Microbial Control Of Insect Pests Research Articles

Efficacy of different entomopathogenic fungal isolates against chilli aphid, Myzus Persicae (Sulz.)

In recent years, microbial control of insect pests is becoming popular as insect pathogens such as bacteria, viruses, fungi and nematodes serve as potential bioagents in pest management. Among the different microbial agents, entomopathogenic fungi (EPF) are gaining importance in pest control. They can be easily mass cultured on artificial media without affecting their virulence at a cheaper cost. They are highly species specific with minimal impact on non-target organisms. The current study aimed to study the efficacy of entomopathogenic fungal isolates against aphid, Myzus Persicae (Sulz.) in chilli. Laboratory and field experiments were conducted to evaluate the pathogenicity of Beauveria bassiana, Metarhizium anisopliae and Lecanicillium lecanii against chilli aphid. From the study it is revealed that B. bassiana @ 108 spores ml-1 were found to be effective and found to be more superior to the other entomopathogenic fungal isolates viz., Metarhizium anisopliae and Lecanicillium lecanii against chilli aphid.

Entomopathogenic Fungi: Factors Involved in Successful Microbial Control of Insect Pests

Entomopathogenic Fungi: Factors Involved in Successful Microbial Control of Insect Pests

Species clarification of Isaria isolates used as biocontrol agents against Diaphorina citri (Hemiptera: Liviidae) in Mexico

Entomopathogenic fungi belonging to the genus Isaria (Hypocreales: Cordycipitaceae) are promising candidates for microbial control of insect pests. Currently, the Mexican government is developing a biological control program based on extensive application of Isaria isolates against Diaphorina citri (Hemiptera: Liviidae), a vector of citrus huanglongbing disease. Previous research identified three promising Isaria isolates (CHE-CNRCB 303, 305, and 307; tentatively identified as Isaria fumosorosea) from Mexico. The goal of this work was to obtain a complete morphological and molecular characterization of these isolates. Comparative analysis of morphology established that the isolates showed similar characteristics to Isaria javanica. Multi-gene analysis confirmed the morphological identification by including the three isolates within the I. javanica clade. Additionally, this work demonstrated the misidentifications of three other Isaria isolates (CHE-CNRCB 310 and 324: I. javanica, formerly I. fumosorosea; CHE-CNRCB 393: I. fumosorosea, formerly Isaria farinosa), underlying the need for a full and correct characterization of an isolate before developing a biological control program. Finally, the inter-simple sequence repeat (ISSR) genotyping method revealed that the CHE-CNRCB 303, 305, and 307 isolates belong to three different genotypes. This result indicates that ISSR markers could be used as a tool to monitor their presence in field conditions.

Microbial Control of Insect Pests in Temperate Orchard Systems: Potential for Incorporation into IPM

Because of their selectivity and safety, microbial control agents (MCAs) appear to be ready-made components of integrated pest management (IPM) systems that do not pose a threat to applicators or the environment and allow other natural enemies to function. Control of several orchard pest insects using MCAs, including viruses, Bacillus thuringiensis, fungi, and entomopathogenic nematodes (EPNs), have been demonstrated in apple, pear, stone fruits, citrus, and several nut crops. B. thuringiensis is the most used MCA for control of lepidopteran orchard pests. Significant use of EPNs in citrus for control of root weevils is also reported. The granulovirus of codling moth is used increasingly in apple and pear by organic growers, with interest also shown by conventional growers. Although some success has been achieved, in most orchard systems MCAs account for a relatively small proportion of the pest control tactics employed, and in some systems they are not used at all. Research toward improving MCA efficacy and economic competitiveness is required to enhance the role of MCAs in IPM.

Can fungal biopesticides control malaria?

Recent research has raised the prospect of using insect fungal pathogens for the control of vector-borne diseases such as malaria. In the past, microbial control of insect pests in both medical and agricultural sectors has generally had limited success. We propose that it might now be possible to produce a cheap, safe and green tool for the control of malaria, which, in contrast to most chemical insecticides, will not eventually be rendered useless by evolution of resistance. Realizing this potential will require lateral thinking by biologists, technologists and development agencies.

New use of broomcorn millets for production of granular cultures of aphid-pathogenic fungus Pandora neoaphidis for high sporulation potential and infectivity to Myzus persicae

Glutinous broomcorn millets from the crop Panicum miliaceum were first used as substrate to produce granular cultures of Pandora neoaphidis, an obligate fungal pathogen specific to aphids. Carrying a water content of 36.5% after being steamed in a regular autoclaving procedure, millet grains of each 15 g (dry weight) in a 100-ml flask were mixed with 3 ml modified Sabouraud dextrose broth containing half a mashed colony of P. neoaphidis grown on egg yolk milk agar and then incubated at 20°C and a light/dark cycle of 12 h/12 h for 21 days. Based on individually monitoring conidial production potential of 20 millet grains sampled from an arbitrarily taken flask at 3-day intervals, the millet cultures incubated for 6–15 days were capable of producing 16.8–23.4×10 4 conidia per millet grain with conidial ejection lasting for up to 6 days. The cultured millet grains individually produced significantly more conidia than apterous adults of Myzus persicae killed by P. neoaphidis (8.4×10 4 conidia per cadaver) and sporulated twice longer. The modeling of time–dose–mortality data from bioassays on M. persicae apterae exposed to conidial showers from the cultured millet grains and the mycelial mats produced in liquid culture resulted in similar estimates of LC 50 (millets: 21.4, 7.3, and 4.9 conidia mm −2 on days 5–7 after exposure; mycelial mats: 22.1, 10.6, and 7.7 conidia mm −2) although the LT 50 estimated at a given conidial concentration was slightly smaller for the millet cultures than for the mycelial mats. This indicates that the millet grains cultured with P. neoaphidis produced conidia as infective as or slightly more infective to M. persicae than those from the mycelial mats. Based on the sporulation potential, infectivity, and ease and cost of the millet cultures, the method developed in this study highly improved in vitro cultures of P. neoaphidis and may adapt to culturing other entomophthoralean fungi for microbial control of insect pests.

Factors in the Success and Failure of Microbial Controlagents for Soil Dwelling Pests

The soil, being rich in microbes, should be an ideal environment in which to practise microbial control of insect pests, but relatively few organisms have been developed into successful microbial control agents for soil pests. Difficulty arises in implementation of microbial control, as the soil is a highly complex, competitive environment where survival of applied microbes is by no means assured. In addition, soil dwelling pests appear to show a high level of resistance to broad spectrum pathogens and microbial toxins. However, some significant successes have been achieved with bacteria, fungi and nematodes for control of a range of soil inhabiting pest species. The successful microbial controls are based on highly specific microbial/insect interactions where co-evolved pathogens can overcome the host's defences. These agents also have the ability to persist in the soil, either through the inherent stability of the organism or from recycling through the host population. While strain selection for high levels of pathogenicity and environmental competence is the essential first step in microbial control of soil dwelling pests, it must be followed by development of efficient production systems and quality control measures to ensure application of standardised, high quality products. Success in microbial control of soil dwelling pests depends on an appropriate combination of these factors, with failure likely to occur if any one of these essential components is overlooked.

Experimental evidence that refuges delay insect adaptation to Bacillus thuringiensis

Restricted accessMoreSectionsView PDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmail Cite this article Liu Yong-Biao and Tabashnik Bruce E. 1997Experimental evidence that refuges delay insect adaptation to Bacillus thuringiensisProc. R. Soc. Lond. B.264605–610http://doi.org/10.1098/rspb.1997.0086SectionRestricted accessExperimental evidence that refuges delay insect adaptation to Bacillus thuringiensis Yong-Biao Liu Yong-Biao Liu Department of Entomology, University of Hawaii, Honolulu, Hawaii 96822 [email protected] Google Scholar Find this author on PubMed Search for more papers by this author and Bruce E. Tabashnik Bruce E. Tabashnik Department of Entomology, University of Hawaii, Honolulu, Hawaii 96822 Google Scholar Find this author on PubMed Search for more papers by this author Yong-Biao Liu Yong-Biao Liu Department of Entomology, University of Hawaii, Honolulu, Hawaii 96822 [email protected] Google Scholar Find this author on PubMed Search for more papers by this author and Bruce E. Tabashnik Bruce E. Tabashnik Department of Entomology, University of Hawaii, Honolulu, Hawaii 96822 Google Scholar Find this author on PubMed Search for more papers by this author Published:22 April 1997https://doi.org/10.1098/rspb.1997.0086AbstractTheoretical projections suggest that refuges from exposure can delay insect adaptation to environmentally benign insecticides derived from Bacillus thuringiensis, but experimental tests of this approach have been limited. We tested the refuge tactic by selecting two sets of two colonies of diamondback moth (Plutella xylostella) for resistance to B. thuringiensis; subsp. aizawai in the laboratory. In each set, one colony was selected with no refuge and the other with a 10 per cent refuge from exposure to B. thuringiensis subsp. aizawai. Bioassays conducted after nine selections were completed show that mortality caused by B. thuringiensis subsp. aizawai was significantly greater in the refuge colonies than in the no–refuge colonies. These results demonstrate that the refuges delayed the evolution of resistance. Relative to a susceptible colony, final resistance ratios were 19 and 8 for the two no–refuge colonies compared to 6 and 5 for the refuge colonies. The mean realized heritability of resistance to B. thuringiensis subsp. aizawai was 0.046 for colonies without refuges, and −0.002 for colonies with refuges. Selection with B. thuringiensis subsp. aizawai decreased susceptibility to B. thuringiensis toxin Cry1Ab, but not to Cry1 C or B. thuringiensis subsp. kurstaki Although the ultimate test of refuges will occur in the field, the experimental evidence reported here confirms modelling results indicating that refuges can slow the evolution of insect resistance to B. thuringiensis Previous ArticleNext Article VIEW FULL TEXT DOWNLOAD PDF FiguresRelatedReferencesDetailsCited by Morishita M (2019) High-Dose/Refuge Strategy for Insect Resistance to Bt Crops害虫のBt作物抵抗性に対する高濃度/保護区戦略, Japanese Journal of Applied Entomology and Zoology, 10.1303/jjaez.2019.29, 63:2, (29-38), Online publication date: 25-May-2019. 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Cavanagh A, Adler L and Hazzard R Buttercup Squash Provides a Marketable Alternative to Blue Hubbard as a Trap Crop for Control of Striped Cucumber Beetles (Coleoptera: Chrysomelidae), Environmental Entomology, 10.1603/EN10056, 39:6, (1953-1960) Ferré J, Van Rie J and Macintosh S (2008) Insecticidal Genetically Modified Crops and Insect Resistance Management (IRM) Integration of Insect-Resistant Genetically Modified Crops within IPM Programs, 10.1007/978-1-4020-8373-0_3, (41-85), . Onstad D and Knolhoff L (2008) Arthropod Resistance to Crops Insect Resistance Management, 10.1016/B978-012373858-5.50011-3, (185-208), . LIANG G, WU K, RECTOR B and GUO Y (2007) Diapause, cold hardiness and flight ability of Cry1Ac-resistant and -susceptible strains of Helicoverpa armigera (Lepidoptera: Noctuidae), European Journal of Entomology, 10.14411/eje.2007.088, 104:4, (699-704), Online publication date: 15-Oct-2007. 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Ahmed T, Hyder M, Liaqat I and Scholz M (2019) Climatic Conditions: Conventional and Nanotechnology-Based Methods for the Control of Mosquito Vectors Causing Human Health Issues, International Journal of Environmental Research and Public Health, 10.3390/ijerph16173165, 16:17, (3165) Teng H, Yuan Y, Zhang T, Chang X, Wang D and Desneux N (2020) Evaluation of the sublethal effect of tetrachlorantraniliprole on Spodoptera exigua and its potential toxicity to two non-target organisms, PLOS ONE, 10.1371/journal.pone.0242052, 15:11, (e0242052) This Issue22 April 1997Volume 264Issue 1381 Article InformationDOI:https://doi.org/10.1098/rspb.1997.0086Published by:Royal SocietyPrint ISSN:0962-8452Online ISSN:1471-2954History: Published online22/04/1997Published in print22/04/1997 License: Citations and impact Large datasets are available through Proceedings B's partnership with Dryad

Current developments in microbial control of insect pests and prospects for the early 21st century

The role of microbial control in crop and forest protection and the abatement of insects of medical and veterinary importance has expanded considerably with the discovery and development of new microbial control agents and genetic improvement in bacterial and viral pathogens, and improvements in formulation, application options and compatibility with other interventions. A synopsis of the literature regarding the current use of bacteria, viruses, fungi, protozoans and nematodes as microbial control agents is presented along with speculation on their potential in the early 21st century. The most widely used of all microbial control agents isBacillus thuringiensis. The isolation within the past two decades of new strains that are larvicidal for certain Diptera and Coleoptera has increased the utility of the bacterium considerably. Further improvements in efficacy and broadening of its host range are in progress with the isolation of strains with new toxins and the manipulation ofB. thuringiensis genes that encode toxin production using both recombinant and nonrecombinant methods. Genetic manipulation of these genes has also enabled their incorporation into crop plants. The development and commercial availability of entomopathogenic nematodes in the families Steinernematidae and Heterorhabditidae expands the options for the control of insects, especially those with soil inhabiting stages. The results of natural epizootics of fungi and viruses often obviate the requirement for additional interventions. Breakthroughs in understanding the genetics ofBaculovirus and subsequent gene manipulation have increased their virulence and utility. Improved production methods that utilize insect cell culture technology may enable affordable use ofBaculovirus in the not too distant future. Fungi continue to offer the only control options using entomopathogens against plant sucking insects. Although fungi have great potential for development as microbial control agents, only a few have been used on an operational scale. Some factors that might limit the full range of entomopathogen potential, including development of resistance, are discussed. Because of their selectivity and minimal environmental impact, microbial control agents will be ideal components of integrated pest management programs in the early 21st century and beyond. However, if they are used merely as replacements for chemical pesticides, then eventually these agents will face some of the same fate as the chemicals they replace, particularly with respect to resistance.

History, Use, and Future of Microbial Insecticides

ALTHOUGH MICROBIAL INSECTICIDES account for <1% of the total insecticide market, microbial control of insect pests is gaining in importance. This is because of the improved performance and cost competitiveness of microbials in addition to increasing arthropod resistance to chemical insecticides, environmental concerns, and lack of development of new insecticidal chemistries. The use of microbial insecticides is growing at a rapid pace of 10–25% per year compared with chemical insecticides at 1–2% per year. Bacillus thuringiensis Berliner is primarily responsible for this growth. Microbial pest control agents including plants genetically engineered to produce pesticidal chemicals represent the largest number of recent registrations obtained by industry. Currently there are 20 microbial pesticides registered with the Environmental Protection Agency (EPA) (Table 1). Since 1984, EPA has reviewed 44 applications for small-scale field testing of genetically modified microbial pesticides. Since 1986, EPA has reviewed 40 applications for small-scale field testing of transgenic pesticidal plants.

Analysing dose‐mortality data when doses are subject to error

SummaryIn microbial control of insect pests, the dose of pathogen that a subject actually receives varies because of variation in individual intakes. Variation in intake of a given concentration is equivalent to varying the concentration for a given intake. The main effect of such variation is to flatten the dose‐response curve. If the dose‐variation is known, a correction for this effect can be made; new estimates for the slope and intercept of the probit line are given. However, the correction increases the variance of the estimates. The theory is illustrated with an example in which the diamond‐backed month, Plutella xylostella, was fed varying doses of the specific granulosis virus PxGV; intake assays using similar larvae showed the coefficient of variation of intake volume to be about 40%. Simulation studies showed that correction may be practically important only for the estimation of extreme percentiles, e.g. LD95s.

Review—microbial control of insect pests

KALMAKOFF. J.; LONGWORTH, J. F. (compilers) 1981: Microbial control of insect pests. A record of lectures and practical classes presented at a UNESCO/UNEP/ICRO Regional Training Course, Dunedin, New Zealand, August 1977. New Zealand Department of Scientific and Industrial Research bulletin 228, xiv + 102 p. ISSN 0077-961X; ISBN 0-447-06672-0. Price: NZ$28.00; postage $1.50 overseas, 60c within New Zealand. Available from: Science Information Division, DSIR, P.O. Box 9741, Wellington, New Zealand. Reviewed by T. K. Crosby

Evaluation and Optimization of Agro-industrial Wastes for Conidial Production of Metarhizium anisopliae isolates under Solid State Fermentation

Metarhizium anisopliae is known to cause high level of epizootics for more than 200 insect species in versatile agro-ecologies. Concerns on environmental pollution and resistance development to chemical insecticides need environmentally safe and economically viable approaches. Therefore, here we investigate a cheap and large scale industrial production of virulent enthomopathogenes on agricultural wastes. Three Metarhizium anisopliae isolates were grown on agricultural wastes to evaluate their conidia production potential under Solid state fermentation (SSF) technique. Coffee husk, tea waste, wheat bran and vegetable wastes were used as substrates to determine their capability for maximum conidiation of the isolates. Among these, vegetable wastes were the best media to yield 5.80 ±0.72 (107), 4.44±0.55 (107) and 5.58±0.66 (107) conidia/gram of substrate under quantitative assessment for isolate AUMI1, AUMI2 and AUMI3 respectively, at 60% moisture content.  Statistically on two sample t-test vegetable wastes shows significant difference in conidia production when compared to 2 mm and 4 mm sized coffee husk used as substrates. The optimization for temperature indicated that all substrates supported their maximum conidia yield within 27 – 300C range of temperature. The 3.5 pH value used in the present study for optimization was best favored only for coffee husk as substrate. The high conidia yielding substrates were best productive at pH 6.29, 6.63 and 5.4 for vegetable wastes, wheat bran and tea waste, respectively. All isolates incubated on wheat bran was highly productive under sufficient exposure to light. AUMI1 produced high conidia under exposure to light while the higher yield of AUMI2 and AUMI3 was produced under dark condition on vegetable wastes. Therefore, as successful microbial control of insect pests depends on large scale and cheap industrial productivity, cultivation on vegetable wastes and wheat bran under SSF can be a plausible solution.

Review on microbial control of insect pests in forests in Japan

In Japan, two different serious defoliators were controlled by viruses:Dendrolimus spectabilis using cytoplasmic polyhedrosis virus andLymantria fumida using cytoplasmic and nuclear polyhedrosis viruses.

Microbial Control of Insect Pests

Microbial Control of Insect Pests