scholarly journals Effects of Prohydrojasmon on the Number of Infesting Herbivores and Biomass of Field-Grown Japanese Radish Plants

2021 ◽  
Vol 12 ◽  
Author(s):  
Kengo Yoshida ◽  
Masayoshi Uefune ◽  
Rika Ozawa ◽  
Hiroshi Abe ◽  
Yuka Okemoto ◽  
...  

Prohydrojasmon (PDJ), an analog of jasmonic acid (JA), was found to induce direct and indirect defenses against herbivores in non-infested plants. To test whether PDJ can be used for pest control in crop production, we conducted experiments in pesticide-free Japanese radish fields from October 4 to December 12 in 2015. Twenty-four Japanese radish plants in three plots were treated with a 100 times-diluted commercial formulation (5%) of PDJ (treated plants), and 24 plants in three different plots were treated with water (control plants) until November 29 every week. Throughout the observation period, the number of aphids, leaf-mining fly larvae, vegetable weevils, and thrips was significantly lower on the treated plants than on the control plants. In contrast, the number of lepidopteran larvae was not significantly different between the treated and control plants throughout the study period. Parasitized aphids (mummies) were also observed in both plots. Poisson regression analyses showed that a significantly higher number of mummies was recorded on the treated plants as compared to that on the control plants when the number of aphids increased. This suggested that PDJ application to Japanese radish plants attracted more parasitoid wasps on the treated plants than on the control plants. We also identified eight terpenoids and methyl salicylate as the PDJ-induced plant volatiles in the headspace of the treated plants. Some of these volatiles might be responsible for attracting aphid-parasitoid wasps in the field. However, for other insect pests, we did not find any natural enemies. Interestingly, the genes of the JA and salicylic acid signaling pathways were differentially upregulated in the treated plants. We also observed that the PDJ treatments induced the expression of the genes related to glucosinolate biosynthesis and the subsequent isothiocyanate formation. Additionally, the weights of both the aboveground and belowground parts of the treated plants were significantly lower than those of the respective parts of the control plants. These results indicated that the treatment of Japanese radish plants with a 100 times-diluted commercial formulation of PDJ induced their direct and indirect defenses against several insect pest species to reduce their numbers, and negatively affected their biomass.

2021 ◽  
Vol 25 (1) ◽  
pp. 1-22
Author(s):  
MP Ali ◽  
B Nessa ◽  
MT Khatun ◽  
MU Salam ◽  
MS Kabir

The damage caused by insect pest is the continual factor for the reduction of rice production. To date, 232 rice insect pest species are identified in Bangladesh and more than 100 species of insects are considered pests in rice production systems globally, but only about 20 - 33 species can cause significant economic loss. The major goal of this study is to explore all the possible ways of developed and proposed technologies for rice insect pests management and minimize economic losses. Insect pests cause 20% average yield loss in Asia where more than 90% of the world's rice is produced. In Bangladesh, outbreak of several insects such as rice hispa, leafroller, gallmidge, stem borers and brown planthopper (BPH) occurs as severe forms. Based on previous reports, yield loss can reach upto 62% in an outbreak situation due to hispa infestation. However, BPH can cause 44% yield loss in severe infestested field. To overcome the outbreaks in odd years and to keep the loss upto 5%, it is necessary to take some preventive measures such as planting of resistant or tolerant variety, stop insecticide spraying at early establishment of rice, establish early warning and forecasting system, avoid cultivation of susceptible variety and following crop rotation. Subsequent quick management options such as insecticidal treatment for specific insect pest should also be broadcasted through variety of information systems. Advanced genomic tool can be used to develop genetically modified insect and plants for sustainable pest management. In addition, to stipulate farmers not use insecticides at early crop stgae and minimize general annualized loss, some interventions including training rice farmers, regular field monitoring, digitalization in correct insect pests identification and their management (example; BRRI rice doctor mobile app), and demonstration in farmers field. Each technology itself solely or combination of two or more or all the packages can combat the insect pests, save natural enemies, harvest expected yield and contribute to safe food production in Bangladesh. Bangladesh Rice J. 25 (1) : 1-22, 2021


1996 ◽  
Vol 14 (1) ◽  
pp. 22-26 ◽  
Author(s):  
D. Casey Sclar ◽  
Whitney S. Cranshaw

Abstract Use of systemic insecticides that can be injected either into the root system or trunk of woody plants provides several potential advantages, notably in control of drift during application. Recently, new classes of insecticides with systemic activity have been developed, which may supplant the organophosphate and carbamate systemic insecticides that have previously been available. To evaluate their potential to control insects affecting shade trees, studies were conducted using imidacloprid and abamectin on elm. Soil injections of imidacloprid appeared particularly effective, controlling all three of the target pest species in this study (elm leaf beetle, European elm scale, elm leaf aphid). Both imidacloprid and abamectin also were effective against at least some elm insects when injected into trunks. Persistence of irnidacloprid was unusually long, providing second season control of all elm insect pests, although root uptake following soil injections was slow.


2020 ◽  
Vol 16 (2) ◽  
pp. 13-23
Author(s):  
B.O. Bobadoye ◽  
A.O. Bobadoye

Understanding the biosecurity risks that invasive alien insect pest species currently ravaging forest trees pose is of great importance to forest ecosystems and health. This problem has posed significant challenges to researchers, relevant stakeholders, policy makers and national biosecurity agencies worldwide. This study gives an overview of the top 15 suspected insect pest species most likely to invade or have already invaded forested habitats in order to disrupt ecosystem services and biodiversity within the borders of Nigeria through borderline states (Gombe, Jigawa, Borno, Yobe, Sokoto, Cross River and Lagos). For Nigeria as a whole, all of these top 15 pest species have already established, with identified intra- border line states having no significant effect on severity of invasions ( F1,6=0.07, P=0.910) when compared to identified inter-border line states. This study concludes that the immediate biosecurity risks from already identified invasive insect pests are greater from outside country (inter) borders of Nigeria than within state-to-state (intra) borders of Nigeria. Our findings have potentially significant implications for immediate implementation of national biosecurity forest policy Acts in compliance with Cartagena and Nagoya protocols, emphasizing the need to initiate and implement biosecurity measures simultaneously with any ongoing trans-national border interventions. Keywords: Biosecurity, invasive alien pest species, forests, Nigeria


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.


2021 ◽  
Author(s):  
Aqeel Alyousuf ◽  
Dawood Hamid ◽  
Mohsen A. Desher ◽  
Amin Nikpay ◽  
Henk-Marten Laane

Abstract Tomato (Solanum lycopersicum L) is an important vegetable crop in Iraq. This horticultural crop is attacked by several insect pest species. Among them, the whitefly Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) and the tomato leaf miner Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) are the major threat of greenhouse tomatoes in Basrah province in south Iraq. The management of these pests is heavily based on application of chemical pesticides. Vast application of pesticides caused harmful damage to the environment, human health and may increasing the risk of pest resistance on insect populations. One of the promising strategies which are compatible with organic farming is application of silicon for enhancing plant vigor and resistance to pest damage on various agricultural crops. Due to these facts, the experiments have been carried out at Basrah University to evaluate the effects of silicon (Si) fertilization on tomato plants for reducing damage of these two major pests. Treatments comprised two type of Si applications (Soil drench treatment and foliar spraying) with four Si concentrations (0, 0.5, 1 and 2%) of AB Yellow ® silicic acid formulation. The population density of B. tabaci and T. absoluta were studied weekly during the growth season. The results clearly demonstrated that Silicon applications significantly decreased the population of immature of both whiteflies and tomato leaf miner on tomato crop in the greenhouse; Si-Foliar spraying was more effective in reducing the population density of these key pests compared to Si- soil drench application.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
José M. Herrera ◽  
Bruno Silva ◽  
Gerardo Jiménez-Navarro ◽  
Silvia Barreiro ◽  
Nereida Melguizo-Ruiz ◽  
...  

AbstractPest control services provided by naturally occurring species (the so-called biocontrol services) are widely recognized to provide key incentives for biodiversity conservation. This is particularly relevant for vertebrate-mediated biocontrol services as many vertebrate species are of conservation concern, with most of their decline associated to landscape modification for agricultural purposes. Yet, we still lack rigorous approaches evaluating landscape-level correlates of biocontrol potential by vertebrates over broad spatial extents to better inform land-use and management decisions. We performed a spatially-explicit interaction-based assessment of potential biocontrol services in Portugal, using 1853 pairwise trophic interactions between 78 flying vertebrate species (birds and bats) and 53 insect pests associated to two widespread and economically valuable crops in the Euro-Mediterranean region, olive groves (Olea europaea subsp. europaea) and vineyards (Vitis vinifera subsp. vinifera). The study area was framed using 1004 square cells, each 10 × 10 km in size. Potential biocontrol services were determined at all those 10 × 10 km grid-cells in which each crop was present as the proportion of the realized out of all potential pairwise interactions between vertebrates and pests. Landscape correlates of biocontrol potential were also explored. Our work suggests that both birds and bats can effectively provide biocontrol services in olive groves and vineyards as they prey many insect pest species associated to both crops. Moreover, it demonstrates that these potential services are impacted by landscape-scale features and that this impact is consistent when evaluated over broad spatial extents. Thus, biocontrol potential by vertebrates significantly increases with increasing amount of natural area, while decreases with increasing area devoted to target crops, particularly olive groves. Overall, our study highlights the suitability of our interaction-based approach to perform spatially-explicit assessments of potential biocontrol services by vertebrates at local spatial scales and suggest its utility for integrating biodiversity and ecosystem services in conservation planning over broad spatial extents.


Author(s):  
A. A. Oso ◽  
A. J. Okunoye

Okra, an economically important vegetable crop with numerous benefits to human, is often attacked by large number of insect species. These insect species cause direct damage to okra plants and also serve as vectors of diseases resulting in economic loss. Control of these insect pests given reducing hunger and poverty, and fostering agricultural ecosystems becomes imperative.  This study aimed at the use of indigenous medicinal plant and a sub-lethal dose of synthetic insecticide to check the invasion of pests and performance of okra. The field laid in a randomized complete block design of four treatments replicated three times. The treatments included; Curcuma longa 5%, Curcuma longa 20%, lambda-cyhalothrin, and a control. Data were collected on insect pest species recovered after treatment application and yield of okra. All data were subjected to analysis of variance and differences between the treatment means were separated using Duncan’s multiple range test. C. longa (20%) compared effectively with the sub-lethal dose of lambdacyhalothin (0.5 ml/l) in their attack against the targeted pests. Although higher number and weight of pods were harvested from synthetically treated plots, the C. longa treated plots produced significantly higher number and weight of harvested pods when compared with untreated plots. Water extract of the rhizomes also conferred some protection against okra pests; we recommend that farmers in Ekiti State adopt this botanical against the notorious flea beetles especially when the profits accrue from okra sales outweigh their net investment.  


2016 ◽  
Vol 69 ◽  
pp. 285-289
Author(s):  
R.B. Chapman ◽  
J.W.M. Marris ◽  
J.B. Drummond

Producers and processors of cereal grains in New Zealand were invited in August 2015 to submit grain samples to allow extraction and identification of any insect pest species present Sixty grain samples were received of which 73 were infested with one or more insect species These were predominantly Coleoptera and Psocoptera The most frequently encountered beetle species were Oryzaephilus surinamensis Cryptolestes ferrugineus and Cortinicara hirtalis The Psocoptera were predominantly unidentified species of Liposcelis Sitophilus species and lepidopteran pests were notable by their absence The proportion of storage facilities infested by insects in this survey (73) was higher than two previous surveys (38 5063) and the proportion of storage facilities treated with insecticides (62) was lower than a previous survey (83)


Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 985
Author(s):  
Sandra Skendžić ◽  
Monika Zovko ◽  
Ivana Pajač Živković ◽  
Vinko Lešić ◽  
Darija Lemić

Climate change and invasive species are major environmental issues facing the world today. They represent the major threats for various types of ecosystems worldwide, mainly managed ecosystems such as agriculture. This study aims to examine the link between climate change and the biological invasion of insect pest species. Increased international trade systems and human mobility have led to increasing introduction rates of invasive insects while climate change could decrease barriers for their establishment and distribution. To mitigate environmental and economic damage it is important to understand the biotic and abiotic factors affecting the process of invasion (transport, introduction, establishment, and dispersal) in terms of climate change. We highlight the major biotic factors affecting the biological invasion process: diet breadth, phenological plasticity, and lifecycle strategies. Finally, we present alien insect pest invasion management that includes prevention, eradication, and assessment of the biological invasion in the form of modelling prediction tools.


Author(s):  
М. N. Shorokhov ◽  
V. A. Khilevskiy ◽  
А. N. Martynushkin ◽  
L. А. Burkova

Protective activities (including chemical ones) remain an integral part of crop production technologies. Assortment of chemicals is being changed all the time. Currently as a part of crop flies management it is permitted to use chemicals belonging to different structural classes. Major advantage, as can be seen in instance of pyrethroids, is the high initial effectiveness (95-100 %) and relatively low price, however its protective period is short. Introduction of seed dressing insecticides into the Russian market was a breakthrough in the insect pest management of crop flies and some other crop insect pests. Bayer CropScience AG developed and registered on the Russian market a first ever insecticide-fungicide seed dressing, Scenic Combi, CS (250+37.5+37.5+5 g/l) which contains 4 active substances (clothianidin, fluoxastrobin, prothioconazole, tebuconazole). This paper presents the data on the effectiveness of modern insecticides in crop flies management in the conditions of Omsk Oblast and Rostov Oblast for a period from 2011 to 2017. Sufficient biological effectiveness (80-100 %) of the wheat insect pest management is established when vegetative plants were sprayed with the following chemicals: Kungfu Super, Eforiya, BOREJ Neo, Thiacloprid + deltamethrin, Chlorpyrifos + cypermethrin, Shaman, Imidacloprid + alpha-cypermethrin, Imidor, Chlorpyrifos, Sharpej, Thiacloprid + lambda-cyhalothrin. The conclusion is made about the applicability of these chemicals providing its inclusion into the State catalogue of pesticides and agricultural chemicals.


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