEGRON IN THE GENOME OF ESCHERICHIA COLI ISOLATED FROM INDONESIAN MONITOR LIZARD (VARANUS SPP).
Get PDFThe genotype of antibiotic resistance in natural isolates of Escherichia coli was determined through integron detection and characterization of the associated antibiotic resistance. E. coli SG2 isolated from Varanus salvator of Java demonstrated resistance to spectinomycin (50ng/ml) and streptomycin (SOng/ml). Integron detection indicated that eight isolates out of nine E. coli isolates possessed a conserved segment of the integron. Amplification of the inserted cassette of the integron in this SG2 isolate yielded a 1-kb DNA fragment. Sequence analyses indicated that this fragment was homologous with aad gene, which confirmed the resistance to spectinomycin/streptomycin. This is the first report on the presence of integron in the E. coli isolated from the environment. Key words: Integron / antibiotic resistance / Escherichia col
EFFECTS OF CARBOFURAN ON THE REPRODUCTIVE CAPACITY OF A FRESHWATER SNAIL, RADIX QUADRASI, UNDER LABORATORY CONDITIONS
Get PDFThe effects of 4 sublethal concentrations of carbofuran (250, 500, 1000 and 2000 ppm) on the reproductive capacity of R. quadrasi was determined. Results showed that incubation period is delayed and inhibited by 1000 and 2000 ppm carbofuran but not by lower concentrations. The hatching period is longer in treated snails and not all eggs hatch in the 1000 and 2000 ppm treatment. The percentage of hatching is inversely proportional to the carbofuran concentration. Oviposition was delayed in all the treated stages and at all dosages. The higher the carbofuran concentration, the later the onset of oviposition. The reproductive period is shortened. Fecundity was decreased in snails treated at EMB and SM. However, only the 2000 ppm carbofuran concentration showed an adverse effect on the snails exposure at PSM
DIVERSITY AND DISTRIBUTION OF PLASMODIAL MYXOMYCETES (SLIME MOLDS) FROM LA MESA ECOPARK, QUEZON CITY, PHILIPPINES
Get PDFMyxomycetes are ubiquitous in terrestrial forest ecosystems. Thus, this research study looks at the taxonomic diversity and distribution of plasmodial myxomycetes in La Mesa Ecopark in Quezon City, Philippines. A total of 240 moist chambers were prepared from four substrates (aerial and ground leaf litter, twigs and barks) collected within this ecopark. Following incubation of moist chambers for eight weeks, a total of 28 species belonging to 10 genera were collected and identified: Arcyria (3), Diderma (2), Didymium (5), Lamproderma (2), Perichaena (3), Physarum (8), Macbrideola (1), Metatrichia (1), Trichia (1) and Stemonitis (2). Highest myxomycete yield (85%) was observed in aerial leaf litter. In terms of taxonomic diversity, highest diversity was observed in bark microhabitats, although the lowest number of species was recorded in it. Assessment of their abundance and distribution showed similarities in species composition between aerial and ground leaf litter. This research study is the first report of plasmodial myxomycetes in La Mesa Ecopark in Quezon City, Philippines.
Keywords: myxomycetes, slime molds, microhabitats, recreational fores
THE PERFORMANCE OF UPLAND RICE ESTABLISHED ON ALANG-ALANG DOMINATED AREA AFTER VARIOUS TECHNIQUES OF ALANG-ALANG CONTROL
Get PDFPot experiment to investigate the performance of upland rice in a previously alang-alang dominated area was conducted under greenhouse condition at BIOTROP, Bogor, Indonesia from November 1986 to May 1989. The treatments were factorially combined, replicated 5 times and randomized completely. The first factor was alang-alang control consisting of 5 different techniques, i.e. (1) glyphosate applied at 2.2 kg a.e./ha; (2) imazapyr applied at 1.5 kg a.e./ha; (3) dalapon applied twice at 7.4 + 7.4 kg a.i./ha; (4) slashing followed by soil cultivation; (5) slashing of alang-alang only; while the second factor was nitrogen fertilizer at 4 different levels, i.e. (1) 0 kg N/ha, (2) 60 kg N/ha, (3) 120 kg N/ha given twice, 60 kg N/ha at planting time and 60 kg N/ha at 38 dap, (4) 180 kg N/ha given twice, 90 kg N/ha at planting and 90 kg N/ha at 38 dap. Plant height (cm), tiller number/pot, productive tiller (%), panicle length (cm), spikelets/panicle, empty spikelet (%), weight 1000 grains (g) and grain yield (ton/ha) were observed. Upland rice grown with zero tillage technique using glyphosate (2.2 kg a.i./ha) or dalapon (14.8 kg a.i./ha) performed as good as or even better than manual cultivation. Imazapyr at 1.5 kg a.e./ha was phytotoxic to rice planted 1 month after spraying. The application of N fertilizer lower than 60 kg N/ha was not sufficient, but more than 60 kg N/ha was too high; it stimulated the production of too many tillers, with high percentage of unproductive tillers and empty grains
ASPERGILLUS FLA VUS INFECTION AND AFLATOXIN CONTAMINATION IN PEANUTS AT VARIOUS STAGES OF THE DELIVERY CHAINS IN CIANJUR REGENCY, WEST JAVA, INDONESIA
Get PDFA survey to obtain information on pre- and postharvest handling of peanuts at farmer, collector, wholesaler and retailer levels, including Aspergillus flavus infection and aflatoxin BI contamination of peanuts collected in Cianjur regency, West Java, was conducted during the harvest period of the wet season of February 2004. The moisture contents and physical qualities of the peanuts were also determined. Thirteen and 40 dry pod samples were collected randomly from 12 farmers and 23 collectors, respectively. Seven dry kernel samples were also collected from collectors. Five and 45 dry kernel samples were collected randomly from 2 wholesalers and 45 retailers in traditional markets, respectively. Thus, a total of 110 dry peanut pod and kernel samples were collected. The results of interviews with farmers, collectors, wholesalers and retailers, and also the moisture contents and physical qualities of the peanuts arc described in this article. The percentages of samples infected by A. flavus were highest at the wholesaler as well as at retailer levels (100%, respectively), followed by those sampled at the collectors (85.0 and 85.7%, respectively), and farmers (84.6%). The mean percentage of infected kernels in infected samples of peanuts collected from retailers was the highest (87.6%), followed by those collected from wholesalers (72.4%), collectors in the form of kernels (23.3%) and pods (17.7%), and farmers (15.2%). The range of aflatoxin BI contents in peanut samples collected from farmers (dry pods), collectors (dry pods), wholesalers (dry pods and kernels) and retailers (dry kernels) were < 3.6 -114.2, < 3.6 -2999.5 and < 3,6 - 34.1, < 3.6 - 6065.9, and < 3.6 - 6073.0 ppb, respectively. The highest aflatoxin B, contents at the wholesaler and retailer levels were 6065.9 ppb (in one sample) and 6073.0 ppb (in one sample), respectively. The percentage of samples contaminated with more than 15 ppb of aflatoxin BI was the highest in peanuts collected from wholesalers (80.0% of samples), followed by retailers (75.6%), farmers (38.5%) and collectors (30.0 and 14.3%). In 1999 Codex Alimcntarius Commission determined that the maximum total aflatoxin content in peanuts intended for further processing is 15 ppb, suggesting that an alarming proportion of peanuts throughout the Indonesian food chain arc in excess of this maximum limit. Key words : ,4,spergillius flavus/Aflatoxin/Peanuts/Cianjur regenc
THE ROLE OF HALTICA SP. (COLEOPTERA: HALTICIDAE) AS BIOLOGICAL CONTROL AGENT OF POLYGONUM CHINENSE
Get PDFThe role of Haltica sp. (Coleoptera: Halticidae) with emphasis on host specificity and damage potential in controlling Polygonum chinense was evaluated under laboratory condition. Starvation test of the weevil on 33 weeds and 14 crop plant species indicated that only 6 weed species were attacked: Polygonum chinense, P. nepalense, P. barbatum, P. longisetum, Ludwigia octovalvis and L. parennis with P. chinense as the most preferred host plant. Preliminary damage potential test indicated that a population of 0, 1,2 and 3 pairs of adult weevil reduced the percentage of fresh weight increment of P. chinense by   0; 46.2; 74.7 and 75.5% respectively. Field observations indicated that the larvae as well as adult weevils are potential biological control agents of P. chinense. Further studies are, however, on the host-range of this weevil