Soil insects associated with sugarcane crop in Mato Grosso do Sul, Brazil / Insetos de solo associados à cultura de cana-de-açúcar em Mato Grosso do Sul, Brasil

Pest insects are one of the major factors affecting the productivity of sugarcane, and especially those associated with the soil, which damage the crop if not controlled. There is little information on the insect associated with the soil in the sugarcane crop in the state of Mato Grosso do Sul, Brazil. This study evaluated the occurrence, abundance and population variation of soil-associated insects in sugarcane crops in four counties in the state of Mato Grosso do Sul during a period from September 2009 to August 2010. For the capture of insects, deep in the soil trenches were (50 x 50 x 30 width x length x depth). It was observed that county of Maracaju has a high incidence of soil insects in sugarcane crop. Specimens of the family Scarabaeidae are abundant in sugarcane fields of the state of Mato Grosso do Sul, being Liogenys suturalis the predominant species. Soil insects of the Chrysomelidae family were found with greater abundance in Dourados and Naviraí while Noctuidae, represented only by the Hyponeuma taltula, occurred mainly in Dourados. Insects of the family Termitidae occur in sugarcane fields in the counties of Maracaju and Naviraí but not in Nova Alvorada do Sul and Dourados. Sphenophorus levis and Metamasius hemipterus were alsoreported in the sugarcane fields from Maracaju, being the occurrence these species the first record in the Mato Grosso do Sul State. The determined occurrence of different soil insects in the sugarcane fields may help in their management in the four counties studied.

Os insetos-praga são um dos principais fatores que afetam a produtividade da cana-de-açúcar e, principalmente, aqueles associados ao solo, que prejudicam a cultura se não forem controlados. Existem poucas informações sobre a fauna de insetos associada ao solo na cultura da cana-de-açúcar no estado de Mato Grosso do Sul (MS), Brasil. O objetivo deste estudo foi avaliar a ocorrência, abundância e variação populacional de insetos associados ao solo em lavouras de cana-de-açúcar em quatro municípios do estado de Mato Grosso do Sul durante o período de setembro de 2009 a agosto de 2010. Para a captura de insetos, foram feitas trincheiras (50 cm x 50 cm x 30 cm - largura x comprimento x profundidade) no solo. Observou-se que o município de Maracaju apresenta alta incidência de insetos de solo na cultura da cana-de-açúcar. Exemplares da família Scarabaeidae são abundantes nos canaviais do MS, sendo Liogenys suturalis a espécie predominante. Insetos de solo da família Chrysomelidae foram encontrados com maior abundância em Dourados e Naviraí enquanto Noctuidae, representado apenas por Hyponeuma taltula, ocorreu principalmente em Dourados. Insetos da família Termitidae ocorrem em canaviais nos municípios de Maracaju e Naviraí, mas não em Nova Alvorada do Sul e Dourados. Sphenophorus levis e Metamasius hemipterus (Coleoptera: Curculionidae) também foram encontrados nos canaviais de Maracaju, sendo a ocorrência dessas espécies o primeiro registro no MS. A ocorrência determinada de diferentes insetos de solo nos canaviais auxiliará o manejo nos quatro municípios estudados.

Estimating the relationship of sugarcane borer larvae and crop damage based on adult captures and climate variables

ABSTRACT: Sugarcane borer Diatraea saccharalis (F.) is the primary sugarcane pest in Brazil. To estimate the relationship between larvae in sugarcane stalks and captures of male adults of D. saccharalis, we collected samples weekly: (1) adults with one delta trap with three virgin females and three female pupae and (2) larvae in 120 stalks per plot of 12.6 hectares (355 × 355 m). The study was conducted in two sites with five plots each, in the municipalities of Nova Ponte and Tupaciguara, Minas Gerais State, Brazil, from July 2016 to May 2017. Relationships between (1) males trapped per week and the number of larvae outside of stalks (LOS) were estimated and (2) we evaluated climate variables, namely average temperature, average relative air humidity, hours with relative air humidity below 30 %, rainfall and number of rainy days, and adults and larvae of D. saccharalis. We obtained generalized linear models for LOS in autumn and for larvae inside the stalks (LIS) in spring and autumn and trapped males in both sites. A significant and direct relationship between LIS and males trapped allows predicting larvae density based on captures of males. In addition, plant damage can be estimated based on accumulated captures of males. There was a negative relationship between hours of air humidity < 30 % and larvae outside of stalks. Densities of LIS can be estimated from male captures and by the humidity variables in the trapping week. Nevertheless, the models require validation in the field.

First record of Plectris aliena Chapin, 1934 (Coleoptera: Melolonthidae) as a potential sugarcane pest in Brazil

ABSTRACT: Plectris alienaChapin, 1934, a white grub that promotes serious damage to a variety of crops in North America and Australia, has been reported for the first time in Brazil. Larvae and adults of P. aliena were recorded in sugarcane crops in the state of Mato Grosso do Sul, sampled by trenches in the soil with light traps, respectively, during 2012 and 2013. Root consumption was also determined for the first, second and third instar larvae. The species is univoltine; adults were found mainly in Aug and the peak of third instar larval density was in Apr in all fields sampled. Pupae and adults of P. aliena were observed in the soil profile at depths of up to 60 and 80 cm, respectively. Larvae of P. aliena of the second and third instar consumed the primary and secondary roots of sugarcane, causing serious damage. Third instar larvae consumed 916 mg of root fresh matter, representing 72 % of the sugarcane root system. These results assist in furthering the understanding of its larval dynamics in the soil and provide support for Integrated Pest Management.

First record of Plectris aliena Chapin, 1934 (Coleoptera: Melolonthidae) as a potential sugarcane pest in Brazil

Plectris alienaChapin, 1934, a white grub that promotes serious damage to a variety of crops in North America and Australia, has been reported for the first time in Brazil. Larvae and adults of P. aliena were recorded in sugarcane crops in the state of Mato Grosso do Sul, sampled by trenches in the soil with light traps, respectively, during 2012 and 2013. Root consumption was also determined for the first, second and third instar larvae. The species is univoltine; adults were found mainly in Aug and the peak of third instar larval density was in Apr in all fields sampled. Pupae and adults of P. aliena were observed in the soil profile at depths of up to 60 and 80 cm, respectively. Larvae of P. aliena of the second and third instar consumed the primary and secondary roots of sugarcane, causing serious damage. Third instar larvae consumed 916 mg of root fresh matter, representing 72 % of the sugarcane root system. These results assist in furthering the understanding of its larval dynamics in the soil and provide support for Integrated Pest Management.

Can Trichogramma atopovirilia Oatman & Platner replaces Trichogramma galloi Zucchi for Diatraea saccharalis (Fabricius) control?

Studies on aggressiveness of parasitoids, as assessed by their parasitism against pests, used in biological-control programs are highly important to select the most suitable species and/or strain to control insect pests. The present study investigated whether the egg parasitoid Trichogramma galloi Zucchi, an efficient control agent for sugarcane borer Diatraea saccharalis (Fabricius) in Brazil, could be replaced by Trichogramma atopovirilia Oatman & Platner, a parasitoid easier to mass-produce, since it has been found parasitizing D. saccharalis eggs in the warmest region of Brazil and Argentina. Three strains of the genus Trichogramma were compared: T. atopovirilia (ATP strain) reared on a factitious host Anagasta kuehniella (Zeller); T. atopovirilia isoline ATP-I, reared on D. saccharalis eggs for six generations; and T. galloi, reared on A. kuehniella eggs. We measured parasitism of each strain for 72 h and for the entire life span, parasitism rate per cluster of D. saccharalis eggs, number of parasitoids emerged (parasitism viability), and parasitoid life span. The results confirmed that T. galloi is the best species for D. saccharalis control, showing higher control potential, since parasitism and emergence rate were higher for this species. Although T. atopovirilia ATP-I performed reliably in all parameters, T. galloi exceeded and was the most indicated for mass-rearing in control programs for sugarcane borer.

First record of Plectris aliena Chapin, 1934 (Coleoptera: Melolonthidae) as a potential sugarcane pest in Brazil

Plectris aliena Chapin, 1934, a white grub that promotes serious damage to a variety of crops in North America and Australia, has been reported for the first time in Brazil. Larvae and adults of P. aliena were recorded in sugarcane crops in the state of Mato Grosso do Sul, sampled by trenches in the soil with light traps, respectively, during 2012 and 2013. Root consumption was also determined for the first, second and third instar larvae. The species is univoltine; adults were found mainly in Aug and the peak of third instar larval density was in Apr in all fields sampled. Pupae and adults of P. aliena were observed in the soil profile at depths of up to 60 and 80 cm, respectively. Larvae of P. aliena of the second and third instar consumed the primary and secondary roots of sugarcane, causing serious damage. Third instar larvae consumed 916 mg of root fresh matter, representing 72 % of the sugarcane root system. These results assist in furthering the understanding of its larval dynamics in the soil and provide support for Integrated Pest Management.

Resistance of sorghum hybrids to sorghum aphid / Resistência de híbridos de sorgo ao pulgão do sorgo

The aphid Melanaphis sorghi (Theobald) (Hemiptera: Aphididae), which infest the sorghum crop, has been an economically important pest which have been causing severe damage to sorghum crops in Brazil since 2019. These species have been observed mainly at the end of vegetative stage and beginning of reproductive stage of plants. Their high reproductive rate on sorghum raises concerns about these pests. Therefore, the present study aimed to estimate the life expectancy and fertility tables of Melanaphis sorghi fed on 15 hybrids of grain sorghum, in order to know the resistance characteristics of these materials and understand how plant resistance can help manage this insect. This study was carried out in a laboratory at 26±2 ºC and 60±10% R.H (relative humidity). Fifty insects were kept in each hybrid, each insect was considered one repetition. According to biological parameters and fertility life table, hybrids BRS373, DKB590 and 50A10 were less suitable for the sugarcane aphid multiplication. Thus, these hybrids could be useful to manage this pest, since the population growth speed is one of the worst problems for the implementation of cropping systems. Genotypes AG1090, MSK327 and XGN1305 favored the development of this pest and, when chosen within a cropping system, other management strategies should be considered.

O pulgão Melanaphis sorghi (Theobald) (Hemiptera: Aphididae), que infesta a cultura do sorgo, tem sido uma praga economicamente importante que vem causando sérios danos às lavouras de sorgo no Brasil desde 2019. As infestações têm sido observadas principalmente no final do estádio vegetativo e início do período reprodutivo das plantas. A alta taxa de reprodução destes insetos no sorgo aumenta a preocupação com a praga. Nesse sentido, o presente estudo teve por objetivo estimar as tabelas de esperança de vida e fertilidade para Melanaphis sorghi, alimentados com quinze híbridos de sorgo granífero, afim de conhecer as características de resistência desses materiais e entender como a resistência de plantas pode ajudar no manejo do inseto. O estudo foi conduzido em laboratório com temperatura de 26±2ºC e UR (Umidade Relativa) de 60±10%, foram mantidos 50 insetos em cada hibrido, cada inseto, considerado uma repetição. Com as estimativas dos parâmetros biológicos e mediante tabela de vida de fertilidade, verificamos que os híbridos BRS373, DKB590 e 50A10 foram menos adequados para a multiplicação da praga o que poderia ser considerado melhor para uso em sistemas de manejo da praga, uma vez que a velocidade de crescimento populacional pode ser vista como um dos piores problemas para implementação do sistema de manejo. Os genótipos AG1090, MSK327 e XGN1305 favoreceram o desenvolvimento da praga e, ao ser escolhido dentro do sistema de produção devem ser considerados outras estratégias de manejo.

Tolerance of sugarcane cultivars to Mahanarva fimbriolata / Tolerância de cultivares de cana-de-açúcar a Mahanarva fimbriolata

Mahanarva fimbriolata (Stål) (Hemiptera: Cercopidae), the sugarcane spittlebug, is one of the most important pests of this crop in Brazil. The magnitude of its damage depends on the pest population, the plants size when they are infested and the cultivar tolerance. The knowledge about those parameters allows the elaboration of the spittlebug management matrix, in which small plants and less tolerant varieties fields are prioritized for sampling and controlling in relation to developed plants and tolerant varieties fields. Therefore, this study aimed to evaluate the response of sugarcane genotypes to M. fimbriolata, so that they can be correctly allocated in the management matrix. Two experiments were carried out under laboratory conditions using a randomized block design with treatments in a factorial arrangement of 2×11 (experiment 1) and 2×21 (experiment 2), with six (experiment 1) or five replicates (experiment 2). The first factor included two levels of infestation (infested and noninfested plants with spittlebugs), while the second consisted of the cultivars. Cultivars IACSP01-5503, CTC 9004 and RB925211 were considered tolerant to spittlebug, they did not show significant reductions in aboveground biomass, despite showing symptoms of pest attack, as leaves yellowing, while CV6654 and IACSP01-3127 were the least tolerant cultivars, showing the highest reduction in aboveground biomass due to M. fimbriolata infestation. Thus, CV6654 and IACSP01-3127 should be prioritized for sampling and control over the others. On average, spittlebug infestations caused 30.9 % of reduction of aboveground biomass.

A cigarrinha das raízes, Mahanarva fimbriolata (Stål) (Hemiptera: Cercopidae), é uma das mais importantes pragas da cana-de-açúcar no Brasil. A grandeza de seus danos depende da população, do tamanho da planta ao sofrer o ataque e da tolerância da cultivar. O conhecimento sobre esses parâmetros permite a elaboração da matriz de manejo de cigarrinha das raízes, na qual canaviais de plantas pouco desenvolvidas e cultivares não tolerantes são priorizados para amostragem e controle em relação a canaviais de plantas mais desenvolvidas e variedades tolerantes. Portanto, o objetivo do presente trabalho foi avaliar a reação de cultivares de cana-de-açúcar à M. fimbriolata, para que elas possam ser adequadamente locadas na matriz de manejo. Dois experimentos foram conduzidos em condições de laboratório, usando o delineamento de blocos casualizados com seis (experimento 1) ou cinco (experimento 2) repetições e tratamentos em arranjo fatorial 2×11 (experimento 1) e 2×21 (experimento 2). O primeiro fator foi representado pelos dois níveis de infestação de cigarrinha (infestado e não infestado), enquanto o segundo, pelas cultivares em estudo. As cultivares IACSP01-5503, CTC 9004 e RB925211 foram consideradas tolerantes a M. fimbriolata, visto que a praga não causou redução significativa da massa verde da parte aérea, apesar de ter provocado alguns sintomas de ataque, como amarelecimento de folhas, enquanto CV6654 e IACSP01-3127 foram as cultivares menos tolerantes, pois mostraram as mais altas reduções na massa verde da parte aérea das plantas. Assim, CV6654 e IACSP01-3127 deveriam ser priorizadas na amostragem e controle em relação às demais. Na média, a cigarrinha das raízes provocou 30,9 % de redução na massa verde da parte aérea das plantas.

Histopathological changes in Lithobates catesbeianustadpoles used as biomarkers of pesticide poisoning / Alterações histopatológicas utilizadas em girinos de Lithobates catesbeianuscomo biomarcadores de intoxicações causadas por pesticidas

The use of biological indicators has increased in recent years with the aim of investigating environ-mental pollution in aquatic environments that are vulnerable to the constant use of pesticides. Some biomarkers can help assess the health status, indicating physical, metabolic, and behavioral changes under acute and sublethal poisoning. The mixture of the active ingredients cyproconazole and pico-xystrobin is a widely used fungicide for the control of pests in cotton, rice, coffee, sugarcane, corn, soybean, and wheat. The objective of this study was to verify the occurrence of possible histopatholo-gical lesions in the liver and kidneys of bullfrog tadpoles (Lithobates catesbeianus) caused by a fungi-cide commercial formula composed of picoxystrobin and cyproconazole. The animals were subjected to different concentrations of the fungicide to determine the median lethal concentration (LC50-96h = 0.05 mg L-1), that is, the lethal dose for 50% of the animals in 96 h. After determining the value of LC50-96h, the animals were subjected to three sublethal concentrations (LC50-96h/2, LC50-96h/10, and LC-50-96h/100). Through histological biomarkers, it was verified that this fungicide changed the morphology of the animals' kidney and liver tissues in a chronic way, impairing the functioning of organs that are essential for their survival and metamorphosis, which can result in an imbalance in the biodiversity of aquatic ecosystems.(AU)

O uso de indicadores biológicos tem aumentado nos últimos anos, com o intuito de investigar a po-luição ambiental em ambientes aquáticos que são vulneráveis ao constante uso de pesticidas. Alguns biomarcadores podem ajudar a avaliar o estado de saúde, indicando alterações físicas, metabólicas e comportamentais de intoxicações agudas e subletais. A mistura dos ingredientes ativos picoxistrobina e ciproconazol é amplamente usada como fungicida para o controle de pragas da cultura de algodão, arroz, café, cana-de-açúcar, milho, soja e trigo. O objetivo deste trabalho foi verificar a ocorrência de possíveis lesões histopatológicas em fígado e rins de girinos de rã-touro (Lithobates catesbeianus) causadas pela mistura dos fungicidas picoxistrobina e ciproconazol. Os animais foram submetidos a diferentes concentrações do fungicida para determinação da concentração letal mediana (CL50-96h = 0,05 mg L-1), ou seja, a dose letal para 50% dos animais em 96 horas. Após a determinação do valor da CL50-96h, os animais foram submetidos a três concentrações subletais (CL50-96h/2, CL50-96h/10 e CL50-96h/100). Através dos biomarcadores histológicos, a pesquisa verificou que esse fungicida alterou a morfolo-gia dos tecidos renais e hepáticos dos animais de maneira crônica, prejudicando o funcionamento de órgãos que são fundamentais para sua sobrevivência e metamorfose, o que pode resultar em um desequilíbrio para a biodiversidade dos ecossistemas aquáticos.(AU)

Sugarcane froghoppers in northeast Brazil / Cigarrinhas da cana-de-açúcar no nordeste brasileiro

Froghoppers (Mahanarva spp.) are pests of great economic importance for various regions of Brazil. Many species have a variation in the alar pattern, a parameter that often leads to incorrect identification. We collected froghopper adults in sugarcane fields in the municipalities of Murici and Maceió, in Alagoas, Lagoa de Itaenga and Camutanga, in Pernambuco, São Raimundo das Mangabeiras, in Maranhão, and União and Boa Hora, in the Teresina microregion in Piauí. The froghoppers were assembled and identified and are representatives of three species: M. spectabilis, M. fimbriolata, and M. posticata. This is the first record of M. spectabilis attacking sugarcane fields in the states of Piauí and Maranhão, Brazil. We found the species M. posticata and M. fimbriolata in the sugarcane fields of Alagoas and only M. posticata in Pernambuco.(AU)

As cigarrinhas (Mahanarva spp.) são pragas de grande importância econômica em várias regiões do país. Muitas espécies têm variação no padrão alar, parâmetro que leva muitas vezes à identificação de forma incorreta. Adultos de cigarrinhas foram coletados em canaviais nos municípios de Murici e Maceió em Alagoas, Lagoa de Itaenga e Camutanga em Pernambuco, São Raimundo das Mangabeiras em Maranhão e União e Boa Hora, microrregião de Teresina em Piauí, e foram montados e identificados. As cigarrinhas coletadas são representantes de três espécies M. spectabilis, M. fimbriolata e M. posticata, sendo este o primeiro registro da espécie M. spectabilis atacando canaviais nos estados do Piauí e Maranhão. Em canaviais de Alagoas, foram encontradas as espécies M. posticata e M. fimbriolata e, em Pernambuco, apenas M. posticata.(AU)

Sugarcane froghoppers in northeast Brazil / Cigarrinhas da cana-de-açúcar no nordeste brasileiro

Froghoppers (Mahanarva spp.) are pests of great economic importance for various regions of Brazil. Many species have a variation in the alar pattern, a parameter that often leads to incorrect identification. We collected froghopper adults in sugarcane fields in the municipalities of Murici and Maceió, in Alagoas, Lagoa de Itaenga and Camutanga, in Pernambuco, São Raimundo das Mangabeiras, in Maranhão, and União and Boa Hora, in the Teresina microregion in Piauí. The froghoppers were assembled and identified and are representatives of three species: M. spectabilis, M. fimbriolata, and M. posticata. This is the first record of M. spectabilis attacking sugarcane fields in the states of Piauí and Maranhão, Brazil. We found the species M. posticata and M. fimbriolata in the sugarcane fields of Alagoas and only M. posticata in Pernambuco.(AU)

As cigarrinhas (Mahanarva spp.) são pragas de grande importância econômica em várias regiões do país. Muitas espécies têm variação no padrão alar, parâmetro que leva muitas vezes à identificação de forma incorreta. Adultos de cigarrinhas foram coletados em canaviais nos municípios de Murici e Maceió em Alagoas, Lagoa de Itaenga e Camutanga em Pernambuco, São Raimundo das Mangabeiras em Maranhão e União e Boa Hora, microrregião de Teresina em Piauí, e foram montados e identificados. As cigarrinhas coletadas são representantes de três espécies M. spectabilis, M. fimbriolata e M. posticata, sendo este o primeiro registro da espécie M. spectabilis atacando canaviais nos estados do Piauí e Maranhão. Em canaviais de Alagoas, foram encontradas as espécies M. posticata e M. fimbriolata e, em Pernambuco, apenas M. posticata.(AU)

Performance of insecticides in control of Diatraea saccharalis (Lepidoptera: Crambidae) in sugarcane / Desempenho de inseticidas no controle de Diatraea saccharalis (Lepidoptera: Crambidae) em cana-de-açúcar

The population of the caterpillar Diatraea saccharalis (Lepidoptera: Crambidae) has increased in the crop of sugarcane in recent years. Although the control of this insect is traditionally carried out through biological control, the use of phytosanitary products has still been necessary. Therefore, the goal of this work was to evaluate the performance of different insecticides in sugarcane borer control, as well as the effect on productivity and total recoverable sugar (TRS). The experiment was conducted in a randomized experimental delineation of blocks, with six treatments and four blocks. Treatments consisted of five insecticides and one control group (without application of insecticide). For calculating the D. saccharalis infestation index, monthly samplings were performed every 30 days, for 12 months. After this period, the final D. saccharalis infestation index was evaluated and calculated for each treatment. In order to compare productivity among procedures, four central lines were collected from each plot. Thus, the samples were weighed for the productivity calculation (TCH) and sent to the laboratory for the total recoverable sugar (TRS) analysis. The chloranthraniliprole (350) insecticide provided a lower index of sugarcane borer infestation, in addition to greater productivity when compared to the other insecticides. There was no significant difference in the parameter of total recoverable sugar (TRS) among treatments.(AU)

A população da lagarta Diatraea saccharalis (Lepidoptera: Crambidae) tem aumentado na cultura de cana-de-açúcar nos últimos anos. Apesar do controle deste inseto ser tradicionalmente realizado através do controle biológico, o uso de produtos fitossanitários ainda tem sido necessário. Portanto, o objetivo deste trabalho foi avaliar o desempenho de diferentes inseticidas no controle da broca da cana-de-açúcar, bem como o efeito sobre a produtividade e o açúcar total recuperável (ATR). O experimento foi conduzido no delineamento experimental de blocos ao acaso, com seis tratamentos e quatro blocos. Os tratamentos foram compostos por cinco inseticidas e um tratamento sem aplicação de inseticida. Para o cálculo do índice de infestação da D. saccharalis foram realizadas amostragens mensais a cada 30 dias, durante 12 meses. Após esse período, foi avaliado e calculado o índice de infestação final da D. saccharalis de cada tratamento. Para comparar a produtividade entre os tratamentos, foram colhidas as quatro linhas centrais de cada parcela. Assim, as amostras foram pesadas para o cálculo da produtividade (TCH) e enviadas ao laboratório para análise do açúcar total recuperável (ATR). O inseticida clorantraniliprole (350) proporcionou um menor índice de infestação da broca da cana, além de maior produtividade, em relação aos demais inseticidas. Não houve diferença significativa do parâmetro de açúcar total recuperável (ATR) entre os tratamentos.(AU)

Performance of insecticides in control of Diatraea saccharalis (Lepidoptera: Crambidae) in sugarcane / Desempenho de inseticidas no controle de Diatraea saccharalis (Lepidoptera: Crambidae) em cana-de-açúcar

The population of the caterpillar Diatraea saccharalis (Lepidoptera: Crambidae) has increased in the crop of sugarcane in recent years. Although the control of this insect is traditionally carried out through biological control, the use of phytosanitary products has still been necessary. Therefore, the goal of this work was to evaluate the performance of different insecticides in sugarcane borer control, as well as the effect on productivity and total recoverable sugar (TRS). The experiment was conducted in a randomized experimental delineation of blocks, with six treatments and four blocks. Treatments consisted of five insecticides and one control group (without application of insecticide). For calculating the D. saccharalis infestation index, monthly samplings were performed every 30 days, for 12 months. After this period, the final D. saccharalis infestation index was evaluated and calculated for each treatment. In order to compare productivity among procedures, four central lines were collected from each plot. Thus, the samples were weighed for the productivity calculation (TCH) and sent to the laboratory for the total recoverable sugar (TRS) analysis. The chloranthraniliprole (350) insecticide provided a lower index of sugarcane borer infestation, in addition to greater productivity when compared to the other insecticides. There was no significant difference in the parameter of total recoverable sugar (TRS) among treatments.(AU)

A população da lagarta Diatraea saccharalis (Lepidoptera: Crambidae) tem aumentado na cultura de cana-de-açúcar nos últimos anos. Apesar do controle deste inseto ser tradicionalmente realizado através do controle biológico, o uso de produtos fitossanitários ainda tem sido necessário. Portanto, o objetivo deste trabalho foi avaliar o desempenho de diferentes inseticidas no controle da broca da cana-de-açúcar, bem como o efeito sobre a produtividade e o açúcar total recuperável (ATR). O experimento foi conduzido no delineamento experimental de blocos ao acaso, com seis tratamentos e quatro blocos. Os tratamentos foram compostos por cinco inseticidas e um tratamento sem aplicação de inseticida. Para o cálculo do índice de infestação da D. saccharalis foram realizadas amostragens mensais a cada 30 dias, durante 12 meses. Após esse período, foi avaliado e calculado o índice de infestação final da D. saccharalis de cada tratamento. Para comparar a produtividade entre os tratamentos, foram colhidas as quatro linhas centrais de cada parcela. Assim, as amostras foram pesadas para o cálculo da produtividade (TCH) e enviadas ao laboratório para análise do açúcar total recuperável (ATR). O inseticida clorantraniliprole (350) proporcionou um menor índice de infestação da broca da cana, além de maior produtividade, em relação aos demais inseticidas. Não houve diferença significativa do parâmetro de açúcar total recuperável (ATR) entre os tratamentos.(AU)

Yield and technological quality of sugarcane cultivars under infestation of Diatraea saccharalis (Fabr, 1794) / Produtividade e qualidade tecnológica de cultivares de cana-de-açúcar sob infestação de Diatraea saccharalis (Fabr, 1794)

The sugarcane borer, Diatraea saccharalis (Fabr., 1794) (Lepidoptera: Crambidae), is one of the main pests of sugarcane. This pest can reduce the quality and yield of the crop. Information on the quality and yield of cultivars in relation to the attack of sugarcane borer are necessary, since they guide the choice of the best materials for use in joint with other management tactics. Two field experiments were conducted in 2011 and 2012 to compare the quality and yield of 16 commercial sugarcane cultivars (IACSP93-3046, IACSP94-2094, IACSP94-2101, IAC91-1099, IACSP95-5000, IAC87-3396, RB92579, RB867515, RB966928, CTC2, CTC4, CTC9, CTC11, CTC15, CTC18 and SP86-0042) relative to the natural infestation of D. saccharalis. The experimental design was a randomized complete block with four replications. There was no difference between treatments for infestation index, with averages of 1.2 to 8.7% of bored internodes. Higher percentages of internodes with red rot were observed for CTC9, CTC2 and RB966928. The cultivars CTC4 and RB92579 infested with D. saccharalis resulted in lower technological quality, due the reduction in the contents of brix, apparent sucrose content (POL) and purity; and increase of the reducing sugars and, consequently, lower theoretically recoverable sugar (TRS). On the other hand, the lowest yields (t of cane ha-1) were observed for CTC18, IACSP94-2094, IACSP94-2101 and RB966928. Therefore, according to the hierarchical cluster analysis (UPGMA), the cultivars RB867515, CTC11, IAC91-1099, CTC15, SP86-0042, CTC2 and IACSP94-3046 were resistant to D. saccharalis.(AU)

A broca-da-cana, Diatraea saccharalis (Fabr., 1794) (Lepidoptera: Crambidae), é uma das principais pragas da cana-de-açúcar. Essa praga pode reduzir a qualidade e a produtividade da cultura. Informações sobre a qualidade e a produtividade de cultivares em relação ao ataque da broca-da-cana são necessárias, pois orientam a escolha dos melhores materiais para utilização em conjunto com outras táticas de manejo. Dois experimentos de campo foram instalados em 2011 e 2012 para comparar a qualidade e a produtividade de 16 cultivares comerciais de cana-de-açúcar (IACSP93-3046, IACSP94-2094, IACSP94-2101, IAC91-1099, IACSP95-5000, IAC87-3396, RB92579, RB867515, RB966928, CTC2, CTC4, CTC9, CTC11, CTC15, CTC18 e SP86-0042) em relação à infestação natural de D. saccharalis. O delineamento dos experimentos foi em blocos completos ao acaso, com quatro repetições. Não houve diferença entre os tratamentos para a intensidade de infestação, com médias de 1,2 a 8,7% de entrenós brocados. Maiores porcentagens de entrenós com podridão-vermelha foram observadas para CTC9, CTC2 e RB966928. Os cultivares CTC4 e RB92579 infestados com D. saccharalis resultaram em menor qualidade tecnológica, por causa da redução nos teores de brix, teor de sacarose aparente (POL) e pureza; e aumento dos açúcares redutores e, consequentemente, menor quantidade de açúcar teoricamente recuperável (ATR). Por outro lado, as menores produtividades (t de cana ha-1) foram observadas para CTC18, IACSP94-2094, IACSP94-2101 e RB966928. Portanto, de acordo com a análise hierárquica de agrupamento (UPGMA), os cultivares RB867515, CTC11, IAC91-1099, CTC15, SP86-0042, CTC2 e IACSP94-3046 mostraram-se resistentes a D. saccharalis.(AU)

Yield and technological quality of sugarcane cultivars under infestation of Diatraea saccharalis (Fabr, 1794) / Produtividade e qualidade tecnológica de cultivares de cana-de-açúcar sob infestação de Diatraea saccharalis (Fabr, 1794)

The sugarcane borer, Diatraea saccharalis (Fabr., 1794) (Lepidoptera: Crambidae), is one of the main pests of sugarcane. This pest can reduce the quality and yield of the crop. Information on the quality and yield of cultivars in relation to the attack of sugarcane borer are necessary, since they guide the choice of the best materials for use in joint with other management tactics. Two field experiments were conducted in 2011 and 2012 to compare the quality and yield of 16 commercial sugarcane cultivars (IACSP93-3046, IACSP94-2094, IACSP94-2101, IAC91-1099, IACSP95-5000, IAC87-3396, RB92579, RB867515, RB966928, CTC2, CTC4, CTC9, CTC11, CTC15, CTC18 and SP86-0042) relative to the natural infestation of D. saccharalis. The experimental design was a randomized complete block with four replications. There was no difference between treatments for infestation index, with averages of 1.2 to 8.7% of bored internodes. Higher percentages of internodes with red rot were observed for CTC9, CTC2 and RB966928. The cultivars CTC4 and RB92579 infested with D. saccharalis resulted in lower technological quality, due the reduction in the contents of brix, apparent sucrose content (POL) and purity; and increase of the reducing sugars and, consequently, lower theoretically recoverable sugar (TRS). On the other hand, the lowest yields (t of cane ha-1) were observed for CTC18, IACSP94-2094, IACSP94-2101 and RB966928. Therefore, according to the hierarchical cluster analysis (UPGMA), the cultivars RB867515, CTC11, IAC91-1099, CTC15, SP86-0042, CTC2 and IACSP94-3046 were resistant to D. saccharalis.(AU)

A broca-da-cana, Diatraea saccharalis (Fabr., 1794) (Lepidoptera: Crambidae), é uma das principais pragas da cana-de-açúcar. Essa praga pode reduzir a qualidade e a produtividade da cultura. Informações sobre a qualidade e a produtividade de cultivares em relação ao ataque da broca-da-cana são necessárias, pois orientam a escolha dos melhores materiais para utilização em conjunto com outras táticas de manejo. Dois experimentos de campo foram instalados em 2011 e 2012 para comparar a qualidade e a produtividade de 16 cultivares comerciais de cana-de-açúcar (IACSP93-3046, IACSP94-2094, IACSP94-2101, IAC91-1099, IACSP95-5000, IAC87-3396, RB92579, RB867515, RB966928, CTC2, CTC4, CTC9, CTC11, CTC15, CTC18 e SP86-0042) em relação à infestação natural de D. saccharalis. O delineamento dos experimentos foi em blocos completos ao acaso, com quatro repetições. Não houve diferença entre os tratamentos para a intensidade de infestação, com médias de 1,2 a 8,7% de entrenós brocados. Maiores porcentagens de entrenós com podridão-vermelha foram observadas para CTC9, CTC2 e RB966928. Os cultivares CTC4 e RB92579 infestados com D. saccharalis resultaram em menor qualidade tecnológica, por causa da redução nos teores de brix, teor de sacarose aparente (POL) e pureza; e aumento dos açúcares redutores e, consequentemente, menor quantidade de açúcar teoricamente recuperável (ATR). Por outro lado, as menores produtividades (t de cana ha-1) foram observadas para CTC18, IACSP94-2094, IACSP94-2101 e RB966928. Portanto, de acordo com a análise hierárquica de agrupamento (UPGMA), os cultivares RB867515, CTC11, IAC91-1099, CTC15, SP86-0042, CTC2 e IACSP94-3046 mostraram-se resistentes a D. saccharalis.(AU)

Crop residue harvest for bioenergy production and its implications on soil functioning and plant growth: A review

The use of crop residues as a bioenergy feedstock is considered a potential strategy to mitigate greenhouse gas (GHG) emissions. However, indiscriminate harvesting of crop residues can induce deleterious effects on soil functioning, plant growth and other ecosystem services. Here, we have summarized the information available in the literature to identify and discuss the main trade-offs and synergisms involved in crop residue management for bioenergy production. The data consistently showed that crop residue harvest and the consequent lower input of organic matter into the soil led to C storage depletions over time, reducing cycling, supply and availability of soil nutrients, directly affecting the soil biota. Although the biota regulates key functions in the soil, crop residue can also cause proliferation of some important agricultural pests. In addition, crop residues act as physical barriers that protect the soil against raindrop impact and temperature variations. Therefore, intensive crop residue harvest can cause soil structure degradation, leading to soil compaction and increased risks of erosion. With regard to GHG emissions, there is no consensus about the potential impact of management of crop residue harvest. In general, residue harvest decreases CO2 and N2O emissions from the decomposition process, but it has no significant effect on CH4 emissions. Plant growth responses to soil and microclimate changes due to crop residue harvest are site and crop specific. Adoption of the best management practices can mitigate the adverse impacts of crop residue harvest. Longterm experiments within strategic production regions are essential to understand and monitor the impact of integrated agricultural systems and propose customized solutions for sustainable crop residue management in each region or landscape. Furthermore, private and public investments/cooperations are necessary for a better understanding of the potential environmental...

Crop residue harvest for bioenergy production and its implications on soil functioning and plant growth: A review

The use of crop residues as a bioenergy feedstock is considered a potential strategy to mitigate greenhouse gas (GHG) emissions. However, indiscriminate harvesting of crop residues can induce deleterious effects on soil functioning, plant growth and other ecosystem services. Here, we have summarized the information available in the literature to identify and discuss the main trade-offs and synergisms involved in crop residue management for bioenergy production. The data consistently showed that crop residue harvest and the consequent lower input of organic matter into the soil led to C storage depletions over time, reducing cycling, supply and availability of soil nutrients, directly affecting the soil biota. Although the biota regulates key functions in the soil, crop residue can also cause proliferation of some important agricultural pests. In addition, crop residues act as physical barriers that protect the soil against raindrop impact and temperature variations. Therefore, intensive crop residue harvest can cause soil structure degradation, leading to soil compaction and increased risks of erosion. With regard to GHG emissions, there is no consensus about the potential impact of management of crop residue harvest. In general, residue harvest decreases CO2 and N2O emissions from the decomposition process, but it has no significant effect on CH4 emissions. Plant growth responses to soil and microclimate changes due to crop residue harvest are site and crop specific. Adoption of the best management practices can mitigate the adverse impacts of crop residue harvest. Longterm experiments within strategic production regions are essential to understand and monitor the impact of integrated agricultural systems and propose customized solutions for sustainable crop residue management in each region or landscape. Furthermore, private and public investments/cooperations are necessary for a better understanding of the potential environmental...(AU)

Jaburetox: update on a urease-derived peptide

Abstract Urease from Canavalia ensiformis seeds was the first enzyme ever to be crystallized, in 1926. These proteins, found in plants, bacteria and fungi, present different biological properties including catalytic hydrolysis of urea, and also enzyme-independent activities, such as induction of exocytosis, pro-inflammatory effects, neurotoxicity, antifungal and insecticidal properties. Urease is toxic to insects and fungi per se but part of this toxicity relies on an internal peptide (~11 kDa), which is released upon digestion of the protein by insect enzymes. A recombinant form of this peptide, called jaburetox (JBTX), was constructed using jburell gene as a template. The peptide exhibits liposome disruption properties, and insecticidal and fungicidal activities. Here we review the known biological properties activities of JBTX, and comment on new ones not yet fully characterized. JBTX was able to cause mortality of Aedes aegypti larvae in a feeding assay whereas in a dose as low as of 0.1 g it provoked death of Triatoma infestans bugs. JBTX (105-106 M) inhibits the growth of E. coli, P. aeruginosa and B. cereus after 24 h incubation. Multilamellar liposomes interacting with JBTX undergo reorganization of the membrane's lipids as detected by small angle X-ray scattering (SAXS) studies. Encapsulating JBTX into lipid nanoparticles led to an increase of the peptide's antifungal activity. Transgenic tobacco and sugarcane plants expressing the insecticidal peptide JBTX, showed increased resistance to attack of the insect pests Spodoptera frugiperda, Diatraea saccharalis and Telchin licus licus. Many questions remain unanswered; however, so far, JBTX has shown to be a versatile peptide that can be used against various insect and fungus species, and in new bacterial control strategies.