Top PDF Performance of insecticides in control of Diatraea saccharalis (Lepidoptera: Crambidae) in sugarcane

Performance of insecticides in control of Diatraea saccharalis (Lepidoptera: Crambidae) in sugarcane

Performance of insecticides in control of Diatraea saccharalis (Lepidoptera: Crambidae) in sugarcane

RESUMO: 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. PALAVRAS-CHAVE: broca da cana-de-açúcar; controle-quí- mico; manejo de pragas.
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Dietas artificiais incorporadas ou não a colmos triturados de variedades de cana-de-açúcar na biologia de Diatraea saccharalis (F.) (Lepidoptera: Crambidae)

Dietas artificiais incorporadas ou não a colmos triturados de variedades de cana-de-açúcar na biologia de Diatraea saccharalis (F.) (Lepidoptera: Crambidae)

with 25% concentration of the components compared to the standard diet had a negative effect in the development of D. saccharlis larvae. Shredded dry stalks incorporated or not to the diet affected only the larval and pupal weight whereas the larval weight was more affected when the resistant (RB83- 5486) and susceptible (SP80-3280) varieties due to the use of diet with 50% of its components. The diet with 100% concentration of its components are more favorable to the development of D. saccharalis, with 25% while that is less favorable. The diet with 100% concentration of the components associated with the presence of SP80-3280 (susceptible) stem variety provides greater larval weight. The weights of larvae and pupae of insects are negatively affected when RB83-5486 (resistant) shredded dry stem variety is incorporated into the diet. regarding to larval weight the diet with 50% of the concentration of its components provides better discrimination between genotypes resistant and susceptible to sugarcane borer.
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Histochemical and Ultrastructural Evidence of Lipid Secretion by the Silk Gland of the Sugarcane Borer Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae)

Histochemical and Ultrastructural Evidence of Lipid Secretion by the Silk Gland of the Sugarcane Borer Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae)

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Susceptibilidade das fases do ciclo de vida de Diatraea saccharalis (Lepidoptera: Crambidae) à ação de fungos entomopatogênicos

Susceptibilidade das fases do ciclo de vida de Diatraea saccharalis (Lepidoptera: Crambidae) à ação de fungos entomopatogênicos

SUMMARY: The mainly target of sugarcane borer control is only for the larvae. However, the efficiency can be higher reaching the lifecycle stages of the pest with more exposure to agents control. The aim of this study was to evaluate the susceptibility of pupae and adults of Diatraea saccharalis to the fungi Metarhizium anisopliae, Beauveria bassiana and Isaria farinosa and to evaluate their effects in pest lifecycle. Newly formed pupae and adults with 24 hours of life were inoculated with conidial fungi suspensions containing 10 6 , 10 7 and 10 8 conidia ml -1 and analyzed several biological parameters of the insect. The treatment with 10 8 con.ml -1 of M. anisopliae and B. bassiana produced significant pupae mortality, also affecting the pupae viability and adults longevity. The fecundity was severely affected by I. farinosa with 10 8 con. ml -1 concentration and by other fungi in all the evaluated concentrations. There was high mortality of treated adults with all concentrations of M. anisopliae and with 10 7 con. ml -1 of B. bassiana. The longevity and fecundity were not affect by fungi, and the eggs viability was significantly reduced by treatment with 10 6 and 10 8 con. ml -1 of B. bassiana.
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Efeitos da queima do canavial sobre parasitóides de larvas e de ovos de Diatraea saccharalis (Fabr.) (Lepidoptera: Crambidae).

Efeitos da queima do canavial sobre parasitóides de larvas e de ovos de Diatraea saccharalis (Fabr.) (Lepidoptera: Crambidae).

ABSTRACT - To evaluate the effects of pre- and post-harvest burning on lar- val and egg parasitoids of Diatraea saccharalis (Fabr.) on sugarcane two har- vesting systems were studied for two consecutive seasons (92/93 and 93/94), i.e., half of the area was burned (CQ), whereas the other half was not burned before mechanical harvesting(CC). In CQ, all trash remaining in the field after harvesting was also burned. After the 92/93 harvesting, and for two years, lar- vae of D. saccharalis were collected from both areas with intervals of three months. They were maintained in the laboratory on artificial diet for 15 days, to estimate the parasitism rates. During the same period, evaluations of parasit- ism on D. saccharalis eggs were made monthly on egg masses, obtained from caged pairs, in the field. These eggs remained on the leaves for a week. The medium larval parasitisms of D. saccharalis, during two years of observations, were 40 and 19.7 % for CC and CQ, while the egg parasitisms were 20.5 and 13.4 % for CC and CQ, respectively. We concluded that pre- and post-harvest- ing burning of sugarcane affects negatively the population of larval parasitoids of D. saccharalis [Metagonistylum minense Townsend, Paratheresia claripalpis Wulp and Cotesia flavipes (Cameron), especially the last one], as well as its egg parasitoids (Trichogramma spp.).
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Within-host competition between two entomopathogenic fungi and a granulovirus in Diatraea saccharalis (Lepidoptera: Crambidae). - Portal Embrapa

Within-host competition between two entomopathogenic fungi and a granulovirus in Diatraea saccharalis (Lepidoptera: Crambidae). - Portal Embrapa

Brazil encompasses the largest grown area that is cultivated with sugarcane and it is the first world leader in the exportation of sugar and ethanol [ 14 ]. The sugarcane borer, Diatraea saccharalis (Fabr., 1794) (Lepidoptera: Crambidae), is the major economically significant pest of sugarcane crops in Brazil, although it has also been recognized as a main pest of corn. Its larval stages are capable of reducing crop yields by feeding on the stalk and thereby facilitating the infection of plant pathogenic fungi through their feeding galleries [ 15 ]. Broad-spectrum chemical insecticides have not shown successful results for controlling this insect, because after hatching, the larvae bore the stem and remain hidden until adult emergence, thus creating a difficult target for most insecticides. The two fungal entomopathogens of the most importance to this pest are Metarhizium anisopliae (Metsch.) Sorok. (Ascomycota: Clavicipitaceae) and Beauveria bassiana (Bals.) Vuill. (Ascomycota: Cordycipitaceae). Both are pathogenic to D. saccharalis in its immature stage, and their asexual spores (conidia) germinate and penetrate directly through the host cuticle. Once inside the host, these fungi grow vegetatively in the hemolymph. After a period of time, the host dies by some combination of the depletion of its resources, direct invasion of tissues by hyphae, or the action of pathogen’s toxins, and then the pathogen sporulates shortly after this [ 16 , 17 ]. Both of the fungal species are currently being applied in order to control different insect pests in sugarcane in Brazil, including spittlebugs (Mahanarva spp. (Stål) [Hemiptera: Cercopidae]) and weevils (Sphenophorus levis Vaurie and Metamasius hemipterus L. [Coleptera: Curculionidae]) [ 18 ]. The larvae of D. saccharalis are also naturally infected by a virus pathogen that, unlike fungi, needs to be ingested. This virus has demonstrated some potential as a biocontrol agent of this pest [ 19 ]. This virus belongs to the
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Distribuição espacial e amostragem sequencial de Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae), na cultura de cana-de-açúcar

Distribuição espacial e amostragem sequencial de Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae), na cultura de cana-de-açúcar

SUMMARY - The aims of this study were: to evaluate the spatial distribution of D. saccharalis larvae in two sugarcane areas, one high and another low infestation intensity, as support for the construction of a sequential sampling plan to be used in integrated pest management of this pest and to evaluate the influence of two lines and the length lines in the method of sample surveys. The surveys were conducted in low infestation intensity area (CTC3 variety) and high infestation intensity area (RB92579 variety) during three development stages of the plant: 4.0, 6.5 and 9.0 months in the cities of Jaboticabal/SP and Quatá/SP, respectively, during the period from March/2009 to July/2008. Were analyzed rates of aggregation for a better description of the pest distribution, as well as the adjustment to a probabilistic model of frequency distribution such as Poisson and Negative Binomial Distributions. The variance/mean relationship index, index of Morisita, the Green coefficient and the k exponent of negative binomial indicated aggregate distribution of D. saccharalis larvae in both areas evaluated, as well as the data were adjusted to the negative binomial distribution rejecting itself, the randomness. Sequential sampling plans have been developed to D. saccharalis larvae and the maximum number of expected samples to making decision was seven sampling units. The comparison between the sample methods indicated that it is necessary to evaluate the two lines of sugarcane, but only 1 meter of length is enough for a representative sample.
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Dispersão de machos de Diatraea saccharalis (Fabricius) (Leipdoptera: Crambidae) em cana-de-açúcar

Dispersão de machos de Diatraea saccharalis (Fabricius) (Leipdoptera: Crambidae) em cana-de-açúcar

Abstract - The sugarcane borer, Diatraea saccharalis (Fabr.), is one of the most important sugarcane pests in Brazil. For a successful utilization of genetically modified crops aiming at the control of this insect, it is necessary to know its dispersal. Studies of flight dynamics can also help understand the insect’s behavior and its ecological interactions. The study of D. saccharalis dispersal was possible through labeling, releasing and capturing adult males. Labeling was performed by incorporating oil soluble dyes into the larval diet. The pheromone traps were placed in a sugarcane field following the cardinal directions (North, South, East, West) around the release site. The results showed that more than 45 % of the labeled males were captured closer to the release site. Climatic factors such as temperature, relative humidity, wind speed and rain do not affect decisively in the release or wild males capture. The wind direction is important in D. saccharalis dispersal, once the majority of insects flew towards the wind. The most adequate model to explain the relationship between flight distance and number of captured insects is = ( + ( , � )) , . Thus, for resistance management of D. saccharalis in genetically modified sugarcane expressing Bacillus thuringiensis Berliner proteins, the refugia sites should be kept at most 800 m apart.
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Efeitos da interação e toxicidade das proteínas Cry1 e Vip3A de Bacillus thuringiensis em Diatraea saccharalis (Fabr., 1794) (Lepidoptera: Crambidae)

Efeitos da interação e toxicidade das proteínas Cry1 e Vip3A de Bacillus thuringiensis em Diatraea saccharalis (Fabr., 1794) (Lepidoptera: Crambidae)

ABSTRACT - Some tropical and sub-tropical plants were genetically engineered with the introduction of cry1 and vip3A genes from Bacillus thuringiensis in order to protect them from several lepidopteran pests. However, it is well known that some of these Cry toxins share receptors in some insect species, which could boost the occurrence of cross-resistance. The knowledge of the effect of Cry1 and Vip3A proteins over one of the most important pests of transgenic crops in the tropics, Diatraea saccharalis (sugarcane borer), has not been completely achieved yet. In the present study, a Brazilian population of D. saccharalis has been tested for the susceptibility to Cry1Aa, Cry1Ab, Cry1Ac, Cry1Fa and Vip3Aa by an artificial diet surface contamination. Cry1 proteins were biotinylated to homologous and heterologous competition assays with midgut brush border membrane vesicles (BBMV) to the target pest. Cry1Ab protein was shown the highest toxicity, followed by Vip3Aa, Cry1Ac, Cry1Fa and Cry1Aa. Cry1Aa protein did not control as well as the other ones. The four Cry1 proteins showed specific binding to the BBMV of the larvae. Based on the results of heterologous competitive binding assays a model of three receptors was suggested; a common receptor for Cry1A’s protein, another receptor for Cry1Fa and Cry1Ab and a different receptor to Vip3Aa. These findings point out that transgenic maize field are currently protected against this insect pest. In addition, the high levels found of Vip3A toxicity and the lack of shared receptors with Cry proteins indicate that these proteins are an interesting alternative candidates for controlling D. saccharalis.
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Resistance of sugarcane cultivars to Diatraea saccharalis

Resistance of sugarcane cultivars to Diatraea saccharalis

The sugarcane borer Diatraea saccharalis Fabr. (Lepidoptera: Crambidae) is one of the most important pests of sugarcane in Brazil and is widely distributed in sugarcane belts across the country (Dinardo-Miranda, 2008). Damage is caused by larvae tunneling into the stalks, causing the death of a large numbers of shoots, when the sugarcane plantation is young, and a sharp reduction in productivity, in more developed sugarcane crops. The infected stalks lose weight, become smaller and thinner, and many wither and die, while others are broken by the wind action. Under favorable conditions, secondary pests, such as Metamasius hemipterus (L.) (Coleoptera: Curculionidae), can also infest sugarcane stalks through the holes made by the borer, increasing losses in the field. The presence of many microorganisms is common, especially of fungi that cause the “red rot” disease, which reduces sucrose content in stalks, due to its conversion into glucose
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PRODUÇÃO DO PARASITÓIDE Cotesia flavipes (HYMENOPTERA: BRACONIDAE) PARA CONTROLE BIOLÓGICO DA BROCA DA CANA-DE-AÇÚCAR (Diatraea saccharalis) (LEPIDOPTERA: CRAMBIDAE)

PRODUÇÃO DO PARASITÓIDE Cotesia flavipes (HYMENOPTERA: BRACONIDAE) PARA CONTROLE BIOLÓGICO DA BROCA DA CANA-DE-AÇÚCAR (Diatraea saccharalis) (LEPIDOPTERA: CRAMBIDAE)

suMMarY: Since the introduction of Cotesia flavipes (larval parasitoid) in Brazil, in 1971, researches has been developed to obtain the best laboratorial methods of massal rearing, aiming the most important plague control in sugarcane, the sugarcane borer Diatraea saccharalis. The actual methods of massal rearing of Cotesia flavipes were verified in this work, as well as the rooms needed in a biological control laboratory, with the propitious environment to rear and maintain host (Diatraea saccharalis) and parasitoid (Cotesia flavipes) during all the year. This work also discuss the necessity of a quality control in the beneficial insects massal rearing, as the pathogen contamination is one of the highest obstacle to get a quality product with desirable performance in field.
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BIOPROSPECÇÃO DE ISOLADOS DE LEVEDURAS E BACTÉRIAS, PROVENIENTES DA SECREÇÃO ORAL DE Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) COLETADA EM CAMPO, ANTAGÔNICOS A

BIOPROSPECÇÃO DE ISOLADOS DE LEVEDURAS E BACTÉRIAS, PROVENIENTES DA SECREÇÃO ORAL DE Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) COLETADA EM CAMPO, ANTAGÔNICOS A

Insect symbionts may have unknown functions in the interaction between insect-plant and insect with microorganisms that co-inhabit the same space. The objective of this study was to investigate the antagonism potential of symbiont microbiota from oral secretion D. saccharalis collected in the field, against Fusarium verticillioides and Colletotrichum falcatum pathogens commonly found inside the cane. For this, 4° and 5° instar caterpillars were collected inside sugarcane varieties RB-835 054 and SP- 813 250, and brought to the lab inside the cane stalks. The microbiota of oral secretion was transferred to two selective media, NA (nutrient agar) for bacteria and DRBC (dicloran Rose Bengal Chloramphenicol) for yeast. Based on morphology and coloration of the colonies twenty colonies of bacteria and yeast were selected. Four culture media were tested in co-cultivation of F. verticillioides and C. falcatum versus bacteria or yeast isolates: PDA (potato, dextrose, agar), YEPD (yeast extract, peptone, dextrose), CCS (supplemented cane broth) and NA (Nutrient Agar). The most suitable culture medium for growth of most microorganisms was BDA. Antagonism potential of 82 bacterial isolates and 87 yeast isolates to C. falcatum and F. verticillioides was assessed using a visual scale of categories 1 to 4, with 4 being the maximum degree of antagonism. Isolates that allocated category greater than or equal to 2 were evaluated in co-culture with C. falcatum and F. verticillioides as the percentage of growth inhibition. It was possible to identify four isolates of bacteria which have the potential to inhibit growth of pathogens and 9 isolates with the same potential but with much lower percentages. These results demonstrate that some isolates of bacteria and yeast may influence the relationship between the bit-rot complex and sugarcane plant, may in future be used as a biological control of these pathogens or have some molecules of biotechnological interest extracted and purified.
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Induction of a gloverin-like antimicrobial polypeptide in the sugarcane borer Diatraea saccharalis challenged by septic injury

Induction of a gloverin-like antimicrobial polypeptide in the sugarcane borer Diatraea saccharalis challenged by septic injury

Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) is an important pest for Brazilian sugarcane. In the present study, we detected two distinct spots in hemolymph from septic injured larvae (HDs1 and HDs2), which are separated by 2DE gel electrophoresis. Both spots were subjected to in-gel tryptic digestion and MALDI-TOF/TOF analysis, which revealed the sequence VFGTLGSDDSGLFGK present in both HDs1 and HDs2. This sequence had homology and 80% identity with specific Lepidoptera antimicrobial peptides called gloverins. Analyses using the ImageMaster 2D software showed pI 8.94 of the HDs1 spot, which is similar to that described to Hyalophora gloveri gloverin (pI 8.5). Moreover, the 14-kDa molecular mass of the spot HDs1 is compatible to that of gloverins isolated from the hemolymph of Trichoplusia ni, Helicoverpa armigera and H. gloveri. Antimicrobial assays with partially purified fractions containing the HDs1 and HDs2 polypeptides demonstrated activity against Escherichia coli. This is the first report of antimicrobial polypeptides in D. saccharalis, and the identification of these peptides may help in the generation of new strategies to control this pest.
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Efeito da endogamia em Cotesia flavipes (Cameron, 1891) (Hymenoptera: Braconidae) criada em Diatraea saccharalis (Fabricius, 1794) (Lepidoptera Crambidae) ao longo de gerações

Efeito da endogamia em Cotesia flavipes (Cameron, 1891) (Hymenoptera: Braconidae) criada em Diatraea saccharalis (Fabricius, 1794) (Lepidoptera Crambidae) ao longo de gerações

ABSTRACT - Although over the years the parasitoid Cotesia flavipes has proved to be effective in controlling populations of the sugarcane borer, Diatraea saccharalis, currently there is concern about the quality control of individuals produced in large scale. One of the main problems of the massal rearing insects refers to inbreeding, resulting in the loss of genetic variability influencing the size, viability and fertility of the offspring, juvenile and adult mortality as well as the morphology of individuals, factors that can compromise the effectiveness of the natural enemy. In this context, we evaluated the biological parameters and flight ability of C. flavipes seeking evidence of the inbreeding effect on the parasitoid quality. Two groups, one from a bio-factory and another inbred laboratory rearing, started from the first, were compared for ten generations. To assure inbreeding, newly emerged females were forced to mate with a brother, being individualized couples and females were used for the parasitism of larvae of D. saccharalis. The evaluations were performed in each of the generations of the parasitoid up to the tenth generation, and recorded the sex ratio, emergence percentage , number of offspring / female, longevity of males and females , the ability of flight and morphometric analysis of adults. At the eleventh generation was studied the parasitism capacity, besides the construction of life tables. The results of the biological characteristics, the ability of flight, morphometric analysis and parasitism capacity showed random significant differences between groups, at times best results were obtained for the biofabric group and sometimes for the inbred group. Also no significant differences across generations for the same group were observed. Thus, the rearing of C. flavipes subjected to inbreeding for ten generations was not sufficient to show deleterious effects of this event on individuals.
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Controle da broca da cana-de-açúcar Diatraea saccharalis (Fabricius, 1794) (Lepidoptera:...

Controle da broca da cana-de-açúcar Diatraea saccharalis (Fabricius, 1794) (Lepidoptera:...

This work aims to study baits added to insecticides used as toxic baits in the control of moths of Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) determining their appropriate doses and distances of application. In laboratory, were tested different baits in terms of selectivity, age and concentration, choice of pesticide and ideal dosage, determining distances within the application area, residual effects and attractiveness to some natural enemies. The D. saccharalis was kept under controlled temperatures (25+1ºC), RH (60+10%) and photophase (14 hours). We evaluated its mortality 24 and 48 hours after exposure to the baits. The selection and concentration of the bait and the pesticide were based on results that presented effiency higher than 80%. Among the different of concentrations of baits and pesticides, we obtained the ideal for each toxic bait as follows: acetic acid (2.5%); acetic acid + 3-methyl-1-butanol (1.25%); gold syrup (20%) and sugar (2.5%) added to cloridrato of cartape (2.0; 2.0; 1.5 and 2.0 g i.a. L -1 solution), respectively. In relation to the distance of application, we observed that the bait does not attract the adult from a distance larger than 50cm, being necessary to spray the baits in the entire area. As for results obtained on the attractiveness to natural enemies (Cotesia flavipes and Doru luteipes), we observed that only the C. flavipes was attracted to molasses baits. In the field, we carried out the spraying of toxic bait in whole area. The treatments were: acetic acid (285mL ha -1 ) + cloridrato de cartape (45 g i.a. ha -1 ), molasses (1,14L ha -1 ) + cloridrato of cartape (45 g i.a. ha -1 ), Bacillus thuringiensis (1L ha -1 ) + Hygrogen (1L ha -1 ) and triflumurom (38,4 g i.a. ha -1 ), being this last one aimed at caterpillars of the 2 nd instar. The treatments based of B. thuringiensis and triflumurom were set up as standard. Results were analyzed regarding the number of caterpillars which appeared after the sprays. Findings showed that the treatment that had better result was based on molasses which was superior than the chemical control with triflumurom, growth regulator pesticide, largely used nowadays mainly in the western of São Paulo state, where there is high level of infestation of sugarcane borer. Thus, the toxic bait based on molasses becomes an alternative to the chemical control of D. saccharalis.
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Diatraea saccharalis (Fabr.) (Lepidoptera: Crambidae) e Mahanarva fimbriolata (Stal) (Hemiptera: Cercopidae) em cana-de-açúcar: impacto na qualidade da matéria-prima, açúcar e etanol

Diatraea saccharalis (Fabr.) (Lepidoptera: Crambidae) e Mahanarva fimbriolata (Stal) (Hemiptera: Cercopidae) em cana-de-açúcar: impacto na qualidade da matéria-prima, açúcar e etanol

Mahanarva fimbriolata (Stål) are key pests of sugarcane. The decision-making for management of each individual pest already elucidated. However, both pests can occur simultaneously. On this situation there is no information on possible decision-making adjustments to control these pests. Therefore, the aim of this study was to evaluate the sugarcane response by the combined attack of borer and spittlebug on yield, raw material quality, sugar, and ethanol production. Two field experiments were carried out in 2010 e 2011 growing seasons, whose plots were 2-m long row of sugarcane plants protected by an anti-aphid screen, and four treatments: plants infested by sugarcane borer, plants infested by spittlebug, plants infested by sugarcane borer + spittlebug, and no infested plants. Stalk and sucrose yield were affected by spittlebug infestation (alone or combined with sugarcane borer). The sugarcane borer increased the fiber content. The combined attack of both pests affected negatively the ashes and color of extracted juice, as well as the turbidity, brix, ashes content, starch and color of clarified juice, the fermentative process (cell viability of yeast) and glycerol of wine. Yield sugar losses per unit injury by each pest are 0.72 and 6.15%, for sugarcane borer and spittlebug, respectively. There is no synergistic effect of combined pests on sugar losses.
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Otimização do controle de Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) por meio do parasitoide Cotesia flavipes (Cameron, 1891) (Hymenoptera: Braconidae) visando a redução de custos

Otimização do controle de Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) por meio do parasitoide Cotesia flavipes (Cameron, 1891) (Hymenoptera: Braconidae) visando a redução de custos

Brazil is the world’s largest producer of sugarcane. However, this agricultural crop is attacked by pests, especially Diatraea saccharalis. Its control in Brazil is carried out mainly by the action of the caterpillar parasitoid, Cotesia flavipes. Therefore, under- standing how the interaction between these two species occurs is vital to increase the effectiveness of this control. This thesis’ goals are to improve the description of the dy- namics among populations and to transform this information into a tool to optimize the biological control of this pest, focusing at the cost reduction for the farmer. In order to de- scribe the dynamics of these two populations, the Lotka-Volterra model and a multi-agent simulation were employed. Through the first model, the characteristics of the differen- tial equations system were obtained, and treatment suggestions to be field tested were presented, in case the pest population size is known. The multi-agent simulation, which by its construction presents more realistic characteristics compared to the Lotka-Volterra model, played a crucial role in the description of the pest in its life cycle phases, where behaviors not observed in the first model were obtained. Afterwards, biological control optimization was developed, taking into account the financial damage that the pest causes in a given period and the cost of its treatment. In order for this procedure to become a useful tool in the farms, an improved survey method has also been proposed. Finally, the results developed here present new solutions so that the biological control of this main sugarcane pest can be carried out more effectively, contributing to the reduction of the employment of chemical products and increasing the competitiveness of this Brazilian industry.
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Atividade inseticida dos óleos de pinhão-manso (Jatropha Curcas L.) e neem (Azadirachta Indica A. Juss.) em ovos de Diatraea Saccharalis (Fabr., 1794) (Lepidoptera: Crambidae).

Atividade inseticida dos óleos de pinhão-manso (Jatropha Curcas L.) e neem (Azadirachta Indica A. Juss.) em ovos de Diatraea Saccharalis (Fabr., 1794) (Lepidoptera: Crambidae).

INSECTICIDE ACTIVITY OF PHYSIC NUT (JATROPHA CURCAS L.) OIL AND NEEM (AZADIRACHTA INDICA A. JUSS.) OIL ON EGGS OF DIATRAEA SACCHARALIS (FABR.) (LEPIDOPTERA: CRAMBIDAE). The aim of this study was to evaluate the effects of physic nut and neem oil on the hatching of caterpillars of Diatraea saccharalis (Fabr., 1794). Tests were conducted in acclimatized chambers at 25 ± 2° C, RH 70 ± 10% and photophase of 12h. The treatments were: distilled water (control), aqueous solution of physic nut oil at 3%; aqueous solution of neem oil at 3%, and aqueous solution of physic nut and neem oil, both at 3%. A total of 250 eggs from D. saccharalis up to 24 hours of age were used for each treatment. Each egg mass containing 50 eggs, constituting one repetition, was immersed three times, for one second, in the respective treatments. Then the eggs were distributed in Petri dishes (5 cm diameter) containing filter paper moistened with distilled water at the bottom to prevent drying of the egg mass. Evaluations were made of the embryonic period and the percentage of hatched larvae of D. saccharalis. Differences were found that indicate that the vegetable oils had a toxic effect on the hatching of sugarcane borer larvae. In the treatment with neem oil only 42.4% of the eggs hatched. In the treatment with physic nut + neem oil 70% of the eggs hatched, and in the treatment with physic nut oil 60% of the eggs hatched. An increase in the embryonic period was also observed, particularly in the treatment with physic nut oil (7.09 days). It can be inferred that the oils of neem and physic nut affected the hatching of D. saccharalis eggs, with an insecticide effect.
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Efeito do número de adultos de Trichogramma galloi Zucchi, 1988 (Hymenoptera: Trichogrammatidae) liberados em semanas sucessivas, para o controle de Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae).

Efeito do número de adultos de Trichogramma galloi Zucchi, 1988 (Hymenoptera: Trichogrammatidae) liberados em semanas sucessivas, para o controle de Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae).

20 m) separated by 20 m from each other. The experimental plots were artificially infested with twenty D. saccharalis couples once a week (two couples for cage, corresponding a ten repetition per treatment). T. galloi adults were released weekly, in the first 24 hour after infestation, in the center of each one of the subareas, as follows: a- Control (no release); b- 4,000 adults (100,000 T. galloi/ hectare); c- 8,000 adults (200,000 T. galloi/hectare); d- 10,000 adults (250,000 T. galloi/hectare). The results evidenced that the amount of parasitoids released in consecutive weeks at areas infested with eggs of D. saccharalis may still maintain high levels of parasitism. The best release rates of T. galloi were between 150,000 and 175,000 parasitoids adults per hectare per week.
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Esterase-3 polymorphism in the sugarcane borer Diatraea saccharalis (Lepidoptera, Pyralidae)

Esterase-3 polymorphism in the sugarcane borer Diatraea saccharalis (Lepidoptera, Pyralidae)

forces such as bottleneck or founder effects. The studyof esterases in laboratorypopulations of D. saccharalis indi- cates that the data obtained byConte (1994) on infestation control byhymenopteran parasites can be applied to natural populations. This is the most important aspect of our study because it shows that the information about genetic diver- sityin D. saccharalis laboratorypopulations can support biological control programs aimed at this species, since af- ter being maintained for at least 4 generations under labora- toryconditions the moths still behaved as if theywere randomlymating in nature.
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