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601 result(s) for "fall armyworm"
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Agricultural Robot-Centered Recognition of Early-Developmental Pest Stage Based on Deep Learning: A Case Study on Fall Armyworm (Spodoptera frugiperda)
Accurately detecting early developmental stages of insect pests (larvae) from off-the-shelf stereo camera sensor data using deep learning holds several benefits for farmers, from simple robot configuration to early neutralization of this less agile but more disastrous stage. Machine vision technology has advanced from bulk spraying to precise dosage to directly rubbing on the infected crops. However, these solutions primarily focus on adult pests and post-infestation stages. This study suggested using a front-pointing red-green-blue (RGB) stereo camera mounted on a robot to identify pest larvae using deep learning. The camera feeds data into our deep-learning algorithms experimented on eight ImageNet pre-trained models. The combination of the insect classifier and the detector replicates the peripheral and foveal line-of-sight vision on our custom pest larvae dataset, respectively. This enables a trade-off between the robot’s smooth operation and localization precision in the pest captured, as it first appeared in the farsighted section. Consequently, the nearsighted part utilizes our faster region-based convolutional neural network-based pest detector to localize precisely. Simulating the employed robot dynamics using CoppeliaSim and MATLAB/SIMULINK with the deep-learning toolbox demonstrated the excellent feasibility of the proposed system. Our deep-learning classifier and detector exhibited 99% and 0.84 accuracy and a mean average precision, respectively.
Diets for in vivo inoculation of Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) (Lefavirales: Baculoviridae)
The Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) has been studied and applied in controlling the fall armyworm, Spodoptera frugiperda. This pest serves as the primary host for in vivo replication of this biological control agent. For viral inoculation, the virus is introduced into an artificial diet, which is also used for large-scale host multiplication. In this study, we tested more cost-effective diets to optimize the viral inoculation stage. Each diet was treated with the virus and monitored daily for host mortality. Viral production parameters were subsequently quantified. Although the evaluated diets did not achieve the same yield levels as those used for large-scale S. frugiperda multiplication, the D7 diet showed similar cost-effectiveness to the D2 diet in terms of producing one dose per hectare. Additionally, larvae consuming diets higher in crude protein exhibited reduced viral polyhedra production.
Canibalism in the larval instars of Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae): temperature and food quantity
Cannibalism is a frequent behavior in Spodoptera frugiperda (J. E. Smith, 1797) larvae either in the field or in a laboratory. The purpose of this work was to investigate the factors temperature and food quantity on the cannibal behavior in instars of this insect under laboratory conditions. The neonates were conditioned at temperatures of 22, 25, 28 and 31 ± 1°C until they reached the 3rd, 4th, and 5th instar. The number of 20 larvae were transferred to different gerbox® with the amount of food varying from 0, 5, 10, 15, and 20 g of artificial diet. Cannibalism was evaluated after 72 hours. In all the instars evaluated, the larvae showed cannibalistic behavior as a function of temperature and amount of food. The amount of 15 g of artificial diet is sufficient to feed the 3rd and 4th instar larval for 72h, regardless of temperature. For the 5th instar this amount is 10 g.
Fungal and viral entomopathogens as a combined strategy for the biological control of fall armyworm larvae in maize
Background The fall armyworm Spodoptera frugiperda is one of the major pests in maize crops, causing important production losses. The pest has rapidly spread worldwide, generating an urgent need to develop efficient and sustainable strategies for its control. In this work, the potential of integrating nucleopolyhedrovirus- (NPV) and the fungus Metarhizium rileyi to control S. frugiperda larvae was evaluated under laboratory, greenhouse, and field conditions. Methods The mortality of S. frugiperda larvae was evaluated after the application of NPV and M. rileyi alone or in combination using three concentrations (high, medium and low) under laboratory conditions. Then, two greenhouse trials using maize plants were carried out to evaluate the effect of individual or combined applications of NPV and M. rileyi on S. frugiperda mortality (first trial) and fresh damage (second trial). Finally, a trial under field conditions was conducted to evaluate the performance of the treatment selected in the greenhouse assay. Results The combined use of NPV: M. rileyi applied simultaneously showed an additive effect in laboratory, causing higher larval mortality than the biocontrol agents used separately. This effect was evident in the mixtures using the concentration levels high:medium, medium:medium, and medium:high. Under greenhouse conditions, the use of a 50:50 ratio of the two entomopathogens also caused higher larval mortality and a significantly reduced insect damage to plants. Finally, under field conditions, the individual or sequential application of NPV and M. rileyi using 100% of their recommended doses, and the simultaneous application of both entomopathogens at 50% of their recommended doses, significantly reduced the recent foliar damage to levels under the threshold for economic losses (30% fresh damage) while the damage reached 43% when control measures were not used. Conclusion The combined application of NPV and M. rileyi (two biocontrol agents with different mode of action) demonstrated an additive effect that allows to reduce to half their recommended application doses. In this context, the integration of both entomopathogens is a promising strategy to manage S. frugiperda, contributing to improve the economic feasibility of biological control tools for the sustainable fall armyworm management.
Field-Evolved Resistance of the Fall Armyworm (Lepidoptera: Noctuidae) to Synthetic Insecticides in Puerto Rico and Mexico
The fall armyworm, Spodoptera frugiperda (J. E. Smith), is one of the main pests of corn in many areas of the American continent. The reliance on pesticides to control fall armyworm has led to the development of insecticide resistance in many regions. We determined the resistance levels of fall armyworm to insecticides of different modes of action in fall armyworm populations from Puerto Rico and several Mexican states with different insecticide use patterns. Mexican populations that expressed higher resistance ratios (RR50) were: Sonora (20-fold to chlorpyriphos), Oaxaca (19-fold to permethrin), and Sinaloa (10-fold to flubendamide). The Puerto Rico population exhibited a remarkable field-evolved resistance to many pesticides. The RR50 to the insecticides tested were: flubendiamide (500-fold), chlorantraniliprole (160-fold), methomyl (223-fold), thiodicarb (124-fold), permethrin (48-fold), chlorpyriphos (47-fold), zeta-cypermethrin (35-fold), deltamethrin (25-fold), triflumuron (20-fold), spinetoram (14-fold). Spinosad (eightfold), emamectin benzoate and abamectin (sevenfold) displayed lower resistance ratio. However, these compounds are still effective to manage fall armyworm resistance in Puerto Rico. Fall armyworm populations from Mexico show different levels of susceptibility, which may reflect the heterogeneity of the pest control patterns in this country. The status of insecticide resistance in the fall armyworm from Puerto Rico indicates a challenging situation for the control of this pest with these insecticides in the close future. Lessons learned from this research might be applied in regions with recent invasions of fall armyworm in Africa.
Chemical Control and Insecticide Resistance in Spodoptera frugiperda (Lepidoptera: Noctuidae)
Insecticides and genetically modified Bt crops are the main tools for control of the fall armyworm, Spodoptera frugiperda (J.E. Smith). Since its invasion of Africa, the Far East, and Australia where Bt crops are largely absent, insecticide use has increased and reduced susceptibility to several insecticides used for decades in its native distribution area have been reported. Poor efficacy at field-level is sometimes incorrectly ascribed to pest resistance, while numerous other factors influence efficacy at field-level. In this paper, we review the history of insecticide resistance in S. frugiperda and discuss the influence that life history traits, migration ecology, and chemical control practices may have on control efficacy and resistance evolution. The indirect role that poor national policies have on pesticide use practices, and indirectly on control efficacy and selection pressure is discussed. Evidence shows that local selection for resistance drives resistance evolution. Integrated pest management, rather than reliance on a single tactic, is the best way to suppress S. frugiperda numbers and the over-use of insecticides which selects for resistance.
Fall Armyworm: Impacts and Implications for Africa
The appearance of Fall Armyworm (FAW) (Spodoptera frugiperda) in Africa has caused much consternation: \"The hungry caterpillar threatening a global food crisis\", according to a headline in the Guardian newspaper. The UK Department for International Development (DFID) commissioned CABI to compile an evidence note, which was published by CABI in September 2017. This article is a summary of the evidence note, which aimed to assess the potential impact of FAW in Africa if left uncontrolled, and recommend and prioritise control options. The first confirmed reports of FAW were from West Africa in early 2016. Research to date suggests that both strains of FAW that are found in the Americas entered Africa, perhaps as stowaways on commercial aircraft, either in cargo containers or airplane holds, before subsequent widespread dispersal by the wind. The probability is high (>90%) that the introduction to Africa was from the characterised Florida strain of FAW, which is restricted to the eastern seaboard of the USA, and the Caribbean islands. Based on information from literature searches, personal communications and internet mining, as for August 2017 28 countries have confirmed the presence of FAW. A further nine countries suspect its presence, or are awaiting official confirmation of the pest in the country. Two countries (Somalia and Djibouti) have conducted surveys and not found any FAW. Using distribution and climate data collected from South America and in Ghana and Zambia, models were used to investigate the environmental (climatic) factors affecting the distribution of FAW. Results from multiple models have been combined to produce an environmental suitability index for FAW across Africa. Fall Armyworm (FAW) in Africa has the potential to cause maize yield losses in a range from 8.3 to 20.6m tonnes per annum, in the absence of any control methods, in just 12 of Africa's maize-producing countries. This represents a range of 21%-53% of the annual production of maize averaged over a three year period in these countries. The value of these potential losses is estimated at between $2,481m and $6,187m. FAW should be expected to spread throughout suitable habitats in mainland sub-Saharan Africa within the next few cropping seasons. Northern Africa and Madagascar are also at risk. As of August 2017, the pest has been confirmed present in 28 countries in Africa (compared to 12 in April 2017), with suspected presence in a further 9 countries. Control of FAW requires an integrated pest management (IPM) approach. Immediate recommendations include (i) awareness raising campaigns on FAW symptoms, early detection and control, including beneficial agronomic practices; (ii) national preparation and communication of a list of recommended, regulated pesticides and biopesticides and their appropriate application methods. Work should also start immediately to (i) assess preferred crop varieties for resistance or tolerance to FAW; (ii) introduce classical biological control agents from the Americas. A conducive policy environment should promote lower risk pest management approaches.
Susceptibility of Louisiana and Florida Populations of Spodoptera frugiperda (Lepidoptera: Noctuidae) to Pyramided Bt Corn Containing Genuity®Vt Double Pro™ and Smartstax™ Traits
The fall armyworm, Spodoptera frugiperda (J. E. Smith), is a target species of transgenic corn containing pyramided Bt genes in the United States. During 2011, a total of 149 F2 two-parental family lines were established using single-pairing of S. frugiperda collected from 3 locations in Louisiana and Florida. This study examined the susceptibility of these F2 two-parental family lines to 2 commonly used pyramided Bt corn traits, Genuity®VT Double Pro™ and Genuity®SmartStax™. Nine out of the 149 family lines showed less susceptibility to the leaf tissue of Genuity®VT Double Pro™ or Genuity®SmartStax plants. Larvae of these 9 family lines exhibited significant survivorship and growth on leaf tissue of the Bt corn plants. Two laboratory colonies were established from the F2 survivors of 2 of the 9 family lines. However, larvae from both colonies could not survive on whole plants of their corresponding Bt corn products in the greenhouse, suggesting these families were not resistant to the pyramided Bt corn traits. The results suggest that the pyramided Bt corn products containing Genuity®VT Double Pro™ or Genuity®SmartStax™ corn traits are effective in protecting against S. frugiperda.
Invasion of fall armyworm (Spodoptera frugiperda) in India
Fall armyworm (FAW; Spodoptera frugiperda (J. E. Smith)) is emerging as the most destructive pest of maize in India since its report in May 2018. Its rapid spread to more than 90% of maize-growing areas of diverse agro-ecologies of India within a span of 16 months presents a major challenge to smallholder maize farmers, maize-based industry, as well as food and nutritional security. FAW has been reported from other crops as well like sorghum and millets with varied proportion of economic damage. In this review, the transboundary movement of FAW, role of ecology, its spread and damage are discussed. Management of FAW by developing and deploying various pest management tools is elaborated. The role of agroecological measures for reducing FAW damage with African experiences has also been highlighted.
The Effect of Temperature on the Development of Spodoptera frugiperda (Lepidoptera: Noctuidae)
The fall armyworm (Spodoptera frugiperda) is a pest of tropical origin which recently invaded Africa, the Far East and Australia. Temperature, therefore, plays an important role in its invasion biology, since this pest does not go into diapause. The aim of this study was to determine the development rate of S. frugiperda at different temperatures and to calculate the number of degree-days (°D) required for each stage to complete its development. This study was conducted at five different temperatures—18, 22, 26, 30 and 32 ± 1 °C. Larvae were reared individually in Petri dishes with sweetcorn kernels provided as food. The development rate of S. frugiperda increased linearly with increasing temperatures between 18 and 30 °C and larval survival was the highest between 26 and 30 °C. The optimal range for egg, larval and egg-to-adult development was between 26 and 30 °C. The optimum temperature with the fastest larval development rate and lowest mortality was at 30 °C. The pupal development period ranged between 7.82 and 30.68 days (32–18 °C). The minimum temperature threshold for egg and larva development was 13.01 and 12.12 °C, respectively, 13.06 °C for pupae and 12.57 °C for egg-to-adult development. Degree-day requirements for the development of the respective life cycle stages of S. frugiperda were 35.68 ± 0.22 for eggs, 204.60 ± 1.23 °D for larvae, 150.54 ± 0.93 °D for pupae and 391.61 ± 1.42 °D for egg-to-adult development.