Displaying publications 1 - 20 of 82 in total

Abstract:
Sort:
  1. Biocontrol of Culex quinquefasciatus using the insect parasitic nematode, Romanomermis iyengari (Nematoda: Mermithidae)
    Abagli AZ, Alavo TBC
    Trop Biomed, 2019 Dec 01;36(4):1003-1013.
    PMID: 33597470
    Cx. quinquefasciatus is a common nuisance mosquito widely distributed in tropical and subtropical areas. This mosquito is also a vector of urban filariasis. Control with chemicals has been hampered by the development of resistance against chemical insecticides and rising problems of environmental contamination associated with them. Therefore, it is important to adopt more integrated mosquito management approaches that include sustainable, non chemical solutions. The mermithid nematode Romanomermis iyengari is one of several natural control alternatives to synthetic pesticides for mosquito suppression. This study evaluated the effectiveness of the nematode R. iyengari for control of Cx. quinquefasciatus. The nematode R. iyengari was mass-produced, and pre-parasitics (J2) were used for laboratory and field experiments. In laboratory experiments, two concentrations of pre-parasitics (5 and 10 J2 per larva) were tested against L1, L2 and L3 instars larvae of Cx. quinquefasciatus. Infected larvae were observed daily to determine their mortality rate and the number of postparasitic nematodes emerging from dead larvae. In field experiments, 1000, 2000 and 3000 J2/m2 were sprayed in separate natural Cx. quinquefasciatus breeding sites. After treatment, the larval mosquito density in the breeding sites was assessed every 5 days. Laboratory results showed that all tested Cx. quinquefasciatus instars larvae were susceptible to nematode infection. The mortality rates observed for each larval stage indicated that the concentration of 10 J2 kills larvae faster, and that the L1 larvae died earlier than older larvae. The average number of post-parasitic nematodes emerging per larva increases with increasing nematode concentration; also more post-parasitic nematodes emerged from the L2 larvae. Field data showed that, in breeding site treated with 3000 J2 per square meter, larval mosquito reduction reached 97% after nematode application. The dosage of 1000 J2 per square meter did not reduce the larval density. The insect parasitic nematode R. iyengari could be easily used as component of integrated mosquitoes control program in lymphatic filariasis endemic countries.
    Matched MeSH terms: Pest Control, Biological/methods*
  2. Sharing Malaysian experience with the development of biotechnology-derived food crops
    Abu Bakar UK, Pillai V, Hashim M, Daud HM
    Food Nutr Bull, 2005 Dec;26(4):432-5.
    PMID: 16465992
    Biotechnology-derived food crops are currently being developed in Malaysia mainly for disease resistance and improved post harvest quality. The modern biotechnology approach is adopted because of its potential to overcome constraints faced by conventional breeding techniques. Research on the development of biotechnology-derived papaya, pineapple, chili, passion fruit, and citrus is currently under way. Biotechnology-derived papaya developed for resistance to papaya ringspot virus (PRSV) and improved postharvest qualities is at the field evaluation stage. Pineapple developed for resistance to fruit black heart disorder is also being evaluated for proof-of-concept. Other biotechnology-derived food crops are at early stages of gene cloning and transformation. Activities and products involving biotechnology-derived crops will be fully regulated in the near future under the Malaysian Biosafety Law. At present they are governed only by guidelines formulated by the Genetic Modification Advisory Committee (GMAC), Malaysia. Commercialization of biotechnology-derived crops involves steps that require GMAC approval for all field evaluations and food-safety assessments before the products are placed on the market. Public acceptance of the biotechnology product is another important factor for successful commercialization. Understanding of biotechnology is generally low among Malaysians, which may lead to low acceptance of biotechnology-derived products. Initiatives are being taken by local organizations to improve public awareness and acceptance of biotechnology. Future research on plant biotechnology will focus on the development of nutritionally enhanced biotechnology-derived food crops that can provide more benefits to consumers.
    Matched MeSH terms: Pest Control, Biological
  3. Fulltext Wolbachia strain wAlbB maintains high density and dengue inhibition following introduction into a field population of Aedes aegypti
    Ahmad NA, Mancini MV, Ant TH, Martinez J, Kamarul GMR, Nazni WA, et al.
    Philos Trans R Soc Lond B Biol Sci, 2021 02 15;376(1818):20190809.
    PMID: 33357050 DOI: 10.1098/rstb.2019.0809
    Aedes aegypti mosquitoes carrying the wAlbB Wolbachia strain show a reduced capacity to transmit dengue virus. wAlbB has been introduced into wild Ae. aegypti populations in several field sites in Kuala Lumpur, Malaysia, where it has persisted at high frequency for more than 2 years and significantly reduced dengue incidence. Although these encouraging results indicate that wAlbB releases can be an effective dengue control strategy, the long-term success depends on wAlbB maintaining high population frequencies and virus transmission inhibition, and both could be compromised by Wolbachia-host coevolution in the field. Here, wAlbB-carrying Ae. aegypti collected from the field 20 months after the cessation of releases showed no reduction in Wolbachia density or tissue distribution changes compared to a wAlbB laboratory colony. The wAlbB strain continued to induce complete unidirectional cytoplasmic incompatibility, showed perfect maternal transmission under laboratory conditions, and retained its capacity to inhibit dengue. Additionally, a field-collected wAlbB line was challenged with Malaysian dengue patient blood, and showed significant blocking of virus dissemination to the salivary glands. These results indicate that wAlbB continues to inhibit currently circulating strains of dengue in field populations of Ae. aegypti, and provides additional support for the continued scale-up of Wolbachia wAlbB releases for dengue control. This article is part of the theme issue 'Novel control strategies for mosquito-borne diseases'.
    Matched MeSH terms: Pest Control, Biological*
  4. Effect of ten chlorophytes on larval survival, development and adult body size of the mosquito Aedes aegypti
    Ahmad R, Chu WL, Ismail Z, Lee HL, Phang SM
    Southeast Asian J. Trop. Med. Public Health, 2004 Mar;35(1):79-87.
    PMID: 15272748
    The effect of ten microalgal chlorophytes isolated from mosquito breeding containers on the survival, larval development and adult body size of the mosquito Aedes aegypti was investigated. All larvae fed with six of the microalgal isolates died after 7 days. These isolates were found to be resistant to digestion by mosquito larvae. Delayed pupation and body size reduction of the mosquitos fed with Chlorococcum UMACC 218 and Scenedesmus UMACC 220 were observed. In contrast, larvae fed with Ankistrodesmus convolutus UMACC 101 and Chlorococcum UMACC 213 were bigger in size than those fed with normal insectory feed. The present study showed that microalgal chlorophytes have the potential to be used as larvicidal agents for mosquitos.
    Matched MeSH terms: Pest Control, Biological/methods*
  5. Genetically modified mosquitoes
    Aldridge S
    Nat Biotechnol, 2008 Jul;26(7):725.
    PMID: 18612284 DOI: 10.1038/nbt0708-725a
    Matched MeSH terms: Pest Control, Biological/methods*
  6. Isolation of Beauveria bassiana Pr-11 from Andean orthopterans and its effectiveness against Chagas disease vectors in Peru
    Castellanos-Sánchez P, Falconi-Agapito F, Pariona N, Paredes-Esquivel C
    Trop Biomed, 2020 Dec 01;37(4):864-870.
    PMID: 33612739 DOI: 10.47665/tb.37.4.864
    Chagas disease is endemic to the Americas and is transmitted by blood-feeding kissing bugs. We evaluated the insecticidal potential of a fungus (Beauveria bassiana strain Pr-11) against Triatoma infestans, an important vector in South America. This fungal species was isolated from a locust (Schistocerca piceifrons) that inhabits the Central Andes region of Peru. Ten days post inoculation, this strain induced high insect mortality (97%) at low fungal concentrations (2 × 107 conidia/ml) at 70% relative humidity. The Pr-11 strain outperformed reference strain CCBLE-216 B. bassiana, provided by the Peruvian Ministry of Agriculture. Our results are consistent with previous reports on the virulence of this fungal strain against other insect pests. This is the first study to evaluate an orthopteran-isolated B. bassiana to control Chagas disease vectors. We conclude that strain Beauveria bassiana Pr-11 is effective against Triatoma infestans, resulting in a promising tool to control Chagas disease in Peru and may be used in integrated vector control programs.
    Matched MeSH terms: Pest Control, Biological/methods*
  7. Fulltext Nematophagous fungi as a biological control agent for nematode parasites of small ruminants in Malaysia: a special emphasis on Duddingtonia flagrans
    Chandrawathani P, Jamnah O, Waller PJ, Höglund J, Larsen M, Zahari WM
    Vet Res, 2002 Nov-Dec;33(6):685-96.
    PMID: 12498569
    Approximately 2,800 fresh dung samples from animals, mainly ruminant livestock, were screened for the presence of nematophagous fungi in Malaysia. Arthrobotrys spp. was noted on numerous occasions, but only one isolate of Duddingtonia flagrans was made. For the purposes of producing sufficient quantities of this fungus for feeding trials in sheep, various, commonly available, cheap plant materials were tested as possible growth substrates. This showed that cereal grains (wheat, millet and rice) were the best media for fungal growth. Pen feeding trials were carried out using sheep, both naturally and experimentally infected with nematode parasites (predominantely Haemonchus contortus), to test the efficiency of D. flagrans when administered either in a grain supplement, or incorporated into a feed block. These showed that the fungus survived gut passage in sheep and that dose rates of approximately 1 x 10(6) D. flagrans spores / animal / day, reduced the percentage of infective larvae developing in faecal cultures by more than 90%. These results indicate that using D. flagrans as a biological control agent of nematode parasites, is a promising alternative to nematode parasite control of small ruminants in Malaysia, where anthelmintic resistance is now a major problem.
    Matched MeSH terms: Pest Control, Biological*
  8. The control of the free-living stages of Strongyloides papillosus by the nematophagous fungus, Arthrobotrys oligospora
    Chandrawathani P, Omar J, Waller PJ
    Vet Parasitol, 1998 Apr 30;76(4):321-5.
    PMID: 9650868
    Two laboratory trials were conducted to determine the effect of the addition of spores (conidia) of the nematophagous fungus, Arthrobotrys oligospora, on the development of the ruminant parasite, Strongyloides papillosus, in cultures of bovine faeces. Both studies showed that at a concentration of 2000 conidia/g faeces virtually eliminated infective larvae (> 99% reduction), following 14 days incubation under ideal conditions (25 degrees C and saturated humidity) for free-living development of this parasite species. In one trial, a high level of control was also observed at a 10-fold decrease in conidia concentration (200 spores/g faeces). This work has demonstrated, in principle, that A. oligospora could provide a practical biological control agent against S. papillosus infecting intensively raised young ruminants in the humid tropics/subtropics.
    Matched MeSH terms: Pest Control, Biological*
  9. Field studies on the biological control of nematode parasites of sheep in the tropics, using the microfungus Duddingtonia flagrans
    Chandrawathani P, Jamnah O, Adnan M, Waller PJ, Larsen M, Gillespie AT
    Vet Parasitol, 2004 Mar 25;120(3):177-87.
    PMID: 15041093
    Long-term field studies were conducted on two government managed small ruminant research farms, located in different geo-climatic regions and approximately 300 km separate from each other, on Peninsula Malaysia. The Infoternak trial (48 weeks) and the Chalok trial (43 weeks) each compared nematode parasite control in separately managed groups of young sheep, either short-term rotationally grazed around a suite of 10 paddocks in addition to receiving a daily supplement of Duddingtonia flagrans spores (Fungus Group); or similar groups of sheep being rotationally grazed alone (Control Group). The prevailing weather conditions at Infoternak farm were of below average rainfall conditions for the most of the trial. As a consequence, only very low worm infections (almost exclusively Haemonchus contortus) were acquired by the 17 sets of tracer lambs that grazed sequentially with the experimental lambs. However on all except 2 occasions in the early part of the trial, the mean tracer worm burdens were significantly lower (P < 0.05) and the experimental lambs grew significantly better (P = 0.054) in the Fungus Group. Rainfall at Chalok farm during the course of the trial was also below average. As a consequence infectivity of pastures was assumed to be relatively low based on faecal egg counts (epg) of the experimental sheep, which following an anthelmintic treatment prior to allocation, remained very low in both treatment groups. Faecal egg counts of undosed replacement lambs in the latter half of the Chalok study, showed a progressive increase in the Control Group to levels exceeding 3000 epg, whereas the Fungus Group remained static at approximately 500 epg. These results show that the deployment of the nematophagous fungus, D. flagrans, can improve the level of parasite control of sheep in the tropics above that which can be achieved by the short-term rotational grazing strategy alone.
    Matched MeSH terms: Pest Control, Biological/methods*
  10. Biological control of nematode parasites of small ruminants in Malaysia using the nematophagous fungus Duddingtonia flagrans
    Chandrawathani P, Jamnah O, Waller PJ, Larsen M, Gillespie AT, Zahari WM
    Vet Parasitol, 2003 Nov 14;117(3):173-83.
    PMID: 14630426
    Control of nematode parasites of small ruminants in a wet, tropical environment using the nematophagous fungus, Duddingtonia flagrans, was assessed in this study. Two methods of fungal delivery were tested, namely as a daily feed supplement, or incorporated into feed blocks. Initially, pen trials were conducted with individually penned groups of sheep and goats at dose rates of 125,000 spores and 250,000 spores/kg live weight per day. At the lower dose rate this reduction was between 80 and 90% compared with the pre-treatment levels. At the higher dose rate, there was virtually complete suppression (>99% reduction) of larval recovery. Trials using the fungal feed blocks, showed that when animals were individually penned, they consumed only small amounts of the block (particularly goats), hence little effect on larval recovery in faecal cultures was observed. Grouping animals according to species and dose rate induced satisfactory block consumption and subsequent high levels of larval reduction in faecal cultures. These larval reductions were mirrored by the presence of fungus in faecal cultures. This work was followed by a small paddock trial, whereby three groups of sheep were fed either a feed supplement without fungal spores, supplement with spores, or offered fungal blocks. The dose rate of spores in the latter two groups was 500,000 spores/kg live weight per day. Egg counts were significantly reduced in the two fungal groups, compared with the control group and the latter required two salvage anthelmintic treatments to prevent mortality due to haemonchosis. Pasture larval numbers on the two fungal group plots were also much lower than on the control plot.
    Matched MeSH terms: Pest Control, Biological*
  11. The effect of Bacillus thuringiensis israelensis [H-14] on emergence of Mansonia mosquitos from natural breeding habitat
    Chang MS, Ho BC, Chan KL
    Southeast Asian J. Trop. Med. Public Health, 1990 Sep;21(3):430-6.
    PMID: 1981631
    The measurement of the ultimate effects of the microbial insecticides on mosquito density is best obtained by assessment of adult populations. The main aims of this study are: (1) to assess the effect of Bacillus thuringiensis israelensis (Bti) FC Skeetal and Bactimos briquettes on the emergence rate of Mansonia bonneae developed from the introduced first-instar stage larvae and (2) to measure the effect of these two formulations of insecticides on Mansonia adult populations emerging from the natural breeding plots. Bti Skeetal and Bactimos briquettes at the lower applied dosages of 2.3 kg/ha and 1 briquette case/20 m2 respectively achieved 39-40% pupation rates and 31.5-34.2% adult emergence rates. At these low applied dosages, there was little or no direct effect on pupation from the surviving larvae and thereafter on the emergence of adults from the pupae. A two-fold increase in dosage, however, produced a drastic decline in the pupation rate and adult emergence rate. The rates dropped to 6.5% (pupation) and 4.3% (adult emergence) of the total larvae for Bactimos briquettes and to merely 1.5% (pupation) and 1.3% (adult emergence) of the total larvae for Skeetal. In studying the effect of Bti on the field populations of Mansonia mosquitos, two plots each were treated with Bactimos at 1 briquette case/10 m2 and Skeetal at 4.6 kg/ha. A wooden pyramid-shaped screened cage was placed on a cluster of host plants for a period of 2 weeks to trap the emerging adult mosquitoes. There were a total of 24 clusters of host plants in each plot.(ABSTRACT TRUNCATED AT 250 WORDS)
    Matched MeSH terms: Pest Control, Biological*
  12. Lack of involvement of chitinase in direct toxicity of Beauveria bassiana cultures to the aphid Myzus persicae
    Cheong PCH, Glare TR, Rostás M, Haines S, Brookes JJ, Ford S
    J Invertebr Pathol, 2020 01;169:107276.
    PMID: 31715183 DOI: 10.1016/j.jip.2019.107276
    The fungal insect pathogen Beauveria bassiana produces a range of insecticidal metabolites and enzymes, including chitinases and proteases, which may assist the disease progression. The enzymes often play a predominant role in the pathogenicity pathway and both chitinases and proteases have previously been shown to be important in host infection. Spray application of supernatants of B. bassiana broth cultures of an isolate from New Zealand caused significant mortality in the green peach aphid, Myzus persicae, within 24 h, demonstrating an apparent contact toxicity. Three-day-old broth cultures were the most effective, with less insect mortality seen using six-day-old broth. However, aphicidal activity increased again when treating aphids with seven-day-old broth. Cultures grew substantially better and produced more potent aphicidal cultures when cultured in media with an initial pH above 5.5. Chitinase was produced a day earlier than the serine protease Pr1, but the peak production periods of these enzymes did not correlate with the aphicidal activities of three- or six-day-old cultures. Cultures treated with EDTA or heated to inactivate the enzymes still showed strong insecticidal activity. Neither beauvericin nor bassianolide, two known insecticidal metabolites, were detected in the supernatants. Therefore the key aphicidal components of B. bassiana cultures were not associated with chitinase nor Pr1 and are yet to be identified.
    Matched MeSH terms: Pest Control, Biological*
  13. Bioassays of Bacillus sphaericus (strain 1593) against mosquitoes of public health importance in Malaysia
    Cheong WC, Yap HH
    Southeast Asian J. Trop. Med. Public Health, 1985 Mar;16(1):54-8.
    PMID: 4023816
    The pathogenicity of Bacillus sphaericus strain 1593 was tested against laboratory-reared larvae of four local species of mosquitoes of public health importance in Malaysia; Aedes aegypti, Anopheles balabacensis, Mansonia uniformis and Culex quinquefasciatus. The bacteria was shake-cultured at 28 +/- 1 degrees C for three days, using Glucose-Yeast Extract Salts medium. After which, the spores and vegetative cells were harvested and stored at 4 degrees C before use. Conditions for bioassays were mean temperature of 25 +/- 1 degrees C and relative humidity 65 +/- 5.0. Twenty third-instar larvae of each species were assayed in 90 ml of diluted spore solution. Each concentration and a control were replicated three times for each bioassay. Larval mortalities at 24 hours and 48 hours were taken and analyzed through Probit Analysis using a computer (IBM 370). LC50 values after 48 hours of exposure showed an increasing order of larval susceptibility as follows: Ae. aegypti (417.70 x 10(4)), An. balabacensis (45.84 x 10(4)), Ma. uniformis (18.23 x 10(4)) and Cx. quinquefasciatus (4.14 x 10(4) spores/ml). With the ability to kill 90% of the Cx. quinquefasciatus larvae tested with just a concentration of 10(5) spores/ml, B. sphaericus (strain 1593) has shown good potential as a biocontrol agent for this species of mosquito.
    Matched MeSH terms: Pest Control, Biological*
  14. Comparative susceptibility of five strains of Mansonia uniformis (Diptera:Culicidae) in Malaysia to infection with subperiodic Brugia malayi
    Chiang GL, Loong KP, Eng KL
    Southeast Asian J. Trop. Med. Public Health, 1989 Jun;20(2):169-74.
    PMID: 2575285
    Five strains of Ma. uniformis from Malaysia were tested for their susceptibility to infection with subperiodic B. malayi. All were found to be susceptible with infection rates ranging from 62% to 100%. The susceptibility rates were directly related to the microfilarial densities of the cat at the time of feeding. Statistical analysis showed no significant difference (p greater than 0.05) among the means of the indices of experimental infection as well as the percentage of infective mosquitoes of the five strains and an old laboratory colony. They were all equally susceptible to subperiodic B. malayi.
    Matched MeSH terms: Pest Control, Biological
  15. Survey of microsporidan hyperparasites of trematode larvae from Malaysian snails
    Colley FC, Ow-Yang CK
    Southeast Asian J. Trop. Med. Public Health, 1973 Jun;4(2):270-1.
    PMID: 4201357
    Matched MeSH terms: Pest Control, Biological
  16. Fulltext Courtship activity, copulation & insemination success in a mosquito vector fed a herbal aphrodisiac: Implications for sterile insect technology
    Dieng H, Satho T, Abang F, Miake F, Azman FAB, Latip NA, et al.
    Indian J Med Res, 2018 Sep;148(3):334-340.
    PMID: 30425225 DOI: 10.4103/ijmr.IJMR_1604_16
    Background & objectives: In sterile insect technology (SIT), mating competitiveness is a pre-condition for the reduction of target pest populations and a crucial parameter for judging efficacy. Still, current SIT trials are being hindered by decreased effectiveness due to reduced sexual performance of released males. Here, we explored the possible role of a herbal aphrodisiac in boosting the mating activity of Aedes aegypti.

    Methods: Males were fed one of two diets in this study: experimental extract of Eurycoma longifolia (MSAs) and sugar only (MSOs). Differences in life span, courtship latency, copulation activity and mating success were examined between the two groups.

    Results: No deaths occurred among MSA and MSO males. Life span of MSOs was similar to that of MSAs. The courtship latency of MSAs was shorter than that of MSOs (P<0.01). MSAs had greater copulation success than MSOs (P<0.001). In all female treatments, MSAs mated more than MSOs, but the differences in rate were significant only in the highest female density (P<0.05). In MSAs, mating success varied significantly with female density (P<0.01), with the 20-female group (P<0.01) having the lowest rate. Single MSA had better mating success at the two lowest female densities. In MSOs, there were no significant differences in mating success rate between the different female densities.

    Interpretation & conclusions: Our results suggested that the herbal aphrodisiac, E. longifolia, stimulated the sexual activity of Ae. aegypti and may be useful for improving the mating competitiveness of sterile males, thus improving SIT programmes.

    Matched MeSH terms: Pest Control, Biological/methods*
  17. Biological control of Phlebotomus papatasi larvae by using entomopathogenic nematodes and its symbiotic bacterial toxins
    El-Sadawy HA, Ramadan MY, Abdel Megeed KN, Ali HH, El Sattar SA, Elakabawy LM
    Trop Biomed, 2020 Jun 01;37(2):288-302.
    PMID: 33612799
    The sand fly Phlebotomus papatasi is an important disease-bearing vector. Five entomopathogenic nematodes (EPNs) - Steinernema carpocapsae DD136, Steinernema sp. (SII), S. carpocapsae all, S. abbasi, and Heterorhabditis bacteriophora HP88 - were applied as biocontrol agents against the late third instar larvae of P. papatasi. In addition, the effect of toxin complexes (TCs) of Xenorhabdus nematophila and Photorhabdus luminescens laumondii bacteria was evaluated. Results revealed that S. carpocapsae DD136 was the most virulent species followed by Steinernema sp. (SII) and S. carpocapsae all where LC50 were 472, 565, 962 IJs/ml, respectively. Also, the crude TCs were slightly more active and toxic than their fractionated protein. Histopathological examination of infected larvae with H. bacteriophora HP88 showed negative effect on their midgut cells. In conclusion, EPNs with their symbiotic bacteria are more effective as biocontrol agents than the crude or fractionated TCs against sand fly larvae.
    Matched MeSH terms: Pest Control, Biological*
  18. Screening of nematophagous-fungi from fresh faeces of grazing animals and soils
    Farah Haziqah MT, Nur Hikmah AM, Mat Hasan H, Hamdan A, Nik Him NAII
    Trop Biomed, 2019 Sep 01;36(3):687-693.
    PMID: 33597490
    An investigation was undertaken for screening and isolating nematophagous-fungi from the faecal samples of various grazing animals and soils in Malaysia. Total of 111 faeces and 50 soil samples were collected and the samples were cultured on 2% water agar plates. The growth of nematophagous-fungi was stimulated by sprinkling-baiting technique. The conidia of suspected nematophagous-fungi were inoculated on 2% water agar plates. All isolated were maintained on 2% cornmeal agar plates. Verticillium spp., Fusarium spp. and Arthrobotrys spp. were identified from the faecal and soil samples. 62.5% of the faecal samples and 100% of the soil samples were shown to be positive with nematophagous-fungi. This study highlights the present of nematophagous-fungi population in faecal and soil samples. Much study remains to be done to better understanding some fungi especially their mode of action and their predatory behaviour against parasitic nematodes.
    Matched MeSH terms: Pest Control, Biological
  19. Before and after Silent Spring: from chemical pesticides to biological control and integrated pest management--Britain, 1945-1980
    Gay H
    Ambix, 2012 Jul;59(2):88-108.
    PMID: 23057183
    The use of chemical pesticides increased considerably after World War II, and ecological damage was noticeable by the late 1940s. This paper outlines some ecological problems experienced during the post-war period in the UK, and in parts of what is now Malaysia. Also discussed is the government's response. Although Rachel Carson's book, Silent Spring (1962), was important in bringing the problems to a wider public, she was not alone in sounding the alarm. Pressure from the public and from British scientists led, among other things, to the founding of the Natural Environment Research Council in 1965. By the 1970s, environmentalism was an important movement, and funding for ecological and environmental research was forthcoming even during the economic recession. Some of the recipients were ecologists working at Imperial College London. Moved by the political climate, and by the evidence of ecological damage, they carried out research on the biological control of insect pests.
    Matched MeSH terms: Pest Control, Biological/history*; Pest Control, Biological/methods; Pest Control, Biological/standards
  20. Antagonistic effects of Streptomyces violaceusniger strain G10 on Fusarium oxysporum f.sp. cubense race 4: indirect evidence for the role of antibiosis in the antagonistic process
    Getha K, Vikineswary S
    J Ind Microbiol Biotechnol, 2002 Jun;28(6):303-10.
    PMID: 12032802
    Fusarium oxysporum f.sp. cubense is the causal pathogen of wilt disease of banana. A cost-effective measure of control for this disease is still not available. Streptomyces violaceusniger strain G10 acts as an antifungal agent antagonistic towards many different phytopathogenic fungi, including different pathogenic races of the Fusarium wilt pathogen. In an attempt to understand the mode of action of this antagonist in nature, the interaction between S. violaceusniger strain G10 and F. oxysporum f.sp. cubense was first studied by paired incubation on agar plates. Evidence for the in vitro antibiosis of strain G10 was demonstrated by inhibition zones in the "cross-plug" assay plates. Microscopic observations showed lysis of hyphal ends in the inhibited fungal colonies. Culture of strain G10 in liquid media produces antifungal metabolites, which showed in vitro antagonistic effects against F. oxysporum f.sp. cubense such as swelling, distortion and excessive branching of hyphae, and inhibition of spore germination. An indirect method was used to show that antibiosis is one of the mechanisms of antagonism by which strain G10 acts against F. oxysporun f.sp. cubense in soil. This study suggests the potential of developing strain G10 for the biological control of Fusarium wilt disease of banana.
    Matched MeSH terms: Pest Control, Biological
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links