The sugarcane borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), is a key pest of sugarcane (Saccharum spp.). While damage caused by this pest has increased in the past 20 yr, studies investigating the insect–plant interactions are still lacking. Moreover, there is no information about the consequences of borer damage on the parameters of sugar quality. Therefore, two field experiments were performed during the 2010 and 2011 growing seasons in Brazil to compare the raw material and sugar quality of SP80‐3280 sugarcane plants with and without the sugarcane borer. Plants were protected within screen cages and infested weekly during the 2010 and 2011 seasons, using egg masses starting at the second and third internode stage. At harvest, 25.77 and 19.01% of the internodes were bored by larvae (infestation intensity, II) in the first and second seasons, respectively. There was no correlation between the borer gallery total volume and II. The fiber content significantly increased with increasing II. The stalk biometric parameters, such as length, diameter, and yield, were not correlated with II. The sucrose yield significantly decreased with increasing II. Consequently, sugar yield losses were estimated at 8.83 and 19.80% per 1% bored internode for the first and second seasons, respectively. The concentration of phenolic compounds increased, and unclarified juice color quality decreased, with increasing II. Significant differences were detected in the quality of the sugar. These results should be confirmed for other sugarcane cultivars and incorporated into an economic injury level to enhance decision‐making strategies for borer management.

-The objective of this work was to evaluate the impacts of spittlebug (Mahanarva fimbriolata) attack on sugarcane quality and ethanol production. Technological and microbiological parameters of juice and fermentation process were evaluated in ten fermentation cycles and two harvest seasons. Treatments consisted of different spittlebug stalk damage levels: control, with 100% of apparently healthy stalks; medium, with 15% of damaged or dry stalks (DDS); high, with 30% of DDS; and very high, with 60% of DDS. Spittlebug attack caused significant losses in cane quality, reducing total soluble solids, sucrose content, total reducing sugars, and pH, and increasing total phenolic compounds, and total and volatile juice acidity. The fermentation process was also significantly affected, resulting in lower ethanol content in wine. There was an increase in acetaldehyde concentration in the distillate. The spittlebug attack caused negative impacts on sugarcane quality and fermentation process, and these impacts are stronger in late season harvests.Index terms: Mahanarva fimbriolata, Saccharum, cane quality, ethanolic fermentation, technological quality. Impacto da cigarrinha-das-raízes na qualidade da cana-de-açúcar e na produção de etanolResumo -O objetivo deste trabalho foi avaliar o impacto do ataque da cigarrinha-das-raízes (Mahanarva fimbriolata) na qualidade da cana-de-açúcar e na produção de etanol. Os parâmetros tecnológicos e microbiológicos do caldo e do processo fermentativo foram avaliados em dez ciclos de fermentação e duas épocas de colheita. Os tratamentos consistiram de diferentes níveis de danos da cigarrinha nos colmos: testemunha, com 100% de colmos aparentemente sadios; médio, com 15% de dano ou colmos secos (DCS); alto, com 30% de DCS; e muito alto, com 60% de DCS. O ataque da praga causou significativa redução na qualidade da cana, ao diminuir teores de sólidos solúveis, teores de sacarose, açúcares redutores totais e pH, e aumentar os compostos fenólicos e a acidez total e volátil do caldo. O processo fermentativo também foi significativamente afetado, o que resultou em vinhos com menores teores alcoólicos. Houve aumento na concentração de acetaldeído no destilado. O ataque da cigarrinha-das-raízes causou impactos negativos na qualidade da cana-de-áçucar e no processo fermentativo, e esses impactos são maiores nas colheitas de final de temporada.Termos para indexação: Mahanarva fimbriolata, Saccharum, qualidade da cana, fermentação etanólica, qualidade tecnológica.

Neotropical Entomology 37(1): 068-073 (2008) Infl uência da Injúria de Mahanarva fi mbriolata (Stål) (Hemiptera: Cercopidae) na Qualidade do Caldo de Cana RESUMO -Mahanarva fi mbriolata (Stål) é considerada praga importante na América Latina por reduzir a produtividade de cana-de-açúcar. Há pouca informação sobre o efeito do inseto na qualidade da cana que será utilizada para produção de açúcar e álcool. Assim, objetivou-se avaliar a qualidade do caldo da cana de plantas atacadas pela cigarrinha-das-raízes. Adotou-se o delineamento experimental inteiramente casualizado com 15 repetições e dois tratamentos: testemunha e controle químico com tiametoxam. Nas parcelas experimentais foram encontradas em média 9,2 ± 4,44 ninfas m -1 em monitoramento inicial (dezembro/2003). As ninfas foram contadas aos 18, 35, 55, e 82 dias após a primeira contagem, sendo a infestação expressa em insetos-dia acumulados. Em julho de 2004, procedeu-se à colheita de colmos e extração do caldo, analisando-se o Brix, Pol, açúcares redutores, pH, fi bra, pureza, açúcares redutores totais, dextrana, amido, compostos fenólicos totais e produtividade. O controle químico reduziu a população do inseto e elevou a produtividade de colmos e do pH do caldo. A infestação acumulada foi correlacionada signifi cativa e negativamente com a produtividade, Pol, pH, e pureza. O teor de compostos fenólicos aumentou com a elevação da infestação, enquanto que os valores de dextrana e amido não foram alterados. Infestações de 2,4 e 7,3 ninfas m -1 dia -1 causaram reduções da ordem de 8,3% e 29,8% na produtividade; 1,9 e 5,8% na Pol; 0,4% e 1,1% no pH e 0,4% e 1,2% na pureza, respectivamente, em comparação com áreas de população baixa (< 0,1 ninfa m -1 ).PALAVRAS-CHAVE: Cigarrinha-das-raízes, inseto-dia, controle químico ABSTRACT -Mahanarva fi mbriolata (Stål) is an important pest in Latin America and causes signifi cant reduction in sugarcane productivity. There is no information regarding the effect of this pest on the quality of cane juice used for sugar and alcohol production. This work aimed at evaluating the quality of sugarcane juice from plants attacked by spittlebugs. The experiment was arranged in a completely randomized design with 15 replications, and comprised two treatments: control and chemical treatment with thiamethoxam. An average of 9.2 ± 4.44 spittlebug nymphs m -1 were found in the plots prior to insecticide application. Nymphs were counted 18, 35, 55, and 82 days after the initial sampling (december/2003). During the mid growing season (July 2004), the juice was extracted from stalks and analyzed for Brix, Pol, RS, pH, fi ber, purity, TRS, dextran, starch, and total phenolic compounds. Stalk yield was also measured. Chemical treatment was effi cient in reducing spittlebug population, and elevated both stalk yield and juice pH. The accumulated infestation expressed as insect-days was signifi cantly and negatively correlated to yield, Pol, pH, and purity. The concentration of phenolic compounds increased with pest infestation, while dextra...

The spittlebug (Mahanarva fimbriolata) has become a key pest of the sugarcane crop in Brazil with the increase of green-cane harvesting, causing stalk yield and cane quality losses. This research was undertaken to evaluate the effects of the spittlebug (Mahanarva fimbriolata) on cane quality and juice fermentation. The experiment was arranged in a completely randomized 5 × 2 factorial design, with five spittlebug infestation levels (0-0.5; 0.6-2.5; 2.6-5; 5.1-8; 8.1-12.5 nymphs m . Microbiological analyses were performed at the beginning, middle and end of the fermentation process. The alcohol content and total residual reducing sugars were measured in the wine. Spittlebug attack influenced negatively sugarcane quality, yeast cell and bud viability, and wine alcohol content. Insecticide application resulted in higher cane quality and cell and bud viabilities, resulting in increased fermentation yield. Key words: Saccharum spp., Mahanarva fimbriolata, fermentation process, ethanol production A INFESTAÇÃO DE CIGARRINHA-DAS-RAÍZES EM CANA-DE-AÇÚCAR AFETA A FERMENTAÇÃO ETANÓLICARESUMO: A cigarrinha-das-raízes (Mahanarva fimbriolata) tornou-se praga-chave na cultura da canade-açúcar com a expansão das áreas de colheita sem queima, comprometendo a produtividade e a qualidade da matéria-prima e consequentemente o processamento industrial. Essa pesquisa objetivou avaliar os efeitos da cigarrinha-das-raízes (Mahanarva fimbriolata) sobre a qualidade da cana-de-açúcar e a fermentação do caldo. O delineamento experimental utilizado foi inteiramente casualizado, em esquema fatorial 5 × 2, sendo cinco níveis iniciais de infestação da cigarrinha-das-raízes (0-0,5; 0,6-2,5; 2,6-5; 5,1-8; 8,1-12,5 ninfas m . As analises microbiológicas foram realizadas no início, meio e final do processo. O teor alcoólico e os açúcares redutores residuais totais foram analisados nos vinhos. O ataque da cigarrinhadas-raízes influenciou negativamente a qualidade da cana-de-açúcar, viabilidade celular e de brotos de leveduras e o teor alcoólico dos vinhos. A aplicação do inseticida controlou a praga e resultou em melhor qualidade da cana, viabilidade de células e brotos de leveduras, aumentando a produção de etanol. Palavras-chave: Saccharum spp., Mahanarva fimbriolata, processo fermentativo, produção de etanol

The quality of the raw material defines the industrial potential production. The harvest of raw sugarcane promoted a favorable environment for the increase of Mahanarva fimbriolata (Stål, 1854) pest that affects the plant development. This research was undertaken to evaluate the effects of M. fimbriolata on sugarcane quality and fermentation process. For the technological analysis, four damage levels and two evaluation periods were evaluated, while four fermentation cycles and two evaluation periods were tested for microbiological analysis, with three replications. The determined parameters were Brix (soluble solids), Pol (apparent sucrose), Purity, reducing sugars (RS), total reducing sugars (TRS), Total Acidity, pH and Total Phenolic Compounds in juice. In the fermentation process cellular viability analysis, yeast sprout and bacterial concentration were carried out. The wine was submitted to alcohol content, TRRS (total residual reducing sugars) and fermentation efficiency. The treatment with 60% of damage steams exhibited the lowest averages of Brix, Pol, Purity and TRS of the juice. An increase of the RS% of the juice and content of total phenolic compounds was observed. The cellular and sprouts viability were reduced with the increase in the damages caused by M. fimbriolata. The fermentation process exhibited larger quantities of contaminators. With the damages, the wine TRRS quantity was superior and, consequently there was a decrease of the alcoholic content and fermentation efficiency. The damages caused by M. fimbriolata affected the quality of the raw material, compromising the fermentative process, and increase the production of phenolic compounds and contaminators. Key words: Mahanarva fimbriolata infestation, Saccharum spp., ethanolic fermentation Danos promovidos por cigarrinha-das-raízes na qualidade da cana e processo fermentativo RESUMO: A qualidade da matéria-prima define o potencial de produção da indústria. A colheita de cana sem queima proporcionou um ambiente favorável ao aumento da infestação da Mahanarva fimbriolata (Stål, 1854), que suga a planta e afeta seu desenvolvimento. Avaliaram-se os danos promovidos pela M. fimbriolata na qualidade da cana e no processo fermentativo. Os tratamentos utilizados foram quatro níveis de danos e duas épocas de avaliações para as análises tecnológicas, e quatro níveis de danos, quatro ciclos fermentativos e duas épocas de avaliações para as análises microbiológicas com três repetições. Foram determinados Brix (sólidos solúveis), Pol (sacarose aparente), Pureza, açúcar redutor total (ART), açúcar redutor (AR), Acidez Total, pH, e teor de compostos fenólicos totais no caldo.