RESUMO
The leafroller Argyrotaenia sphaleropa (Meyrick) is an important pest of temperate fruits. Its biology and population dynamics are strongly influenced by temperature. In this context, this study aims to select a mathematical model that accurately describes the temperature-dependent development rate of A. sphaleropa and applies this model to predict the impact of climate change on the number of annual generations (voltinism) of the pest in southern Brazil. Nine mathematical models were employed to fit the species' developmental rate at different constant temperatures. Voltinism was projected using climate data from the current period (1994-2013) and projections for 2050 and 2070. The Brière-1 model (D(T) = aT(T-TL)(TH-T)1/2) provided the best fit for the temperature-dependent developmental rate of A. sphaleropa. According to this model, the regions with the highest voltinism under current climatic conditions are the northern and central areas of Paraná, the western and northeastern regions of Santa Catarina, and northwestern Rio Grande do Sul. The model also predicts a rise in A. sphaleropa voltinism as a consequence of climate change, especially in the mountainous regions of Santa Catarina and Rio Grande do Sul, with projected increases of up to 25.1%. These regions encompass most areas where temperate fruits used as hosts by the leafroller are cultivated. This study represents a significant advancement in understanding the implications of global warming on A. sphaleropa voltinism and suggests that forthcoming climatic conditions will likely favor the species across much of southern Brazil.
Assuntos
Mudança Climática , Frutas , Brasil , Animais , Modelos Teóricos , Hemípteros , Temperatura , Dinâmica PopulacionalRESUMO
BACKGROUND: Temperature plays a critical role in the development and reproductive process of insects, therefore understanding how insects respond to temperature is vital for comprehending and predicting their population dynamics, particularly when it comes to agricultural pests. Spodoptera eridania Stoll is a polyphagous pest that has recently expanded its distribution beyond its native range. In this study, we assessed the impact of temperature on the reproduction of S. eridania and used the obtained data to develop an oviposition model that could be used to predict egg-laying behavior under field conditions. The reproductive parameters were evaluated at temperatures of 15, 20, 25, 28, and 32 °C. RESULTS: Temperature had a significant impact on the reproductive parameters examined. Overall, as temperature increased, the pre-oviposition period, oviposition period, and longevity decreased. Total fecundity exhibited a bell-shaped response to temperature, with peak egg-laying observed at 20 and 25 °C. In line with the experimental data, our model predicted higher rates of oviposition between 20 and 26 °C, thus reinforcing that this temperature range may represent the optimal conditions for the reproduction of S. eridania. CONCLUSION: The findings from our study provide a significant contribution to the understanding of the ecology of an important agricultural pest. The information generated can have practical applications in developing control strategies by enabling the aligning of the timing of control measures with peaks of reproductive activity. © 2023 Society of Chemical Industry.
Assuntos
Espécies Introduzidas , Oviposição , Animais , Feminino , Spodoptera , Temperatura , ReproduçãoRESUMO
BACKGROUND: Brazil is among the world's largest producers of eucalyptus and the damage caused by native and invasive insect pests is one of the main factors affecting eucalyptus yield. The recent history of biological invasions of eucalyptus pests in Brazil prompts demand for phytosanitary measures to prevent new invasions. This study used ecological niche models to estimate suitable areas for nine eucalyptus pests. This information was used to assess the potential ports of entry, generate invasion risk maps considering the likelihood of introducing invasive species, and estimate the eucalyptus producing municipalities and areas within the species' suitable range. RESULTS: A large distribution range was predicted for Eucalyptolyma maideni (Hempitera: Aphalaridae), Orgya postica (Lepidoptera: Erebidae), Sinoxylon anale (Coleoptera: Bostrichidae), and Trachymela sloanei (Coleoptera: Chrysomelidae) in Brazil, while a comparatively smaller distribution was predicted for Ophelimus maskelli (Hymenoptera: Eulophidae), Mnesampela privata (Lepidoptera: Geometridae), Paropsis atomaria (Coleoptera: Chrysomelidae), Paropsisterna beata, and P. cloelia (Coleoptera: Chrysomelidae). High-risk areas of invasion near airports and seaports were predicted mainly in southern, southeastern, and northeastern Brazil. A large proportion of the municipalities (24.4% to 93.7%) and areas with eucalyptus plantations (31.9% to 98.3%) are within the climatically suitable areas estimated for the pests, especially in southern and southeastern regions, which comprises 61.5% of the Brazilian eucalyptus production. CONCLUSION: The results indicate that eucalyptus forestry may be significantly impacted by biological invasion. The findings provided by our study can assist decision-makers in developing phytosanitary measures to prevent new invasions of forest pests in Brazil. © 2022 Society of Chemical Industry.
Assuntos
Besouros , Eucalyptus , Himenópteros , Mariposas , Animais , Brasil , Agricultura FlorestalRESUMO
The small tomato borer, Neoleucinodes elegantalis (Guenée, 1854) is a multivoltine pest of tomato and other cultivated solanaceous plants. The knowledge on how N. elegantalis respond to temperature may help in the development of pest management strategies, and in the understanding of the effects of climate change on its voltinism. In this context, this study aimed to select models to describe the temperature-dependent development rate of N. elegantalis and apply the best models to evaluate the impacts of climate change on pest voltinism. Voltinism was estimated with the best fit non-linear model and the degree-day approach using future climate change scenarios representing intermediary and high greenhouse gas emission rates. Two out of the six models assessed showed a good fit to the observed data and accurately estimated the thermal thresholds of N. elegantalis. The degree-day and the non-linear model estimated more generations in the warmer regions and fewer generations in the colder areas, but differences of up to 41% between models were recorded mainly in the warmer regions. In general, both models predicted an increase in the voltinism of N. elegantalis in most of the study area, and this increase was more pronounced in the scenarios with high emission of greenhouse gases. The mathematical model (74.8%) and the location (9.8%) were the factors that mostly contributed to the observed variation in pest voltinism. Our findings highlight the impact of climate change on the voltinism of N. elegantalis and indicate that an increase in its population growth is expected in most regions of the study area.
Assuntos
Aquecimento Global , Modelos Biológicos , Mariposas/crescimento & desenvolvimento , Animais , Reprodução , TemperaturaRESUMO
The development, survival, and reproduction of ectothermic organisms such as insects are strongly influenced by temperature. Because insects respond to temperature by accelerating or reducing their development rate, population growth is directly associated with temperature variations. Here, daily minimum and maximum temperatures and degree-day model approaches were used to estimate the number generation per year (voltinism) of Mythimna sequax Franclemont, Neoleucinodes elegantalis (Guenée), Spodoptera cosmioides (Walker), and Spodoptera eridania (Cramer) over a 34-year period in southern Brazil. Additionally, we assessed the effects of El Niño Southern Oscillation (ENSO) events on voltinism. While an increased number of generations were estimated in warmer regions, comprising mainly northwestern Paraná, fewer generations were estimated in the colder regions of Santa Catarina and Rio Grande do Sul. For all species, the location was the factor that explained most of the variation observed in voltinism (average of 76.9%). Inter-annual changes in voltinism also varied depending on location, and differences of up to five generations among years were obtained in colder regions. On the other hand, ENSO events had a minor influence on the species voltinism. Our findings provide an important contribution to the understanding of spatio-temporal variations in voltinism of insects, and how temperature changes may increase their population growth.
Assuntos
Mariposas , Temperatura , Animais , Brasil , Fertilidade , Mariposas/fisiologia , Reprodução , Análise Espaço-Temporal , Spodoptera/fisiologiaRESUMO
Isoxaflutole (IFT) é um herbicida utilizado para o controle em pré-emergência de uma ampla variedade de plantas daninhas de folha larga e gramíneas, especialmente quando há resistência a outros herbicidas, como glyphosate e atrazine. Apesar de seu potencial como herbicida ter sido identificado no início dos anos 90, IFT ainda é considerado um ingrediente ativo novo no Brasil e pouco se sabe sobre seus efeitos, principalmente acerca da ecotoxicidade dos produtos formulados para grupos da macro e mesofauna do solo. Este estudo teve como objetivo avaliar efeitos comportamentais, agudos e crônicos (fuga, letalidade e reprodução) do produto comercial Provence® 750 WG (750 g i.a. L-1 isoxaflutole) nos organismos de teste Eisenia andrei (minhoca) e Folsomia candida (colêmbolo) usando normas padronizadas ISO. Os resultados mostraram que as minhocas apresentam comportamento de fuga apenas em doses >300 vezes a dose de campo e redução na reprodução em doses >150 vezes a dose de campo. Para os colêmbolos não foi obtida resposta de fuga, letalidade ou reprodução nas doses avaliadas. A partir dos resultados de laboratório, presume-se que o produto comercial Provence® não apresenta toxicidade para minhocas e colêmbolos, mesmo em doses muito acima à dose de campo, garantindo a segurança das comunidades do solo.
Isoxaflutole (IFT) is a pre-emergence herbicide used to control of a wide range of broadleaf and grass weeds, especially those resistant to other herbicide classes, such as glyphosate and atrazine. Although its herbicidal potential was identified in the early 90s, IFT is still a new active ingredient in Brazil and little is known about its effects, mainly regarding to ecotoxicity of formulated products to soil macro and mesofauna groups. This study aimed to assess behavioral, acute, and chronical effects (avoidance, lethality, and reproduction) of the commercial product ProvenceTM 750 WG (750 g a.i. L-1 isoxaflutole) on the test organisms Eisenia andrei (earthworms) and Folsomia candida (collembolans) using standardized ISO guidelines. The results showed the avoidance of the earthworm species only at >300 times the predicted field doses, as well as a decrease in reproduction over >150 times the predicted field dose. Neither the avoidance, nor lethality or reproduction response were found for the collembolan species. The laboratory results showed that it is possible to assume that ProvenceTM is not toxic to earthworms and collembolans, even at the highest field dose applied, ensuring the safety of soil communities.
Assuntos
Animais , Agroquímicos , Ecotoxicologia , Herbicidas/administração & dosagem , Invertebrados , OligoquetosRESUMO
Isoxaflutole (IFT) é um herbicida utilizado para o controle em pré-emergência de uma ampla variedade de plantas daninhas de folha larga e gramíneas, especialmente quando há resistência a outros herbicidas, como glyphosate e atrazine. Apesar de seu potencial como herbicida ter sido identificado no início dos anos 90, IFT ainda é considerado um ingrediente ativo novo no Brasil e pouco se sabe sobre seus efeitos, principalmente acerca da ecotoxicidade dos produtos formulados para grupos da macro e mesofauna do solo. Este estudo teve como objetivo avaliar efeitos comportamentais, agudos e crônicos (fuga, letalidade e reprodução) do produto comercial Provence® 750 WG (750 g i.a. L-1 isoxaflutole) nos organismos de teste Eisenia andrei (minhoca) e Folsomia candida (colêmbolo) usando normas padronizadas ISO. Os resultados mostraram que as minhocas apresentam comportamento de fuga apenas em doses >300 vezes a dose de campo e redução na reprodução em doses >150 vezes a dose de campo. Para os colêmbolos não foi obtida resposta de fuga, letalidade ou reprodução nas doses avaliadas. A partir dos resultados de laboratório, presume-se que o produto comercial Provence® não apresenta toxicidade para minhocas e colêmbolos, mesmo em doses muito acima à dose de campo, garantindo a segurança das comunidades do solo.(AU)
Isoxaflutole (IFT) is a pre-emergence herbicide used to control of a wide range of broadleaf and grass weeds, especially those resistant to other herbicide classes, such as glyphosate and atrazine. Although its herbicidal potential was identified in the early 90s, IFT is still a new active ingredient in Brazil and little is known about its effects, mainly regarding to ecotoxicity of formulated products to soil macro and mesofauna groups. This study aimed to assess behavioral, acute, and chronical effects (avoidance, lethality, and reproduction) of the commercial product ProvenceTM 750 WG (750 g a.i. L-1 isoxaflutole) on the test organisms Eisenia andrei (earthworms) and Folsomia candida (collembolans) using standardized ISO guidelines. The results showed the avoidance of the earthworm species only at >300 times the predicted field doses, as well as a decrease in reproduction over >150 times the predicted field dose. Neither the avoidance, nor lethality or reproduction response were found for the collembolan species. The laboratory results showed that it is possible to assume that ProvenceTM is not toxic to earthworms and collembolans, even at the highest field dose applied, ensuring the safety of soil communities.(AU)
Assuntos
Animais , Ecotoxicologia , Herbicidas/administração & dosagem , Invertebrados , Oligoquetos , AgroquímicosRESUMO
Metsulfuron-methyl is a common active ingredient recommended for use in pre- and post-emergence control of annual grasses and broadleaf weeds in crops, usually applied with mineral oil as adjuvant to enhance its efficiency. Despite the increasing use of this herbicide, there are no information on its ecotoxicity effects to soil fauna. Avoidance and lethality tests were performed with earthworms and collembolans using tropical artificial soil contaminated with formulated products Ally® (600 g L-1 metsulfuron-methyl) and Assist® (756 g L-1 mineral oil) as adjuvant. Lethality test with earthworms showed no difference when tested with or without adjuvant. When Ally® was tested alone, it caused avoidance behavior only at high concentrations (5000 and 10,000 times field predicted dose). However, Assist® addition changed the response of soil invertebrates increasing the avoidance even at field predicted doses. The toxicity of the adjuvant was confirmed in tests exposing collembolans and earthworms to Assist® alone resulting in avoidance behavior. The results clearly show that the addition of mineral oil enhanced the ecotoxicity of metsulfuron-methyl. This study provides an important contribution to the knowledge on the toxicity of metsulfuron-methyl and indicates that adjuvants should be considered in risk assessment of pesticides, considering that under field conditions, these products are applied together.
Assuntos
Artrópodes/efeitos dos fármacos , Sulfonatos de Arila/toxicidade , Ecotoxicologia/métodos , Oligoquetos/efeitos dos fármacos , Poluentes do Solo/toxicidade , Animais , Artrópodes/fisiologia , Sulfonatos de Arila/administração & dosagem , Aprendizagem da Esquiva/efeitos dos fármacos , Herbicidas/administração & dosagem , Herbicidas/toxicidade , Oligoquetos/fisiologia , Poluentes do Solo/administração & dosagemRESUMO
ABSTRACT The serious economic loss caused Plutella xylostella L., 1758 in several regions of the world has prompted a demand for alternative management strategies. In this context, understanding the key factors governing the population dynamics of the pest is important for development of management strategies. This study aimed to identify the larval parasitoids associated with P. xylostella and investigate the biotic (crop subspecies, plant age and parasitism) and abiotic factors (minimum and maximum temperatures, rainfall, relative humidity and planting season) affecting the population dynamics of the pest in organic crops located in Southern Paraná State, Brazil. Despite the continuous and abundant availability of host plants throughout the year, P. xylostella occurred between June and November, and the largest peaks of abundance were observed between August and September, when low temperatures and rainfall were recorded. According to the stepwise regression analysis, P. xylostella was more abundant in broccoli during winter. Neither temperature, nor rainfall significantly influenced pest abundance. Four species of larval parasitoids were identified associated with the pest, of which Diadegma leontiniae (Brèthes) (Hymenoptera: Ichneumonidae), Apanteles piceotrichosus Blanchard (Hymenoptera: Braconidae) and Siphona sp. Meigen (Diptera: Tachinidae) were abundant, while Oomyzus sokolowskii (Kurdjumov) (Hymenoptera: Eulophidae) was rarely found. Parasitism was the major factor influencing population dynamics of P. xylostella, contributing to 48% of the variation in pest abundance. These results show the importance of larval parasitoids complex in regulating P. xylostella population and that the temperature and rainfall recorded during field experiments did not influenced pest abundance.