scholarly journals Pests, pathogens, pathogenic diseases, and diseases control strategies of sal (Shorea robusta) in Nepal

2021 ◽  
Vol 6 (2) ◽  
pp. 210-217
Author(s):  
Vivek Thapa Chhetri ◽  
Resham G.C. ◽  
Sanup Chaudhary ◽  
Sachin Timilsina ◽  
Subash Gautam

Sal (Shorea robusta) is one of the most indispensable species in Nepal, both ecologically and economically. This paper aims to provide updated guidance for the management and protection of this species in the future from various pests and pathogens. We reviewed 38 articles from Google Scholar and Research gate with keywords "Shorea robusta”, “Hoplocerambyx spinicornis”, “Polyporus shoreae”, “Heart rot”. S. robusta has the most insect fauna among the forest tree species. Out of the 346 insects reported on S. robusta, around 155 species of insects are associated with living trees. Hoplocerambyx spinicornis is the most destructive insect pest, wreaking havoc on S. robusta. Polyporous shoreae is the main cause of root rot in S. robusta, and spreads through root contact or root grafting. Heart rot in S. robusta is caused by the fungi Hymenochaete rubiginosa, Fomes caryophylli, and F. fastuosus. During the harvesting of S. robusta, the majority of the tree was observed to be faulty, resulting in a large amount of waste wood. The best way to determine the pathogen's "Achilles' heel" is to consider its life cycle. The Nepalese famous saying "prevention is better than cure" may be applicable in the management of S. robusta insect pests and pathogens. The current paper critically addresses these issues and argues the need for an improvised package of activities for insect pests, pathogens, prevention, and their control.

2015 ◽  
Vol 38 (4) ◽  
pp. 313-322
Author(s):  
N. Roychoudhury

Shorea robusta Gaertn. f. (Dipterocarpaceae), commonly known as sal, is one of the most important timbers of India both ecologically and economically. It is of Indian origin, widely distributed in central and north India and constitutes an important ecosystem, which provides cool and calm environment rich in biodiversity. This tree species has a highest number of insect fauna among the forest trees. Of about 346 insects recorded on sal, about 155 species of insects belonging to the order Lepidoptera (105), Coleoptera (31), Thysanoptera (9), Hemiptera (4), Orthoptera (4), Ephemeroptera (1) and Isoptera (1) are associated with living tree. The major insect pests of sal are, ‘seed and seedling borer’ Pammene theristis Meyrick (Lepidoptera: Eucosmidae), feeding on seed while they are on the tree; Sitophilus rugicollis Casey (Coleoptera : Curculionidae), damage seed either on the forest floor or during storage; white grubs such as Holotrichia spp. (Coleoptera : Scarabaeidae), which feed on the root system of the plants in nurseries and beetles feed on the foliage; defoliators such as Caviria sericea Moore (Lepidoptera : Lymantriidae), Lymantria mathura Moore (Lepidoptera : Lymantriidae), Paectes subapicalis Walker (Lepidoptera : Noctuidae), Trabala vishnou Lefebvre (Lepidoptera : Lasiocampidae), which feed on the leaves; stem borer such as Hoplocerambyx spinicornis Newman (Coleoptera : Cerambycidae) and sap sucker, such as Drosicha stebbingi Green (Hemiptera : Coccidae). Termites, such as Coptotermes curvignathus Holmgren (Isoptera : Rhinotermitidae) and timber borers, such as Sinoxylon anale and S. crassum (Coleoptera : Bostrychidae), damage sal timber in dying, felled or stored logs in depots.


2014 ◽  
Vol 54 (3) ◽  
pp. 205-210 ◽  
Author(s):  
David William Hagstrum ◽  
Paul Whitney Flinn

Abstract Stored-product entomologists have a variety of new monitoring, decision-making, biological, chemical, and physical pest management tools available to them. Two types of stored-product insect populations are of interest: insects of immediate economic importance infesting commodities, and insects that live in food residues in equipment and facilities. The sampling and control methods change as grain and grain products move from field to consumer. There are also some changes in the major insect pest species to take into consideration. In this review, we list the primary insect pests at each point of the marketing system, and indicate which sampling methods and control strategies are most appropriate. Economic thresholds for insect infestation levels developed for raw commodity storage, processing plants, and retail business allow sampling-based pest management to be done before insect infestations cause economic injury. Taking enough samples to have a representative sample (20-30 samples) will generally provide enough information to classify a population as above or below an economic threshold.


2014 ◽  
Vol 25 ◽  
pp. 18-28 ◽  
Author(s):  
Oladele Abiodun Olaniran ◽  
Samuel Adelani Babarinde ◽  
Adeola Foluke Odewole ◽  
Peter Ademola Aremu ◽  
Kehinde Popoola

Surveys were carried out in five local government areas of Ogbomoso Agricultural Zone Nigeria during planting season in 2010 to investigate rural farmers perceptions and management practices of insect pests of fruit vegetables. The survey involved 150 randomly selected farmers who were interviewed using structured questionnaire. Fruit vegetables planted by the farmers were okra, tomatoes, pepper and garden egg. Reasons given by farmers for cultivating fruit vegetables were significantly favored by age category, educational qualification, and secondary occupation of farmers (x2 = 4.757, P = 0.029). Field insect pests were perceived as the major production constraint to fruit vegetables in this zone. Majority of the farmer estimated 78.4 % rated insect pest as the most serious pest infesting fruit vegetables, the insect pests were grasshopper (Orthoptera), beetles (Coleoptera) and caterpillar (Lepidoptera). Integrated pest management module consisted basically of chemical and cultural control strategies, with weeding, shifting cultivation and crop rotation as main cultural control methods. More than 76.7 % of the farmers make use of cultural control because of unavailability and cost of chemical insecticides. Only 23.3 % had access to chemical insecticides in controlling insect pest of fruit vegetables.


2016 ◽  
Author(s):  
Julie C. Blackwood ◽  
Roger Vargas ◽  
Xavier Fauvergue

SummaryThe management of insect pests has long been dominated by the use of chemical insecticides, with the aim of instantaneously killing enough individuals to limit their damage. To minimize unwanted consequences, environmentally-friendly approaches have been proposed that utilize biological control and take advantage of intrinsic demographic processes to reduce pest populations.We address the feasibility of a novel pest management strategy based on the release of insects infected with Wolbachia, which causes cytoplasmic incompatibilities in its host population, into a population with a pre-existing Allee effect. We hypothesize that the transient decline in population size caused by a successful invasion of Wolbachia can bring the population below its Allee threshold and, consequently, trigger extinction.We develop a stochastic population model that accounts for Wolbachia-induced cytoplasmic incompatibilities in addition to an Allee effect arising from mating failures at low population densities. Using our model, we identify conditions under which cytoplasmic incompatibilities and Allee effects successfully interact to drive insect pest populations toward extinction. Based on our results, we delineate control strategies based on introductions of Wolbachia-infected insects.We extend this analysis to evaluate control strategies that implement successive introductions of two incompatible Wolbachia strains. Additionally, we consider methods that combine Wolbachia invasion with mating disruption tactics to enhance the pre-existing Allee effect.We demonstrate that Wolbachia-induced cytoplasmic incompatibility and the Allee effect act independently from one another: the Allee effect does not modify the Wolbachia-invasion threshold, and cytoplasmic incompatibilities only have a marginal effect on the Allee threshold. However, the interaction of these two processes can drive even large populations to extinction. The success of this method can be amplified by the introduction of multiple Wolbachia cytotypes as well as the addition of mating disruption.Our study extends the existing literature by proposing the use of Wolbachia introductions to capitalize on pre-existing Allee effects and consequently eradicate insect pests. More generally, it highlights the importance of transient dynamics, and the relevance of manipulating a cascade of destabilizatons for pest management.


2020 ◽  
Vol 115 (1) ◽  
pp. 133
Author(s):  
Emmanuel Tochukwu NNEJI ◽  
Robert O. UDDIN II ◽  
Abdulrasak K. MUSA

<p>A field study was carried out to assess the efficacy of some botanicals in the control of field insect pests in two varieties of okra. Dry leaf extract of <em>Chromolaena odorata</em> (Siam weed) and fresh and dry root extracts of <em>Boerhavia diffusa</em> served as treatments which were compared with Lambda-cyhalothrin and a control. The experiment was fitted into a randomized complete block design with three replications. Data collected were subjected to Spearman’s correlation analysis and a two-way analysis of variance and significant different means were separated using Fishers Least Significant Difference (LSD) test at 5 % level of probability. The results revealed that treated plants generally performed better than the untreated plants as they were taller, had more leaves, branches, wider stem girths and gave higher fruit yield. Fresh root extract of <em>B. diffusa</em> performed better in most parameters measured. A significant positive correlation was observed between insect pest populations, and between growth and yield parameters, while there was a significant negative correlation between overall yield and insect pest population. NHAe 47-4 okra variety performed better than F1-Lucky variety. Fresh root extract of <em>B. diffusa</em> is recommended for management of <em>B. tabaci </em>(Genadius, 1889)<em> </em>and <em>Amrasca biguttula </em>Ishida, 1912<em> </em>in okra.</p>


2020 ◽  
Vol 31 (1) ◽  
pp. 24-35 ◽  
Author(s):  
Somiahnadar Rajendran

Insects are a common problem in stored produce. The author describes the extent of the problem and approaches to countering it. Stored products of agricultural and animal origin, whether edible or non-edible, are favourite food for insect pests. Durable agricultural produce comprising dry raw and processed commodities and perishables (fresh produce) are vulnerable to insect pests at various stages from production till end-use. Similarly, different animal products and museum objects are infested mainly by dermestids. Insect pests proliferate due to favourable storage conditions, temperature and humidity and availability of food in abundance. In addition to their presence in food commodities, insects occur in storages (warehouses, silos) and processing facilities (flour mills, feed mills). Insect infestation is also a serious issue in processed products and packed commodities. The extent of loss in stored products due to insects varies between countries depending on favourable climatic conditions, and pest control measures adopted. In stored food commodities, insect infestation causes loss in quantity, changes in nutritional quality, altered chemical composition, off-odours, changes in end-use products, dissemination of toxigenic microorganisms and associated health implications. The insects contribute to contaminants such as silk threads, body fragments, hastisetae, excreta and chemical secretions. Insect activity in stored products increases the moisture content favouring the growth of moulds that produce mycotoxins (e.g., aflatoxin in stored peanuts). Hide beetle, Dermestes maculatus infesting silkworm cocoons has been reported to act as a carrier of microsporidian parasite Nosema bombycis that causes pebrine disease in silkworms. In dried fish, insect infestation leads to higher bacterial count and uric acid levels. Insects cause damage in hides and skins affecting their subsequent use for making leather products. The trend in stored product insect pest management is skewing in favour of pest prevention, monitoring, housekeeping and finally control. Hermetic storage system can be supplemented with CO2 or phosphine application to achieve quicker results. Pest detection and monitoring has gained significance as an important tool in insect pest management. Pheromone traps originally intended for detection of infestations have been advanced as a mating disruption device ensuing pest suppression in storage premises and processing facilities; pheromones also have to undergo registration protocols similar to conventional insecticides in some countries. Control measures involve reduced chemical pesticide use and more non-chemical inputs such as heat, cold/freezing and desiccants. Furthermore, there is an expanding organic market where physical and biological agents play a key role. The management options for insect control depend on the necessity or severity of pest incidence. Generally, nonchemical treatments, except heat, require more treatment time or investment in expensive equipment or fail to achieve 100% insect mortality. Despite insect resistance, environmental issues and residue problems, chemical control is inevitable and continues to be the most effective and rapid control method. There are limited options with respect to alternative fumigants and the alternatives have constraints as regards environmental and health concerns, cost, and other logistics. For fumigation of fresh agricultural produce, new formulations of ethyl formate and phosphine are commercially applied replacing methyl bromide. Resistance management is now another component of stored product pest management. In recent times, fumigation techniques have improved taking into consideration possible insect resistance. Insect control deploying nanoparticles, alone or as carriers for other control agents, is an emerging area with promising results. As there is no single compound with all the desired qualities, a necessity has arisen to adopt multiple approaches. Cocktail applications or combination treatments (IGRs plus organophosphorus insecticides, diatomaceous earth plus contact insecticides, nanoparticles plus insecticides/pathogens/phytocompounds and conventional fumigants plus CO2; vacuum plus fumigant) have been proved to be more effective. The future of store product insect pest management is deployment of multiple approaches and/or combination treatments to achieve the goal quickly and effectively.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
B. Naseri ◽  
M. Gheitury ◽  
M. Veisi

SummaryUnderstanding pathogen-agrosystem interaction is particularly essential when applying a control method to minimize pathogen prevalence prior to plant infection. To meet this requirement, frequency of major root rot pathogens isolated from bean root and seed, and their soil populations were examined in farmers’ fields. Multivariate analyses evidenced more frequent isolations of Fusarium solani and Rhizoctonia solani from root and seed compared to Macrophomina phaseolina and Fusarium oxysporum. Two Fusarium species had denser soil populations than R. solani and M. phaseolina. More frequent isolations of pathogens were detected in root and seed collected from Abhar and Khodabandeh compared to Kheirabad region. Agronomic and soil variables corresponded less closely to root infections compared to soil infestation and seed infections. Bean market class, herbicide application, and planting depth were linked to root, seed and soil infestations. Such information provides a basis for increased confidence in choosing appropriate control strategies for a pathogen and region in sustainable agriculture.


1991 ◽  
Vol 56 ◽  
Author(s):  
B. Meuleman

After  its introduction at the start of this century, the Corsican pine has become  an important forest tree in Flanders (Belgium). The total area covered by  Corsican pine is about 11.000 ha. Due to climatological factors it is  virtually absent from the Walloon part of Belgium. Despite the crisis in 1984  - 1986, practical experiences with its vitality and disease resistance are  generally positive. Compared to Scots pine which is native to Belgium, its  productivity and insensitivity for insect pests is large.     To quantify the productivity of Corsican pine, a growth table was  constructed using a method developed by PALM and DAGNELIE. It was based on  data from 321 temporarily and 80 permanent plots distributed over Flanders.  Five yield classes were distinguished according to dominant height at 50  years. For each yield class, a series of tables as a function of treatment  was constructed. Treatments were characterized by the mean annual  circumference increment.     These tables allow to predict the growth of Corsican pines. Such  predictions for the whole range of species are necessary for the development  of a good forestry policy and for timber industries. The tables also provide  information for any given Corsican pine stand that is helpful in practice:  expected productivity, stand density, determination of the felling quantum.      The data show that the productivity of Corsican pine is very high. The very  early culmination of the current annual volume increment and the rather  constant level of the mean annual volume increment after culmination are  interesting new findings. It is also shown that it is possible to work with  long rotation periods. This offers good opportunities for the production of  high quality wood and is also important for the social and ecological role of  the forest.     Productivity is lowest on very dry and sandy soils. A high productivity on  moderately dry sand and loamy sand soils and loamy soils make the Corsican  pine one of the most valuable tree species for the Kempen in Flanders.  Although productivity is very high on well drained sandy loam and loam soils,  plantation of Corsican pine on these locations is not advised.


Author(s):  
Sandra A. Allan

Manipulation of insect behavior can provide the foundation for effective strategies for control of insect crop pests. A detailed understanding of life cycles and the behavioral repertoires of insect pests is essential for development of this approach. A variety of strategies have been developed based on behavioral manipulation and include mass trapping, attract-and-kill, auto-dissemination, mating and host plant location disruption, and push-pull. Insight into application of these strategies for insect pests within Diptera, Lepidoptera, Coleoptera, and Hemiptera/Thysanoptera are provided, but first with an overview of economic damage and traditional control approaches, and overview of relevant behavioral/ecological traits. Then examples are provided of how these different control strategies are applied for each taxonomic group. The future of these approaches in the context of altered crop development for repellency or as anti-feedants, the effects of climate change and the risks of behaviorally-based methods are discussed.


1977 ◽  
Vol 9 (1) ◽  
pp. 129-135 ◽  
Author(s):  
C. Robert Taylor ◽  
Ronald D. Lacewell

Throughout the southern states and at the federal level, much attention is being focused on the appropriate strategy for controlling cotton insect pests, particularly the boll weevil. This paper presents estimated economic impacts to farmers, regions and consumers of implementing three alternative boll weevil control strategies. One strategy evaluated is a proposed boll weevil eradication program which involves integrating many controls including insecticides, reproduction-diapause control by early season stalk destruction, pheromone-baited traps, trap crops, early season control with insecticide, and massive releases of sterile boll weevils. The plan is to eradicate the boll weevil in the U.S., and then indefinitely maintain a barrier at the U.S.-Mexico border to prevent future weevil immigration to the U.S.


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