ABSTRACT
We report for the first time that larvae of the genus Bothynus Hope (Coleoptera: Melolonthidae) caused economic damage to lucerne (Medicago sativa L., Fabaceae) crops in General Acha, province of La Pampa, Argentina. In two consecutive years (2021 and 2022), this insect infested 150 ha of lucerne, causing seedling losses of 80 ha. Based on soil sampling and laboratory insect rearing, the species was identified as Bothynus striatellus (Faimaire) (Coleoptera: Melolonthidae). Information is given here on the damage recorded in this forage crop, the density of the larvae observed at the time of damage assessment and the morphological characteristics of the third instar larvae reported in this crop in Argentina.
Subject(s)
Coleoptera , Crops, Agricultural , Larva , Medicago sativa , Animals , ArgentinaABSTRACT
The objective of this paper is to bring to the fore the type of economic analyses that have been carried out on the invasion of the Drosophila suzukii Matsumura (Diptera: Drosophilidae) and what has been learned. The analysis is limited to the original research articles published in peer-reviewed journals and book chapters. A total of 20 relevant studies are identified. The studies are analysed based on their main purpose, which is either economic impact assessment or economic evaluation of management programmes. The analysis also considers the key methodological points highlighted in recent reviews of the economic literature on alien invasive species. Over time, the focus of these studies has gradually shifted from raising awareness of the magnitude of the impact, particularly on agricultural production, to supporting the decision-making process concerning effective pest management. Most studies have been conducted from a private perspective, measuring private costs and providing guidance to the industry. However, some papers include, or focus on, the societal costs caused by the invasions of D. suzukii. This review has found few impact studies in the recently invaded areas and no economic evaluation of management programmes. There are not only geographical areas, but also themes that need more attention and analysis in the economic studies on D. suzukii. Assessing the economic effectiveness of integrated pest management programmes in specific settings, included the Latin American countries, is crucial.
Subject(s)
Drosophila , Insect Control , AnimalsABSTRACT
Rodents can cause significant damage to wheat-groundnut crops in developing countries, as well as to stored produce and infrastructure, affecting food security and income of small-holder farmers. Wheat (Triticum aestivum) and groundnuts (Arachis hypogea) are important cash crops for local farmers in Pakistan. Field experiments were performed to assess the extent of rodent damage to wheat-groundnut crops throughout their growth stages (i.e, germination, flowering/peg formation and maturity) in the agro-ecological zones of Pothwar Plateau, Pakistan. We used a quadrat method to record the number of damaged crop plants. On the basis of the trapping data four rodent species were captured from wheat-groundnut cropping systems which were responsible for causing damage, i.e., lesser bandicoot rat (Bandicota bengalensis) was the main species, followed by the short-tailed mole rat (Nesokia indica), the Indian gerbil (Tatera indica) and the bush rat (Golunda ellioti). In both crops, the maximum damage was recorded at crop maturity (10.7 and 14.4%, respectively). The lowest reported damage to wheat and groundnuts was at the germination stage (3.5% and 6.0%, respectively). The lower damage reported at germination could be due to availability of non-crop vegetation at field borders that may be a potential factor influencing damage. Our findings clearly show the considerable amount of damage caused by rodents to wheat-groundnut at maturity across all the agro-ecological zones of Pothwar and indicated that the small mammal composition was more related to maturity stage/season of crops, when the availability of food and climatic condition were favorable and having security under crop shelter. More detailed studies are needed to fully understand the population and breeding ecology of the relevant rodent pest species in relation to damage patterns to optimize management beyond individual structural measures.
Os roedores podem causar danos significativos às culturas de trigo e amendoim nos países em desenvolvimento, bem como aos produtos armazenados e infraestrutura, afetando a segurança alimentar e a renda dos pequenos agricultores. O trigo (Triticum aestivum) e o amendoim (Arachis hypogea) são culturas comerciais importantes para os agricultores locais no Paquistão. Experimentos de campo foram realizados para avaliar a extensão dos danos de roedores às culturas de trigo e amendoim ao longo de seus estágios de crescimento (ou seja, germinação, floração/formação e maturidade) nas zonas agroecológicas de Pothwar Plateau, Paquistão. Usamos um método de quadrat para registrar o número de plantas de cultura danificadas. Com base nos dados de armadilhagem foram capturadas quatro espécies de roedores de sistemas de cultivo de trigo-amendoim que foram responsáveis ââpor causar danos, ou seja, o rato-bandico-pequeno (Bandicota bengalensis) foi a espécie principal, seguido pelo rato-toupeira-de-cauda-curta (Nesokia indica), o gerbilo-da-índia (Tatera indica) e o rato-do-mato (Golunda ellioti). Em ambas as culturas, o dano máximo foi registrado na maturidade da cultura (10,7 e 14,4%, respectivamente). O menor dano relatado ao trigo e ao amendoim foi no estágio de germinação (3,5% e 6,0%, respectivamente). O menor dano relatado na germinação pode ser devido à disponibilidade de vegetação não cultivada nas bordas do campo, que pode ser um fator potencial que influencia o dano. Nossos resultados mostraram claramente a quantidade considerável de danos causados ââpor roedores ao trigo-amendoim na maturidade em todas as zonas agroecológicas de Pothwar e indicaram que a composição de pequenos mamíferos estava mais relacionada ao estágio de maturidade/estação das culturas quando a disponibilidade de alimentos e as condições climáticas eram favoráveis ââe com segurança sob abrigo de cultivo. Estudos mais detalhados são necessários para entender completamente a ecologia populacional e reprodutiva das espécies de pragas de roedores relevantes em relação aos padrões de danos para otimizar o manejo, além das medidas estruturais individuais.
Subject(s)
Animals , Arachis , Rodentia , Triticum , Agricultural PestsABSTRACT
Crop fungal diseases constitute a major cause of yield loss. The development of crop disease monitoring and forecasting tools is an important effort to aid farmers in adapting to climate variability and change. Recognizing weather as a main driver of fungal disease outbreaks, this work assesses the climate suitability for wheat blast (Magnaporthe oryzae pathotype Triticum, MoT) development in Asian wheat-producing countries. MOT was reported for the first time in Bangladesh in 2016 and could spread to other countries, provided that environmental conditions are suitable to spore development, distribution, and infection. With results from a generic infection model driven by air temperature and humidity, and motivated by the necessity to assess the potential distribution of MoT based on the response to weather drivers only, we quantify potential MOT infection events across Asia for the period 1980-2019. The results show a potential higher incidence of MOT in Bangladesh, Myanmar, and some areas of India, where the number of potential infection (NPI) events averaged up to 15 during wheat heading. Interannual trends show an increase in NPI over those three countries, which in turns show their higher interannual variability. Cold/dry conditions in countries such as Afghanistan and Pakistan appear to render them unlikely candidates for MOT establishment. The relationship between seasonal climate anomalies and NPI suggests a greater association with relative humidity than with temperature. These results could help to focus future efforts to develop management strategies where weather conditions are conducive for the establishment of MOT.
Subject(s)
Magnaporthe , Triticum , Triticum/microbiology , Plant Diseases/microbiology , Pakistan/epidemiology , Climate ChangeABSTRACT
Percolaspis ornata (Germar) (Coleoptera, Chrysomelidae) is known in Brazil as an important pest of cocoa in the states of Bahia and Espírito Santo. We recently identified a Chrysomelidae species feeding and causing damage to soybean, corn, and cotton crops in the state of Mato Grosso, Brazil. The species was identified as Percolaspis cf. ornata. Adults feed on young leaves and sprouts and, in many cases, cut the stem of seedlings, causing stand reduction and yield losses. Its attacks have been recorded since 2016 in the central region of Mato Grosso. Because of the importance of the state of Mato Grosso as the main grain producer in the country, it is necessary to monitor crops for the occurrence of this insect in the next harvests and the development of basic and applied studies aimed at defining management strategies for this emerging pest. This is the first record of P. cf. ornata causing damage to soybean, maize, and cotton crops in Brazil.
Subject(s)
Coleoptera , Animals , Brazil , Crops, Agricultural , Glycine max , Zea maysABSTRACT
Greater susceptibility to herbivory can arise as an effect of crop domestication. One proposed explanation is that defenses decreased intentionally or unintentionally during the domestication process, but evidence for this remains elusive. An alternative but nonexclusive explanation is presumed selection for higher nutritional quality. We used a metaanalytical approach to examine susceptibility to herbivores in fruit and seed crops and their wild relatives. Our analyses provide novel insights into the mechanisms of increased susceptibility by evaluating whether it can be attributed to either a reduction in herbivore defensive traits, including direct/indirect and constitutive/inducible defenses, or an increase in the nutritional content of crops. The results confirm higher herbivory and lower levels of all types of defenses in crops compared to wild relatives, although indirect defenses were more affected than direct ones. Contrary to expectations, nutritional quality was lower in crops than in wild relatives, which may enhance biomass loss to herbivores if they increase consumption to meet nutritional requirements. Our findings represent an important advance in our understanding of how changes in defensive and nutritional traits following domestication could influence, in combination or individually, crop susceptibility to herbivore attacks.
Subject(s)
Domestication , Herbivory , Fruit , Nutritive Value , SeedsABSTRACT
Wildlife is often blamed for causing damage to human activities, including agricultural practices and the result may be a conflict between human interests and species conservation. A formal assessment of the magnitude of damage is necessary to adequately conduct management practices and an assessment of the efficiency of different management practices is necessary to enable managers to mitigate the conflict with rural people. This study was carried out to evaluate the effectiveness of agricultural management practices and controlled hunting in reducing damage to subsistence annual crops at the Cotapata National Park and Natural Area of Integrated Management. The design included seven fields with modified agricultural practices, four fields subjected to control hunting, and five fields held as controls. We registered cultivar type, density, frequency of visiting species to the field, crops lost to wildlife, species responsible for damage, and crop biomass. Most frequent species in the fields were Dasyprocta punctata and Dasypus novemcinctus. Hunted plots were visited 1.6 times more frequently than agriculturally managed plots. Crop lost to wildlife averaged 7.28% at agriculturally managed plots, 4.59% in plots subjected to hunting, and 27.61% in control plots. Species mainly responsible for damage were Pecari tajacu, D. punctata, and Sapajus apella. We concluded that both management strategies were effective to reduce damage by >50% as compared to unmanaged crop plots. Rev. Biol. Trop. 62 (4): 1495-1507. Epub 2014 December 01.
El daño causado por fauna silvestre en cultivos agrícolas es una de las causas principales de conflicto dentro y fuera de áreas protegidas. Para un adecuado manejo del conflicto se requieren evaluaciones del daño y de la aplicación de distintos métodos de mitigación. El objetivo del trabajo fue evaluar la efectividad de prácticas agroculturales y cacería de control, para reducir daños por vertebrados silvestres en cultivos agrícolas anuales en el PN ANMI Cotapata. Se trabajó en siete parcelas con prácticas agroculturales, cuatro parcelas con cacería de control y cinco parcelas control, registrándose el tipo y densidad de cultivo, frecuencia de visitas de especies dañinas a huelleros, plantación perdida, especies responsables y biomasa de cosecha. Los resultados muestran que las especies más frecuentes fueron: Dasyprocta sp. y Dasypus novemcinctus, siendo estas 1.6 veces más frecuentes en parcelas con prácticas agroculturales. En promedio se perdió 7.3% de la plantación en parcelas agroculturales, 4.6% en parcelas sujetas a cacería de control, y 27.6% en parcelas control. Las principales especies responsables de las pérdidas fueron: P. tajacu, seguido por Dasyprocta sp. y S. apella. A través de estas estrategias de manejo, redujo las pérdidas en >50%, con lo cual se considera que los métodos puestos a prueba son útiles y se recomienda utilizarlos a gran escala con la consideración de que podría ser necesario innovar cada cierto tiempo, pues los animales silvestres tienden a acostumbrarse a los métodos de ahuyentamiento en ejecución.
Subject(s)
Animals , Humans , Animals, Wild , Conservation of Natural Resources , Crops, Agricultural , Animals, Wild/classification , Biomass , Bolivia , ForestsABSTRACT
This study aimed to assess the yield loss caused by capybaras in rural areas of Dourados-MS, their feeding periods, crop preferences and the landscape characteristics of farms that may affect the occurrence of capybara's herds. Semi-structured interviews in 24 different farms were done during a period between April 2010 and August 2011. Field observations were held at different times of the day, and also during the night in order to record peaks of the feeding behavior in six farms. Direct counting of capybaras along with the group of animals reported as seen by the farmers during the interviews was used to estimate the size of herds. Data was analyzed using the Principal Components Analyses and the Analytic Hierarchy Process. The average number of capybaras found in a regular herd was 18.8 ± 7.90 animals. The average number of capybara herd by farms was of 1.38 ± 0.92 while the average number of capybaras by farms was 32.33 ± 27.87. Capybaras selected rice (Oryza sativa) when it was available (14.5% of devastation in 1.18% of total planted area); however, the most eaten crop was corn (Zea mays) with 38.55% of loss rate in 16.17% of the total planted area. Capybaras ate mostly in the evening and during the night. The availability of water resources in the rural area predisposed the occurrence of capybara's herds.(AU)
Este estudo teve como objetivo avaliar a perda de safra causada por capivaras em áreas rurais de Dourados-MS, os períodos de alimentação, preferências por culturas instaladas e as características da paisagem nas fazendas que podem influenciar a ocorrência de rebanhos de capivaras. Entrevistas semiestruturadas em 24 propriedades diferentes foram feitas durante o período entre abril de 2010 e agosto de 2011. As observações de campo foram realizadas em diferentes momentos do dia e também durante a noite, a fim de registrar picos do comportamento alimentar em seis das fazendas amostradas. Contagens diretas de capivaras juntamente com as informações obtidas dos agricultores foram utilizadas para estimar o tamanho dos rebanhos. Utilizou-se a Análise de Componentes Principais e a Análise Multicriterial (Processo de Análise Hierárquica AHP) para as análises estatísticas. O número médio de capivaras por rebanho foi de 18,8 ± 7,90 animais. o número médio de grupos de capivaras por fazendas foi de 1,38 ± 0,92, e o número médio de capivaras por fazendas foi 32,33 ± 27,87. Capivaras selecionaram arroz (Oryza sativa) quando disponível (14,5% da predação em 1,18% do total da área plantada), no entanto, a cultura mais consumida foi o milho (Zea mays), com 38,55% de perdas em 16,17% da área plantada total, de acordo com os fazendeiros. Capivaras comeram principalmente ao anoitecer e durante a noite. A disponibilidade de recursos hídricos na área rural é um indicador da possibilidade de ocorrência de rebanhos de capivaras.(AU)
Subject(s)
Animals , Crops, Agricultural , Feeding Behavior/physiology , Rodentia/physiology , Rodentia/classification , SeasonsABSTRACT
This study aimed to assess the yield loss caused by capybaras in rural areas of Dourados-MS, their feeding periods, crop preferences and the landscape characteristics of farms that may affect the occurrence of capybara's herds. Semi-structured interviews in 24 different farms were done during a period between April 2010 and August 2011. Field observations were held at different times of the day, and also during the night in order to record peaks of the feeding behavior in six farms. Direct counting of capybaras along with the group of animals reported as seen by the farmers during the interviews was used to estimate the size of herds. Data was analyzed using the Principal Components Analyses and the Analytic Hierarchy Process. The average number of capybaras found in a regular herd was 18.8 ± 7.90 animals. The average number of capybara herd by farms was of 1.38 ± 0.92 while the average number of capybaras by farms was 32.33 ± 27.87. Capybaras selected rice (Oryza sativa) when it was available (14.5% of devastation in 1.18% of total planted area); however, the most eaten crop was corn (Zea mays) with 38.55% of loss rate in 16.17% of the total planted area. Capybaras ate mostly in the evening and during the night. The availability of water resources in the rural area predisposed the occurrence of capybara's herds.
Este estudo teve como objetivo avaliar a perda de safra causada por capivaras em áreas rurais de Dourados-MS, os períodos de alimentação, preferências por culturas instaladas e as características da paisagem nas fazendas que podem influenciar a ocorrência de rebanhos de capivaras. Entrevistas semiestruturadas em 24 propriedades diferentes foram feitas durante o período entre abril de 2010 e agosto de 2011. As observações de campo foram realizadas em diferentes momentos do dia e também durante a noite, a fim de registrar picos do comportamento alimentar em seis das fazendas amostradas. Contagens diretas de capivaras juntamente com as informações obtidas dos agricultores foram utilizadas para estimar o tamanho dos rebanhos. Utilizou-se a Análise de Componentes Principais e a Análise Multicriterial (Processo de Análise Hierárquica – AHP) para as análises estatísticas. O número médio de capivaras por rebanho foi de 18,8 ± 7,90 animais. o número médio de grupos de capivaras por fazendas foi de 1,38 ± 0,92, e o número médio de capivaras por fazendas foi 32,33 ± 27,87. Capivaras selecionaram arroz (Oryza sativa) quando disponível (14,5% da predação em 1,18% do total da área plantada), no entanto, a cultura mais consumida foi o milho (Zea mays), com 38,55% de perdas em 16,17% da área plantada total, de acordo com os fazendeiros. Capivaras comeram principalmente ao anoitecer e durante a noite. A disponibilidade de recursos hídricos na área rural é um indicador da possibilidade de ocorrência de rebanhos de capivaras.
Subject(s)
Animals , Crops, Agricultural , Feeding Behavior/physiology , Rodentia/physiology , Rodentia/classification , SeasonsABSTRACT
Damage caused by capybaras in agroecossystems in Brazil has been frequently observed. The objective of this study was to describe and quantify the actual damage caused by capybaras in a corn field, aiming to get basic information on how, how much, and where these damage occur. Systematic sampling indicated that 26% of the planted area were damaged by capybaras, and the highest percentage of damage occurred on the border of the corn field (t=4.5698, p=0.0001). Damage in areas adjacent to a forest fragment was significantly higher (t=13.6198, p=0.0001), suggesting that the strategy of area utilization for feeding was related to the proximity of the resources "forest" and "water". Avoiding corn plantation in areas adjacent to forest fragments used by capybaras and, when possible, controlling capybara population may lead to a reduction of damage occurrence in agroecossystems.
Danos causados por capivaras em culturas agrícolas no Brasil têm sido freqüentemente reportados. O objetivo deste estudo foi descrever e quantificar os danos causados por capivaras em um campo de milho, visando obter informações básicas de quanto, como e onde esse dano ocorre. Através da amostragem sistemática obteve-se que 26% da área plantada foi danificada por capivaras, sendo que a maior porcentagem dos danos localizou-se nas bordas do campo de milho (t=4.5698, p=0.0001). O dano em áreas adjacentes ao fragmento de mata foi significativamente maior do que no restante do terreno (t=13.6198, p=0.0001), sugerindo que a estratégia de utilização da área de alimentação pela capivara relaciona-se com o fator proximidade dos recursos "floresta" e "água". Evitar o plantio de milho em áreas adjacentes a fragmentos florestais utilizados por capivaras e, quando possível adotar práticas de controle populacional, podem significar a redução da ocorrência de danos causados aos agroecossistemas.
ABSTRACT
Damage caused by capybaras in agroecossystems in Brazil has been frequently observed. The objective of this study was to describe and quantify the actual damage caused by capybaras in a corn field, aiming to get basic information on how, how much, and where these damage occur. Systematic sampling indicated that 26% of the planted area were damaged by capybaras, and the highest percentage of damage occurred on the border of the corn field (t=4.5698, p=0.0001). Damage in areas adjacent to a forest fragment was significantly higher (t=13.6198, p=0.0001), suggesting that the strategy of area utilization for feeding was related to the proximity of the resources "forest" and "water". Avoiding corn plantation in areas adjacent to forest fragments used by capybaras and, when possible, controlling capybara population may lead to a reduction of damage occurrence in agroecossystems.
Danos causados por capivaras em culturas agrícolas no Brasil têm sido freqüentemente reportados. O objetivo deste estudo foi descrever e quantificar os danos causados por capivaras em um campo de milho, visando obter informações básicas de quanto, como e onde esse dano ocorre. Através da amostragem sistemática obteve-se que 26% da área plantada foi danificada por capivaras, sendo que a maior porcentagem dos danos localizou-se nas bordas do campo de milho (t=4.5698, p=0.0001). O dano em áreas adjacentes ao fragmento de mata foi significativamente maior do que no restante do terreno (t=13.6198, p=0.0001), sugerindo que a estratégia de utilização da área de alimentação pela capivara relaciona-se com o fator proximidade dos recursos "floresta" e "água". Evitar o plantio de milho em áreas adjacentes a fragmentos florestais utilizados por capivaras e, quando possível adotar práticas de controle populacional, podem significar a redução da ocorrência de danos causados aos agroecossistemas.