Home About us Contact
|
Home About us Contact | ||
|
|
||
Pest Management (pest + management)
Kinds of Pest Management Terms modified by Pest Management Selected AbstractsBROADENING THE APPLICATION OF EVOLUTIONARILY BASED GENETIC PEST MANAGEMENTEVOLUTION, Issue 2 2008Fred Gould Insect- and tick-vectored diseases such as malaria, dengue fever, and Lyme disease cause human suffering, and current approaches for prevention are not adequate. Invasive plants and animals such as Scotch broom, zebra mussels, and gypsy moths continue to cause environmental damage and economic losses in agriculture and forestry. Rodents transmit diseases and cause major pre- and postharvest losses, especially in less affluent countries. Each of these problems might benefit from the developing field of Genetic Pest Management that is conceptually based on principles of evolutionary biology. This article briefly describes the history of this field, new molecular tools in this field, and potential applications of those tools. There will be a need for evolutionary biologists to interact with researchers and practitioners in a variety of other fields to determine the most appropriate targets for genetic pest management, the most appropriate methods for specific targets, and the potential of natural selection to diminish the effectiveness of genetic pest management. In addition to producing environmentally sustainable pest management solutions, research efforts in this area could lead to new insights about the evolution of selfish genetic elements in natural systems and will provide students with the opportunity to develop a more sophisticated understanding of the role of evolutionary biology in solving societal problems. [source] DENT, D: Insect Pest Management.JOURNAL OF APPLIED ENTOMOLOGY, Issue 5 20012nd Edition. [source] In Focus: Pest Management and DarwinPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 11 2009Stephen O Duke No abstract is available for this article. [source] A comparison of management options for leatherjacket populations in organic crop rotations using mathematical modelsAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 2 2009Rod P. Blackshaw Abstract 1,Pest management in organic systems is challenged by the paucity of options for direct interventions to control damaging populations compared with conventional agriculture. Consequently, a greater emphasis has to be placed on managing pest numbers through a rotation. In the present study, simulation modelling is used to evaluate the effects of different management options on populations of Tipula paludosa (leatherjackets) in organic rotations. 2,The growth of leatherjacket populations in grass was simulated over 5 years for different starting numbers. A significant risk of leatherjacket attack to subsequent crops can be avoided by limiting the fertility building phase of a rotation to a maximum of 2 years. 3,The effect of cultural control through additional cultivation interventions was compared in rotations comprising a grass/clover fertility building phase with host and/or nonhost crops. It is concluded that the effects are marginal and that prophylactic use cannot be recommended. 4,The prophylactic use of biological control agents in permanent grass and grass/arable rotations was investigated. Maximum population reductions in grass were achieved through annual autumn applications but the optimal economic strategy was less frequent than this. Application in the autumn preceding a spring-sown arable crop provided the best risk reduction. 5,A model decision support system for the control of pests in organic systems using data for leatherjacket damage to spring barley is presented. Economic threshold concepts are used to define when cultural control (as additional cultivation) and biocontrol applications should be used. 6,The present study shows the potential benefits of simulation modelling for the rapid evaluation of a wide range of pest management options. Any conclusions drawn from such simulations, however, are provisional until they can be tested experimentally. [source] Predicting the unexpected: using a qualitative model of a New Zealand dryland ecosystem to anticipate pest management outcomesAUSTRAL ECOLOGY, Issue 4 2009DAVID S. L. RAMSEY Abstract Pest management is expensive and there is often uncertainty about the benefits for the resources being protected. There can also be unintended consequences for other parts of the ecosystem, especially in complex food webs. In making decisions managers generally have to rely on qualitative information collected in a piecemeal fashion. A method to assist decision making is a qualitative modelling approach using fuzzy cognitive maps, a directed graphical model related to neural networks that can take account of interactions between pests and conservation assets in complex food webs. Using all available information on relationships between native and exotic resources and consumers, we generated hypotheses about potential consequences of single-species and multi-species pest control on the long-term equilibrium abundances of other biotic components of an ecosystem. We applied the model to a dryland ecosystem in New Zealand because we had good information on its trophic structure, but the information on the strength of species interactions was imprecise. Our model suggested that pest control is unlikely to significantly boost native invertebrates and lizards in this ecosystem, suggesting that other forms of management may be required for these groups. Most of the pest control regimes tested resulted in greater abundances of at least one other pest species, which could potentially lead to other management problems. Some of the predictions were unexpected, such as more birds resulting from possum and mouse control. We also modelled the effects of an increase in invasive rabbits, which led to unexpected declines of stoats, weasels, mice and possums. These unexpected outcomes resulted from complex indirect pathways in the food web. Fuzzy cognitive maps allow rapid construction of prototype models of complex food webs using a wide range of data and expert opinion. Their utility lies in providing direction for future monitoring efforts and generating hypotheses that can be tested with field experiments. [source] Mortality dynamics and population regulation in Bemisia tabaciENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2005Steven E. Naranjo Abstract Natural mortality is an important determinant of the population dynamics of a species, and an understanding of mortality forces should aid in the development of better management strategies for insect pests. An in situ, observational method was used to construct cohort-based life tables for Bemisia tabaci (Gennadius) Biotype B (Homoptera: Aleyrodidae) over 14 generations on cotton in central Arizona, USA, from 1997 to 1999. In descending order, median marginal rates of mortality were highest for predation, dislodgment, unknown causes, egg inviability, and parasitism. The highest mortality occurred during the 4th nymphal stadium, and the median rate of immature survival over 14 generations was 6.6%. Predation during the 4th nymphal stadium was the primary key factor. Irreplaceable mortality was highest for predation and dislodgment, with the absence of these mortality factors leading to the greatest increases in estimated net reproduction. There was little evidence of direct or delayed density-dependence for any mortality factor. Wind, rainfall, and predator densities were associated with dislodgment, and rates of predation were related to densities of Geocoris spp., Orius tristicolor (White), Chrysoperla carnea s.l. Stephens, and Lygus hesperus Knight. Simulations suggest that immigration and emigration play important roles in site-specific dynamics by explaining departures from observed population trajectories based solely on endogenous reproduction and mortality. By a direct measurement of these mortality factors and indirect evidence of adult movement, we conclude that efficient pest management may be best accomplished by fostering greater mortality during the 4th stadium, largely through a conservation of predators and by managing immigrating adult populations at their sources. [source] Regulatory impact on insect biotechnology and pest managementENTOMOLOGICAL RESEARCH, Issue 4 2007Chris A. WOZNIAK Abstract The application of insect biotechnology is promising for the development of environmentally compatible pest management solutions. As we have refined and enhanced genetic engineering techniques in several insect species that cause significant economic loss and public health injury, it has become clear that insect biotechnology will move forward as one of the key tools of pest management in agriculture and in the human environment. Well characterized genetic elements can be manipulated toward specific aims and maintain a viable insect, albeit one with diminished capacity to exchange genetic material, vector a virus or bacterium, or complete its life cycle. Despite this degree of knowledge and precision, there remain unanswered questions regarding environmental fate, release and public acceptance of this technology. The uncertainty surrounding any novel technology inevitably increases the level of regulatory scrutiny associated with its use. Although the term "insect biotechnology" has many connotations, it certainly includes the genetic modification of symbiotic or commensally associated microbes as a means of delivering a trait (e.g. a toxin) to manage plant and human diseases and insect pests. The distinction between this paratransgenic approach and direct genetic modification of insect pests is an important one biologically as well as from a regulatory standpoint. The regulatory framework for microbial applications to agriculture is in many instances in place; however, we must strive to forge the development of guidelines and regulations that will foster deployment of insect biotechnologies. [source] Why pest management needs behavioral ecology and vice versaENTOMOLOGICAL RESEARCH, Issue 1 2007Bernard D. ROITBERG Abstract Behavior manipulation is becoming an accepted tactic in pest management, however, there are many ways in which the approach can be improved. In this review, I explain how and why insect behavioral response to various stimuli can vary dramatically under different conditions and that it is this variable response that must be understood before behavior manipulation becomes widely accepted in pest management programs. I propose that entomologists use concepts from behavioral ecology to manipulate pest behavior in a predictable manner. The key is to study behaviors that maximize fitness in natural environments and then exploit these behaviors in agriculture. I provide examples from a range of behavior manipulation tactics, including use of attracticides, kairomone-mediated biological control, use of marking pheromones, and push-pull manipulation. [source] Computer simulation of the population dynamics of Panonychus ulmi and applications to integrated pest management,EPPO BULLETIN, Issue 1 2000M. Sobala Panonychus ulmi is a serious pest of apple orchards, especially in hot dry years. To improve quantitative insight into its population dynamics, and as a tool for forecasting optimal dates for visual assessment of abundance and of integrated pest management strategies, an age- and stage-structured temperature-dependent predator,prey model for P. ulmi and two of its natural enemies, Typhlodromus pyri and Amblyseius potentillae, has been developed. [source] BROADENING THE APPLICATION OF EVOLUTIONARILY BASED GENETIC PEST MANAGEMENTEVOLUTION, Issue 2 2008Fred Gould Insect- and tick-vectored diseases such as malaria, dengue fever, and Lyme disease cause human suffering, and current approaches for prevention are not adequate. Invasive plants and animals such as Scotch broom, zebra mussels, and gypsy moths continue to cause environmental damage and economic losses in agriculture and forestry. Rodents transmit diseases and cause major pre- and postharvest losses, especially in less affluent countries. Each of these problems might benefit from the developing field of Genetic Pest Management that is conceptually based on principles of evolutionary biology. This article briefly describes the history of this field, new molecular tools in this field, and potential applications of those tools. There will be a need for evolutionary biologists to interact with researchers and practitioners in a variety of other fields to determine the most appropriate targets for genetic pest management, the most appropriate methods for specific targets, and the potential of natural selection to diminish the effectiveness of genetic pest management. In addition to producing environmentally sustainable pest management solutions, research efforts in this area could lead to new insights about the evolution of selfish genetic elements in natural systems and will provide students with the opportunity to develop a more sophisticated understanding of the role of evolutionary biology in solving societal problems. [source] A framework of knowledge versioning managementEXPERT SYSTEMS, Issue 3 2004M. T. Maliappis Abstract: Knowledge is an inherently dynamic entity continuously changing and evolving. In many cases, the coexistence of different versions of the same core knowledge is a necessity. So is the availability of the proper environment and tools to deal with knowledge versioning. In this paper, a framework of knowledge versioning management is proposed and implemented dealing with hybrid knowledge representation models using frames and rules. This framework facilitates knowledge version handling and maintenance, improving, in parallel, knowledge sharing and reuse. Knowledge components are stored in a set of tables and handled as data under the auspices of a database management system. The proper structure of tables and their relationships allows the creation of independent knowledge modules. Several knowledge modules can be assembled to construct higher level modules, which finally form versions of knowledge. Corresponding knowledge base versions consist of several knowledge modules easy to handle and process in various application areas. The proposed framework has been implemented and thoroughly examined in an application area of great importance, such as pest management. [source] Isolation of transcripts from Diabrotica virgifera virgifera LeConte responsive to the Bacillus thuringiensis toxin Cry3Bb1INSECT MOLECULAR BIOLOGY, Issue 3 2010A. Sayed Abstract Crystal (Cry) proteins derived from Bacillus thuringiensis (Bt) have been widely used as a method of insect pest management for several decades. In recent years, a transgenic corn expressing the Cry3Bb1 toxin has been successfully used for protection against corn rootworm larvae (genus Diabrotica). The biological action of the Bt toxin in corn rootworms has not yet been clearly defined. Because development of resistance to Bt by corn rootworms will have huge economic and ecological costs, insight into larval response to Bt toxin is highly desirable. We identified 19 unique transcripts that are differentially expressed in D. virgifera virgifera larvae reared on corn transgenic for Cry3Bb1. Putative identities of these genes were consistent with impacts on metabolism and development. Analysis of highly modulated transcripts resulted in the characterization of genes coding for a member of a cysteine-rich secretory protein family and a glutamine-rich membrane protein. A third gene that was isolated encodes a nondescript 132 amino acid protein while a fourth highly modulated transcript could not be further characterized. Expression patterns of these four genes were strikingly different between susceptible and resistant western corn rootworm populations. These genes may provide useful targets for monitoring of Bt exposure patterns and resistance development in pest and non-target insect populations. [source] Predicting abundance from occupancy: a test for an aggregated insect assemblageJOURNAL OF ANIMAL ECOLOGY, Issue 3 2003M. Warren Summary 1The ubiquitous, positive abundance-occupancy relationship is of potential value to conservation and pest management because of the possibility of using it to predict species abundance from occupancy measures. 2He & Gaston (2000a) developed a model, and a parameterization method, for the prediction of abundance from occupancy based on the negative binomial distribution. There are to date few empirical tests of either the estimation method or model. Here we conduct such a test in a field-based mesocosm experiment using a Drosophilidae assemblage associated with decaying fruit. 3With individual (and groups of) fruit as minimum mapping units, abundance estimates derived using the parameterization method of the He-Gaston model differed significantly from measured values, and were least accurate for the most abundant species. 4Substitution of k -values corrected for species density in the model did not improve abundance predictions significantly. However, substitution of k -values calculated directly from the negative binomial distribution yielded highly accurate abundance predictions. 5Although the distribution of fly species did not deviate significantly from the negative binomial distribution, and the finest possible minimum mapping units were used (individual fruit), the parameterization method in the He-Gaston model consistently underestimated the abundance of species in the assemblage because individuals were very highly aggregated within fruit. 6Because of its potential importance, this model and parameterization method require further exploration at fine scales, commonly represented by individual habitat units, for highly aggregated species. The incorporation of spatially explicit information may provide a means of improving abundance predictions in this regard. [source] Fallowing did not disrupt invertebrate fauna in Philippine low-pesticide irrigated rice fieldsJOURNAL OF APPLIED ECOLOGY, Issue 3 2010Kenneth G. Schoenly Summary 1.,Fallowing, a type of rotation where no crop is grown, deprives insect pests of food. In tropical irrigated rice, it is not known whether fallow periods deplete natural enemy populations and reduce their pest control effectiveness in post-fallow crops. We tested the null hypothesis that small-scale synchronous cropping (embedded in asynchronously planted rice landscapes) does not significantly increase pest densities during post-fallow periods in the presence of a large, diverse natural enemy complex undisrupted by insecticides. We tested this null hypothesis by comparing the invertebrate fauna before and after fallowing. 2.,In six molluscicide-only fields at the International Rice Research Institute (IRRI) in southern Luzon and at Zaragoza in central Luzon, Philippines, canopy and floodwater invertebrates were vacuum-sampled over two cropping seasons, dry and wet. 3.,Thirty-three of the ubiquitous common taxa dominated the samples in both seasons at each site. Most species were natural enemies of rice pests and recyclers of organic matter in the floodwater and waterlogged sediments; some were rice pests. 4.,Fallowing depleted populations of more ubiquitous taxa at Zaragoza (four natural enemies, one detritivore) than at IRRI (one herbivore, one natural enemy). At both sites, only green leafhoppers, Nephotettix virescens and Nephotettix nigropictus, had consistently higher post-fallow densities than pre-fallow densities. 5.,At both sites, fallowing did not affect rice-invertebrate faunas differently between seasons with regard to community structure, trajectories and accumulation rates of guild members. 6.,Synthesis and applications.,In tropical irrigated rice fields, small-scale synchronous fallowing combined with low-pesticide inputs and pest-resistant rice varieties did not induce pest outbreaks or notably diminish populations of natural enemies when embedded in asynchronous cropping on larger, regional scales. Our results suggest that small-scale synchronous fallowing, when embedded in asynchronously planted landscapes, does little harm to biological regulation of the invertebrate faunal community and may be adopted as part of integrated pest management when it serves other purposes. [source] Pests, pesticide use and alternative options in European maize production: current status and future prospectsJOURNAL OF APPLIED ENTOMOLOGY, Issue 5 2010M. Meissle Abstract Political efforts are made in the European Union (EU) to reduce pesticide use and to increase the implementation of integrated pest management (IPM). Within the EU project ENDURE, research priorities on pesticide reduction are defined. Using maize, one of the most important crops in Europe, as a case study, we identified the most serious weeds, arthropod pests, and fungal diseases as well as classes and amounts of pesticides applied. Data for 11 European maize growing regions were collected from databases, publications and expert estimates. Silage maize dominates in northern Europe and grain production in central and southern Europe. Crop rotations range from continuous growing of maize over several years to well-planned rotation systems. Weeds, arthropod pests and fungal diseases cause economic losses in most regions, even though differences exist between northern countries and central and southern Europe. Several weed and arthropod species cause increasing problems, illustrating that the goal of reducing chemical pesticide applications is challenging. Pesticides could potentially be reduced by the choice of varieties including genetically modified hybrids, cultural control including crop rotation, biological control, optimized application techniques for chemicals, and the development of more specific treatments. However, restrictions in the availability of alternative pest control measures, farm organization, and the training and knowledge of farmers need to be overcome before the adoption of environmentally friendly pest control strategies can reduce chemical pesticides in an economically competitive way. The complex of several problems that need to be tackled simultaneously and the link between different control measures demonstrates the need for IPM approaches, where pest control is seen in the context of the cropping system and on a regional scale. Multicriteria assessments and decision support systems combined with pest monitoring programs may help to develop region-specific and sustainable strategies that are harmonized within a EU framework. [source] Effect of eggplant transformed with oryzacystatin gene on Myzus persicae and Macrosiphum euphorbiaeJOURNAL OF APPLIED ENTOMOLOGY, Issue 2 2006A. P. O. Ribeiro Abstract:, The effect of a genetically modified eggplant line expressing oryzacystatin on Myzus persicae (Sulzer) and Macrosiphum euphorbiae (Thomas) was examined. The transgenic eggplant reduced the net reproductive rate (R0), the instantaneous rate of population increase (r), and the finite rate of population increase (,) of both aphids species compared with a control eggplant line. The mean generation time (T) of the aphids was unaffected by the transgenic plants. Age-specific mortality rates of M. persicae and M. euphorbiae were higher on transgenic plants. These results indicate that expression of oryzacystatin in eggplant has a negative impact on population growth and mortality rates of M. persicae and M. euphorbiae and could be a source of plant resistance for pest management of these aphids. [source] Resistance of the codling moth Cydia pomonella (L.) (Lep., Tortricidae) to pesticides in IsraelJOURNAL OF APPLIED ENTOMOLOGY, Issue 9-10 2004H. Reuveny Abstract:, Resistance of the codling moth Cydia pomonella (L.) (Lep., Tortricidae) to the organophosphorus compound (OP) azinphosmethyl was observed in apple orchards in Israel. The level of resistance varied with the pest control strategy. Compared with a sensitive laboratory population, the resistance level was highest in insects from the preventative pest control strategy, intermediate in integrated pest management (IPM) orchards, and relatively low in the organic orchards. The level of azinphosmethyl resistance in larvae (but not in adults) exposed for 17 generations in the laboratory to a pesticide-free diet was reduced by 50%. Codling moth larvae resistant to azinphosmethyl were also resistant to various insect growth regulators (IGRs). The IGRs include three chitin synthesis inhibitors (diflubenzuron, novaluron and teflubenzuron), two juvenile hormone mimics (pyriproxyfen and fenoxycarb) and one ecdysone agonist (methoxyfenozide). Codling moth resistant to azinphosmethyl was tolerant to methoxyfenozide and novaluron without previous history of application in apple orchards, indicating the possibility of cross-resistance. According to this study, managing resistance programs in apple orchards should be based on IPM principles with minimum use of conventional neuroactive pesticides. [source] Study of the relationship between sex pheromone trap catches of Lobesia botrana (Den. & Schiff.) (Lep., Tortricidae) and the accumulation of degree-days in Sherry vineyards (SW of Spain)JOURNAL OF APPLIED ENTOMOLOGY, Issue 1-2 2001R. Del Tío The relationship between temperature accumulations and pheromone trap captures of the males of Lobesia botrana (Den. & Schiff.) (Lep., Tortricidae) in the Sherry vineyards (SW of Spain) presents a statistically acceptable linear behaviour through conveniently transforming the variables. Data series ranging from 1990 to 1995 were used to compute the linear correlations. The reliability of the forecasts based on the resulting log-probit lines have shown to be acceptable in order to be considered as an useful tool to improve the effectiveness of the integrated pest management in the area. [source] Pheromone blends and trap designs can affect catches of Sesamia nonagrioides Lef. (Lep., Noctuidae) males in maize fieldsJOURNAL OF APPLIED ENTOMOLOGY, Issue 1-2 2001A. Ameline Among lepidopteran insects, the female-produced sex pheromones are the most widely used chemical stimuli for pest management by (i) mating disruption, and (ii) monitoring adult insect populations in agricultural crops. Sesamia nonagrioides is one of the main pests on maize crops around the Mediterranean area and monitoring adult populations with synthetic sex pheromone is of great interest. The technique used involved field trapping with synthetic pheromone blend. The reliability of the technique is directly related to the trap shape and pheromone blends. Universal Moth Trap® (UM trap, Biosyste,mes, France) and Service Régional de la Protection des Végétaux (SRPV) traps baited with either synthetic pheromone blend or virgin females were evaluated in two commercial maize fields (var.cecilia) (Belleserre, Tarn. France) to determine the potential use of synthetic lures in monitoring S. nonagrioides populations in maize field. The study showed that SRPV traps baited with synthetic pheromone blend caught significantly more S. nonagrioides males than UM traps baited with the same blend, indicating the efficiency of the SRPV traps in monitoring field population of S. nonagrioides. The study also showed that the synthetic pheromone-baited SRPV trap caught three times less adult males than the same traps baited with virgin females indicating that the synthetic blend was less attractive than the natural blend released by virgin females. However, despite the lower number of catches in the SRPV traps baited with synthetic pheromones, there was a significant and positive relationship between the number of catches in SRPV traps baited with the synthetic pheromone and with the females. This result indicates that synthetic pheromones can be used as baits in SRPV traps to monitor S. nonagrioides adult population in commercial maize crops. Nevertheless, to use the synthetic pheromone to monitor S. nonagrioides population effectively in the field, further refinement and improvement of the synthetic blend should be carried out in order to obtain a blend that is equally as attractive as the natural blend released by virgin females. [source] Laboratory and field studies on the integrated pest management of Helicoverpa armigera (Hübner) in cotton, based on pheromone trap catch threshold levelJOURNAL OF APPLIED ENTOMOLOGY, Issue 5-6 2000G. V. P. Reddy Results revealed that egg parasitism in the laboratory by Trichogramma chilonis was 75.6%. Among the insecticides tested against T. chilonis and the predator Chrysoperla carnea, nimbecidine (neem product) and dipel resulted in zero mortality, with only a low level of mortality by dimethoate, cypermethrin, fenvalerate, alphamethrin and monocrotophos. Combinations of nimbecidine 2% + NPV at 250 larval equivalents (LE)/ha and dipel 8 l + NPV @250 LE/ha were the most effective treatments against H. armigera. The integrated pest management components (T. chilonis, C. carnea, NPV, nimbecidine, dipel and synthetic chemicals) were imposed at different intervals on the basis of pheromone trap threshold level (7 moths/trap per night) on a consolidated block of 40 ha cotton (MCU-1) fields at two locations, Shankarabanda and Korlagundi. The results demonstrated a significant superiority of the IPM strategy in terms of both cost versus benefit and environmental safety over that used in the farmer's fields where only conventional control methods were followed. [source] Descriptive biogeography of Tomicus (Coleoptera: Scolytidae) species in SpainJOURNAL OF BIOGEOGRAPHY, Issue 12 2004D. Gallego Abstract Aim, location,Tomicus (Coleoptera, Scolytidae) species are some of the principal pests of Eurasian forest and are represented by three coexisting species in Spain, Tomicus piniperda (Linnaeus, 1758), Tomicus destruens (Wollaston, 1865) and Tomicus minor (Harting, 1834). The distribution of two taxa are unknown as they have until recently been considered separate species. Therefore, we model the potential distribution centres and establish the potential distribution limits of Tomicus species in Iberia. We also assess the effectiveness of different models by comparing predicted results with observed data. These results will have application in forest pest management. Methods, Molecular and morphological techniques were used to identify species from 254 specimens of 81 plots. For each plot, a Geographical Information System was used to extract a set of 14 environmental (one topographic, six climatic) and biotic variables (seven host tree distributions). General Additive Models and Ecological Niche Factor Analysis models are applied for modelling and predicting the potential distribution of the three especies of Tomicus. Results, The results of both modelling methodologies are in agreement. Tomicus destruens is the predominant species in Spain, living in low and hot areas. Tomicus piniperda occurs in lower frequency and prefers wet and cold areas of north-central Spain. We detected sympatric populations of T. destruens and T. piniperda in Northern coast of Spain, infesting mainly P. pinaster. Tomicus minor is the rarest species, and it occupies a fragmented distribution located in high and wet areas. The remarkable biotic variable is the distribution of P. sylvestris, incorporated into the models of T. destruens and T. piniperda. Main conclusions, These results indicate that in wet areas of north-central Spain where T. piniperda occurs (and possibly the high altitudes of the southern mountains), T. destruens has a climatic distribution limit. In the northern border of this area, both species overlap their distributions and some co-occurrences were detected. Tomicus minor potentially occurs in high and wet fragmented areas. [source] Host,parasitoid population density prediction using artificial neural networks: diamondback moth and its natural enemiesAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 3 2010Henri E. Z. Tonnang 1An integrated pest management (IPM) system incorporating the introduction and field release of Diadegma semiclausum (Hellén), a parasitoid of diamondback moth (DBM) Plutella xylostella (L.), comprising the worst insect pest of the cabbage family, has been developed in Kenya to replace the pesticides-only approach. 2Mathematical modelling using differential equations has been used in theoretical studies of host,parasitoid systems. Although, this method helps in gaining an understanding of the system's dynamics, it is generally less accurate when used for prediction. The artificial neural network (ANN) approach was therefore chosen to aid prediction. 3The ANN methodology was applied to predict the population density of the DBM and D. semiclausum, its larval parasitoid. Two data sets, each from different release areas in the Kenya highlands, and both collected during a 3-year period after the release of the parasitoid, were used in the present study. Two ANN models were developed using these data. 4The ANN approach gave satisfactory results for DBM and for D. semiclausum. Sensitivity analysis suggested that pest populations may be naturally controlled by rainfall. 5The ANN provides a powerful tool for predicting host,parasitoid population densities and made few assumptions on the field data. The approach allowed the use of data collected at any appropriate scale of the system, bypassing the assumptions and uncertainties that could have occurred when parameters are imported from other systems. The methodology can be explored with respect to the development of tools for monitoring and forecasting the population densities of a pest and its natural enemies. In addition, the model can be used to evaluate the relative effectiveness of the natural enemies and to investigate augmentative biological control strategies. [source] Spatio-temporal analysis of plant pests in a greenhouse using a Bayesian approachAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 3 2010Christine Poncet 1The present study aimed to propose a method that can improve our understanding of pest outbreaks and spatio-temporal development in greenhouse crops. 2The experiment was carried out in a greenhouse rose crop grown under integrated pest management (IPM) for 21 months. The main pests observed were powdery mildew, two-spotted spider mites and western flower thrips. A quick visual sampling method was established to provide continuous monitoring of overall crop health. 3A Bayesian inferential approach was then used to analyse temporal and spatial heterogeneity in the occurrence of pests. Interactions between pest dynamics and properties of spatial evolutions were exhibited revealing the influence of biotic and abiotic factors on crop health. 4In the context of IPM, this information could be used to improve monitoring strategies by identifying periods or locations at risk. It could also facilitate the implementation of the whole IPM procedure through the identification of key factors that have a negative impact on overall crop health. [source] Behaviour and ecology of the western corn rootworm (Diabrotica virgifera virgifera LeConte)AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 1 2009Joseph L. Spencer Abstract 1,The western corn rootworm (WCR) is a historic pest with a legacy of resistance and behavioural plasticity. Its behaviour and nutritional ecology are important to rootworm management. The success of the most effective and environmentally benign rootworm management method, annual crop rotation, was based on an understanding of rootworm behaviour and host,plant relationships. Enthusiastic adoption of crop rotation, provided excellent rootworm management, but also selected for behavioural resistance to this cultural control. 2,Though well-studied, significant gaps in WCR biology remain. Understanding the topics reviewed here (mating behaviour, nutritional ecology, larval and adult movement, oviposition, alternate host use, and chemical ecology) is a starting point for adapting integrated pest management and insect resistance management (IRM) to an expanding WCR threat. A presentation of significant questions and areas in need of further study follow each topic. 3,The expansion of WCR populations into Europe exposes this pest to new environmental and regulatory conditions that may influence its behaviour and ecology. Reviewing the state of current knowledge provides a starting point of reference for researchers and pest management decision-makers in North America and Europe. 4,The trend toward increasing adoption of transgenic maize will place an increasing premium on understanding WCR behaviour. IRM plans designed to promote sustainable deployment of transgenic hybrids are grounded on assumptions about WCR movement, mating and ovipositional behaviour. Preserving the utility of new and old management options will continue to depend on a thorough understanding of WCR biology, even as the ecological circumstances and geography of WCR problems become more complex. [source] Trichomes of Lycopersicon species and their hybrids: effects on pests and natural enemiesAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 1 2006Aaron T. Simmons Abstract 1,The cultivated tomato, Lycopersicon esculentum, is an economically important worldwide crop. Current pest management techniques rely heavily on pesticides but trichome-based host-plant resistance may reduce pesticide use. 2,A review of the literature is provided on trichomes of wild Lycopersicon species and the effects of trichome-based host-plant resistance on arthropods. Solvents have been used to remove glandular trichome exudates and the resulting dimminution of their effects quantified. Correlational approaches to assess the relationship between the different trichome types and effects on pests have also been used. 3,Most studies have focused on Lepidoptera and Hemiptera, although some work has included Coleoptera, Diptera and Acarina, and both antibiotic and antixenotic effects have been demonstrated. 4,Natural enemies are a cornerstone of international pest management and this review discusses how the compatibility of this approach with trichome-based host-plant resistance is uncertain because of the reported negative effects of trichomes on one dipteran, one hemipteran and several Hymenoptera. 5,For trichome-based host-plant resistance to be utilized as a pest management tool, trichomes of wild species need to be introgressed into the cultivated tomato. Hybrids between the cultivated tomato and the wild species Lycopersicon hirsutum f. glabratum, Lycopersicon pennellii and Lycopersicon cheesmanii f. minor have been produced and useful levels of resistance to Acarina, Diptera and Hemiptera pests have been exhibited, although these effects may be tempered by effects on natural enemies. 6,This review proposes that studies on genetic links between fruit quality and resistance, field studies to determine the compatibility of natural enemies and trichome-based host-plant resistance, and a strong focus on L. cheesmanii f. minor, are all priorities for further research that will help realize the potential of this natural defence mechanism in pest management. [source] Potential of a synthetic aggregation pheromone for integrated pest management of Colorado potato beetleAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 1 2006T. P. Kuhar Abstract 1The relative number of colonizing adult Colorado potato beetles (CPB) Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) coming to pitfall traps baited with the aggregation pheromone (S)-3,7-dimethyl-2-oxo-oct-6-ene-1,3-diol [(S)-CPB I] and the use of the pheromone in a trap crop pest management strategy were evaluated in the field for the first time. 2More than five-fold more adult L. decemlineata were caught in pitfall traps baited with the pheromone compared with controls. However, attraction to the pheromone diminished after 5 days in the field. 3In the trap crop management strategy, more colonizing adults were present in pheromone-treated rows of potatoes compared with untreated middle rows. 4Significantly fewer L. decemlineata egg masses and larvae were found in potato plots that were bordered by pheromone-treated rows, or bordered by imidacloprid + pheromone-treated rows, or rows treated at-planting with imidacloprid compared with untreated (control) potato plots. 5Densities of L. decemlineata egg masses and larvae and percentage defoliation were significantly lower, and marketable tuber yield significantly higher, in conventional imidacloprid-treated potatoes compared with all other treatments. 6Although our results demonstrate the potential for use of the aggregation pheromone in the management of L. decemlineata in the field, more research is needed to optimize the release rates of the attractant and incorporate control methods for cohabiting pests. [source] Effect of varying monoterpene concentrations on the response of Ips pini (Coleoptera: Scolytidae) to its aggregation pheromone: implications for pest management and ecology of bark beetlesAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 4 2003Nadir Erbilgin Abstract 1,Host plant terpenes can influence attraction of conifer bark beetles to their aggregation pheromones: both synergistic and inhibitory compounds have been reported. However, we know little about how varying concentrations of individual monoterpenes affect responses. 2,We tested a gradient of ratios of ,-pinene, the predominant monoterpene in host pines in the Great Lakes region of North America, to Ips pini's pheromone, racemic ipsdienol plus lanierone. 3,Ips pini demonstrated a parabolic response, in which low concentrations of ,-pinene had no effect on attraction to its pheromone, intermediate concentrations were synergistic and high concentrations were inhibitory. These results suggest optimal release rates for population monitoring and suppression programmes. 4,Inhibition of bark beetle attraction to pheromones may be an important component of conifer defences. At terpene to pheromone ratios emulating emissions from trees actively responding to a first attack, arrival of flying beetles was low. This may constitute an additional defensive role of terpenes, which are also toxic to bark beetles at high concentrations. 5,Reduced attraction to a low ratio of ,-pinene to pheromone, as occurs when colonization densities become high and the tree's resin is largely depleted, might reflect a mechanism for preventing excessive crowding. 6,Thanasimus dubius, the predominant predator of I. pini, was also attracted to ipsdienol plus lanierone, but its response differed from that of its prey. Attraction increased across all concentrations of ,-pinene. This indicates that separate lures are needed to sample both predators and bark beetles effectively. It also provides an opportunity for maximizing pest removal while reducing adverse effects on beneficial species. This disparity further illustrates the complexity confronting natural enemies that track chemical signals to locate herbivores. [source] Agricultural diversification and integrated pest management in BangladeshAGRICULTURAL ECONOMICS, Issue 3 2004Chowdhury Mahmoud IPM; Bangladesh; Vegetable production; Off-farm employment Abstract We study factors associated with a shift toward diversified, high-valued vegetable crops and the incentives associated with the use of IPM methods for vegetable producers in Bangladesh. The primary objective is to measure how IPM technologies affect the crop and technology choices of low-income rice farmers. A three-season household optimisation model is used to study crop and technology choice under price and yield uncertainty. The model is parameterised using data from vegetable farms and experimental IPM trials conducted in Bangladesh. Simulation results show that access to IPM technology and IPM availability combined with access to credit increase household welfare and lead to higher rates of vegetable adoption. Off-farm employment opportunities work against vegetable cultivation and IPM use by risk-averse farmers. Implications for policy and extension efforts are highlighted. [source] Chemical genetics: catalysing pathway exploration and new target discoveryJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2007Joshua I Armstrong Abstract Chemical genetics couples the availability of diverse chemistry with the strengths of molecular genetics to dissect signalling pathways in complex organisms. Plant biology laboratories have integrated this approach into their repertoire for probing hormone signalling, physiology and pesticide mode of action. These studies have led to the discovery of compounds that regulate development and the response to environmental stress. Chemical genetics facilitates our understanding of genetic signalling pathways and offers a new approach to pest management and plant health by enabling the direct chemical modulation of plant defence signalling. Copyright © 2007 Society of Chemical Industry [source] Inorganic phosphate has a crucial effect on Cry3Aa , -endotoxin productionLETTERS IN APPLIED MICROBIOLOGY, Issue 4 2005A. Kurt Abstract Aims:, The study aimed at increasing Cry3Aa , -endotoxin production by a local isolate of Bacillus thuringiensis (B.t. strain Mm2). To this end, different nutritional conditions were tested for their effects on Cry3Aa yields. Methods and Results:,Bacillus thuringiensis Mm2 was grown by shaking at 30°C in different media. Samples were taken from the cultures at intervals and used for protein extraction. SDS-PAGE was performed for toxin analysis. Inclusion of inorganic phosphate (Pi) into the Difco's sporulation medium at an increased level of 200 mmol l,1 caused a fivefold increase (from 3 to 15·6 ,g ml,1) in toxin production. Omission of FeSO4 from the medium decreased this yield by half. Resuspension experiments suggested catabolite repression of toxin biosynthesis by glucose. The inclusion of high Pi invariably increased toxin synthesis, even in the absence of sugars. Conclusions:, Inorganic phosphate had the most striking effect on toxin biosynthesis. Iron effect was found to be unique to our isolate whereas Pi effect seemed to be common to the biosynthesis of Cry3Aa-type toxins. Stimulation of toxin synthesis by Pi did not seem to represent a relief from glucose repression. Significance and Impact of the Study:,Bacillus thuringiensis is the most versatile biopesticide for use in pest management. Regarding cost-effectiveness of related fermentations, high Pi supplement drastically increases Coleoptera-specific toxin synthesis. [source] | |||||||||||||||||||||||||||||||