Showing papers by "Universidade Federal de Viçosa published in 1998"
TL;DR: This paper explored the uses of metaphor to express various perspectives about the concept of teacher and showed how language teaching methods relate to these metaphors, identifying and fully understanding these contrasting views can heighten perspective-consciousness, increase tolerance and understanding, and make the language classroom a more welcoming environment for students and teachers alike.
250 citations
TL;DR: Eucalyptus spp. are propagated extensively as non-natives in plantations in many parts of the tropics and sub-tropics and a number of diseases result in serious losses to this economically important forest resource as discussed by the authors.
Abstract: Eucalyptus spp. are propagated extensively as non-natives in plantations in many parts of the tropics and sub-tropics. A number of diseases result in serious losses to this economically important forest resource. Eucalyptus rust, caused by Puccinia psidii, is one such example. The economic losses due to this disease are the result of infections of seedlings, young trees, and coppice. P. psidii occurs predominately in Central and South America, but reports of a similar rust are known from other areas. Eucalyptus rust is a remarkable disease in that the pathogen is not known on eucalypts in their centers of origin. It has apparently originated on native Myrtaceae in South America and is highly infective on some Eucalyptus spp. planted there. P. psidii causes one of the most serious forestry diseases in Brazil and is considered to be the most serious threat to eucalypt plantations worldwide. Advances in eucalyptus rust research are reviewed here, with a focus on topics such as distribution, host range, pathogen specialization, symptomatology, etiology, epidemiology, and control.
241 citations
TL;DR: A review of indirect food web interactions in biological control systems is presented and a discussion of the potential impact of functional indirect and direct interactions on food webs and their significance for biological control is discussed.
Abstract: With the increased use of biological control agents, artificial food webs are created in agricultural crops and the interactions between plants, herbivores and natural enemies change from simple tritrophic interactions to more complex food web interactions. Therefore, herbivore densities will not only be determined by direct predator–prey interactions and direct and indirect defence of plants against herbivores, but also by other direct and indirect interactions such as apparent competition, intraguild predation, resource competition, etc. Although these interactions have received considerable attention in theory and experiments, little is known about their impact on biological control. In this paper, we first present a review of indirect food web interactions in biological control systems. We propose to distinguish between numerical indirect interactions, which are interactions where one species affects densities of another species through an effect on the numbers of an intermediate species and functional indirect interactions, defined as changes in the way that two species interact through the presence of a third species. It is argued that functional indirect interactions are important in food webs and deserve more attention. Subsequently, we discuss experimental results on interactions in an artificial food web consisting of pests and natural enemies on greenhouse cucumber. The two pest species are the two-spotted spider mite Tetranychus urticae and the western flower thrips, Frankliniella occidentalis. Their natural enemies are the predatory mite Phytoseiulus persimilis, which is commonly used for spider mite control and the predatory mites Neoseiulus cucumeris and Iphiseius degenerans and the predatory bug Orius laevigatus, all natural enemies of thrips. First, we analyse the possible interactions between these seven species and we continue by discussing how functional indirect interactions, particularly the behaviour of arthropods, may change the significance and impact of direct interactions and numerical indirect interactions. It was found that a simple food web of only four species already gives rise to some quite complicated combinations of interactions. Spider mites and thrips interact indirectly through resource competition, but thrips larvae are intraguild predators of spider mites. Some of the natural enemies used for control of the two herbivore species are also intraguild predators. Moreover, spider mites produce a web that is subsequently used by thrips to hide from their predators. We discuss these and other results obtained so far and we conclude with a discussion of the potential impact of functional indirect and direct interactions on food webs and their significance for biological control.
166 citations
TL;DR: Results show that some of the biomass changes from species, age and spacing differences are related to distribution, not total biomass production, and there were significant differences in total biomass accumulation also.
132 citations
TL;DR: In this paper, the feasibility of immobilizing naringinase in a food contact approved packaging film was evaluated and it was shown that the naredinase had an optimum pH of 3.5 and a pH of 4.0 at 7°C.
Abstract: Naringin, a bitter compound in citrus, may be converted to a nonbitter form by enzymic hydrolysis. Our objective was to determine the feasibility of immobilizing naringinase in a food contact approved packaging film. Naringinase from Penicillium sp. was immobilized in cellulose acetate films with up to 23% efficiency at 7°C. Kinetic studies showed that the free enzyme had an optimum pH=3.5 and the immobilized enzyme pH=4.0. Activation energy decreased upon immobilization (from 14.2 to 11.0 Kcal/mol) thus providing an increased catalytic efficiency for immobilized naringinase. The Michaelis constant for immobilized naringinase (K m =2.1 mM) was lower than for free enzyme (K m =3.6 mM). Keeping films under dry storage for 1 moat room temperature did not cause decreased enzyme activity. A film area/volume ratio (cm 2 /mL of 10° Brix grapefruit juice) of 7.2 hydrolyzed 60% of the naringin in 15 days at 7°C.
125 citations
TL;DR: The main purpose of the GENES software is to help people working with genetic analysis and data processing in breeding programs, using several biometrics models.
Abstract: The main purpose of the GENES software is to help people working with genetic analysis and data processing in breeding programs, using several biometrics models. This software has several help windows that are very friendly to the user. More information about this program is available in the book" Programa GENES - Aplicativo Computacional em Genetica e Estatistica, 442. 1997". Purchase orders are welcome at the following address: editora@mail.ufv.br. Shareware copies of the GENES software are available at http://www.genetica.dbg.ufv.br.
118 citations
TL;DR: The new equations gave numerically lower energy allowable ADG by steers compared to the linear equation currently used by the CNCPS model, which resulted in a lower estimated forage energy value.
Abstract: We used chemical composition and in vitro digestibility data from temperate and tropical forages to develop relationships between indices of lignification and forage indigestible NDF. Neutral detergent fiber indigestibility increased nonlinearly as the lignin concentration of the NDF increased. Differences in estimated indigestible NDF using equations developed for a specific forage class (C3 and C4 grasses and legumes) were small and are probably not biologically significant when compared to those estimated from a common equation. Selected equations were compared with the Cornell Net Carbohydrate and Protein System (CNCPS) for the prediction of ADG. The linear equation (2.4 times NDF lignin content) used by the CNCPS and the Beef NRC had some of the largest errors due to mean bias. A log-log model [4.37 x (lignin/NDF)(.84)] provided the best combination of low total prediction error, low mean bias, and minimal error due to regression bias when permanganate lignin was used. A similar equation based on sulfuric acid lignin [6.17 x (lignin/NDF)(.77)] also met the above criteria. These equations then were evaluated with the CNCPS model against animal growth data from diets ranging in forage quality. Regardless of the equation used for predicting unavailable fiber, the CNCPS underpredicted daily gain, with mean biases ranging from -.10 to -.22 kg/d. Regression bias ranged from .13 to .14 kg/d and the coefficients differed from unity (P = .0001). The new equations gave numerically lower energy allowable ADG by steers compared to the linear equation currently used by the CNCPS model. The estimates were lower due to a higher predicted indigestible NDF, which resulted in a lower estimated forage energy value.
115 citations
TL;DR: In this article, the authors studied the influence of different methods of food preparation routinely used by catering and food services (in large quantities) on the stability of α -carotene, β-carotenes, and total carotenoids in carrots.
113 citations
TL;DR: Crop life analysis was used to investigate the effect of two management methods: within-row plant spacing and insecticidal sprays on yield losses and pest damage on staked tomato plants, and the correlation coefficients indicate that the cumulative losses were more influenced by the fluctuation of fruit losses.
91 citations
TL;DR: In this paper, the effect of temperature and concentration of soluble solids on density of depectined and clarified peach juice and orange juice and a study of the temperature on density for apple and quince purees are reported.
83 citations
TL;DR: Investigation of the effect of cerrado (Brazilian savannah) native vegetation on Lepidoptera associated with Eucalyptus cloeziana plantations suggests that the establishment of strips of native vegetation within Eucaliptus plantation may be a beneficial tactic in the management of defoliator Lepidptera pests in Eucallyptus forests.
TL;DR: Plantations of Eucalyptus intercalated with native vegetation could reduce outbreaks of lepidopteran pests by increasing numbers of Hymenoptera natural enemies of these pests.
TL;DR: Considering that daytime foraging may be necessary for nutritional or metabolical needs, phorids may have a significant impact on their hosts by altering their foraging behavior regardless of the numerical values of parasitism.
Abstract: Females of the parasitic phorid Neodohrniphora sp. were collected in the field and released singly inside an observation chamber placed between a laboratory colony of Atta sexdens (L.) and its foraging arena. The number and speed of loaded and unloaded ants returning to the nest, the weight of foragers and their loads, the number of leaf fragments abandoned by ants, and the number of small workers 'hitchhiking' on leaf fragments were measured before phorids were released, while they were in the observation chamber, and after they were removed. Relatively few ants were attacked by Neodohrniphora sp., but the presence of flies prompted outbound ants to return to the nest and caused a significant reduction on the number and mass of foragers. Additionally, the weight of leaf fragments transported by ants was reduced and the number of abandoned fragments increased in response to Neodohrniphora sp. Presence of the parasitoid caused no significant changes in the number of hitchhiking ants. The regular ants' traffic was resumed after phorids were removed, but foraging activity remained below normal for up to three hours. In the field A. sexdens forages mostly at night, but colonies undergo periods of diurnal foraging during which ants are subject to parasitism from several species of phorid flies. Considering that daytime foraging may be necessary for nutritional or metabolical needs, phorids may have a significant impact on their hosts by altering their foraging behavior regardless of the numerical values of parasitism.
TL;DR: The lipids of crude coffee beans of Catuai Vermalho, Coffea arabica L. harvested in Brazil have been examined as a part of a broader program on their role for the quality of Brazilian coffee.
TL;DR: Use of follicle diameter alone to predict impending ovulation seemed ineffective and results suggested that the echotexture indicator would have been more efficient for initiation of breeding than any of the diameter indicators.
TL;DR: In this article, the authors used active packaging films to reduce the bitterness of grapefruit juice by reducing the naringin and limonin components of the citrus juice by hydrolysis and adsorption.
Abstract: Naringin and limonin are the principle bitterness components of citrus juices. Our objective was to determine if the perceived bitterness in grapefruit juice could be reduced during storage through interaction with active packaging film. Storage of 10° Brix grapefruit juice at 7°C in contact with fungal-derived naringinase immobilized on cellulose acetate film reduced bitterness as perceived by a sensory panel. The films reduced naringin and limonin concentration by hydrolysis and adsorption respectively. Reduction in the naringin and limonin content of grapefruit juice by cellulose acetate films containing immobilized enzyme from 600–400 mg/l and 8.0–6.7 mg/l respectively could be detected as a reduction in bitterness by a sensory panel (p < 0.10). As the area of film (cm2)/volume of juice (ml) ratio increased from 1.1 to 3.6, the time to decrease the naringin level decreased. The reduction in naringin was not affected by agitation or holding the samples quiescently. The amount of enzyme desorbed from the film represented only 2% of the amount of enzyme immobilized in the film. The reduction in bitterness comes from direct interaction with the active packaging films. © 1998 John Wiley & Sons, Ltd.
TL;DR: It seems, therefore, that pest species were constrained by the heterogeneity conferred by the coexistence of Eucalyptus plantations and remnants of native vegetation.
TL;DR: In this article, a study of 600 amostras de agua de diferent mananciais do semi-arido nordestino foram analisadas e estudadas a partir do banco de dados do Laboratorio de Analises de Aguas e Fertilidade do Solo, no Departamento de Solos e Geologia da Escola superior de Agricultura de Mossoro.
Abstract: Mais de 600 amostras de agua de diferentes mananciais do semi-arido nordestino foram analisadas e estudadas a partir do banco de dados do Laboratorio de Analises de Aguas e Fertilidade do Solo, no Departamento de Solos e Geologia da Escola superior de Agricultura de Mossoro. As analises fisico-quimicas permitiram avaliar a qualidade da agua para irrigacao, empregando-se indices classicos da literatura, como Indice de Saturacao de Langelier, CE, RAS, RASaj e RAScor. Na maioria das amostras estudadas observou-se que mais de 30% apresentam problemas devido ao risco de sodicidade (RAS elevada). A maior incidencia de agua com problemas de salinidade (elevada CE) e sodio ocorreu naquela proveniente de pocos tubulares, que captam agua de calcario ou aquiferos abastecidos diretamente pelo lencol freatico. Dependendo do modo como se calculou a RAS, algumas amostras de agua mudaram de classe, quando se empregou o abaco desenvolvido pelo Laboratorio de Salinidade dos Estados Unidos (USSL).
TL;DR: Data suggest that impedance measurement is the method of choice when evaluating the number of bacterial cells adhered to a surface and that the sanitizer PAS and PA were more effective against E. faecium than the other sanitizers.
TL;DR: In this article, the authors analyzed patterns of similarity of RAPD-PCR genomic markers of samples from Parana, Iguacu and Tibagi Rivers to reveal the source of the invading population of Hoplias malabaricus.
Abstract: Hoplias malabaricus, the common trahira, extended its range into the Iguacu River sometime in the last decades. To determine levels of genetic differentiation in neighboring basins of this nominal taxon, as well as to unveil the source of the invading population, we analyzed patterns of similarity of RAPD-PCR genomic markers of samples from Parana, Iguacu and Tibagi Rivers. The high genetic diversity of samples from the Parana and Tibagi Rivers suggested strong population structuring or even the occurrence of undescribed species. All alleles of the sample from the headwaters of Tibagi River were present in the sample from the Iguacu River, which suggests that the former population or another population with similar genetic makeup, may be the source of the trahiras of the Iguacu River.
TL;DR: In this article, the influence of dehydration and different preparation methods during home processing related to carotene, b-carotene and total carotenoids stability in carrots was analyzed.
Abstract: This study aims to analyze the influence of dehydration and different preparation methods during home processing related toa-carotene, b-carotene and total carotenoids stability in carrots. Vitamin A values were evaluated after different treatments. Thus, carrots were submitted to steam cooking, water cooking with and without pressure, moist/dry cooking and conventional dehydration. Determination of a- and b-carotenes was made by High-Performance Liquid Chromatography (HPLC) (conditions were developed by us) using spectrophotometric detection visible-UV at 470 nm; a RP-18 column and methanol: acetonitrile: ethyl acetate (80: 10: 10) as mobile phase. Total carotenoids quantification was made by 449 nm spectrophotometer. The retention of the analyzed carotenoids ranged from 60.13 to 85.64%. Water cooking without pressure promoted higher retention levels of a- and b-carotene and vitamin A values, while water cooking with pressure promoted higher retention levels of total carotenoids. Dehydration promoted the highest carotenoid losses. The results showed that, among the routinely utilized methods under domestic condition, cooking without pressure, if performed under controlled time and temperature, is the best method as it reduces losses in the amount of a- and b-carotene, the main carotenoids present in the carrots. Despite the significant carotenoid losses, carrots prepared through domestic methods, remain a rich source of provitamin A.
TL;DR: In this article, the effect of organic matter on electrochemical properties and dispersion mechanisms was studied in a gibbsitic red-yellow oxisol with electropositive carater.
Abstract: A gibbsitic Red-Yellow Oxisol with electropositive carater was used to study the effect of organic matter on electrochemical properties and dispersion mechanisms. Two organic sources were used, one characterized by non-humified compounds (cattle manure) and another by humified compounds (peat humic acids). The soil was incubated with 0; 7,5; 15,0; 22,5 and 30,0 g kg-1 of organic manure. Water dispersible clay, electrical conductivity, water and KCl pH, and the zero point of saline effect (ZPSE) and superficial electric potential (Ψo) were measured. Clay dispersion behavior was distinct when the soil was treated with cattle manure and humic acids. Soil dispersion increased with the addition of cattle manure, which may be related to the increase of electrical conductivity due to the amount of salts in the manure. On the other hand, the addition of humic acid induced clay flocculation, which was probably due to the formation of clay-humic complexes. The ZPSE linearly decreased with the addition of organic manure, especially with humic acids. The flocculation was not necessarily associated with the low modal condition of Ψo. Negative charge was observed in the treatments with high levels of humic acids, but no clay dispersion was observed, probably due to the electrochemical properties of the humic acids, as a result of its polyeletrolytic condition and the possibility of changing the macromolecule configuration.
01 Dec 1998
TL;DR: The biology of Euschistus heros (F.) (Heteroptera: Pentatomidae) was studied in laboratory under 24±0.5oC, 70±10% RH and photophase of 14 h, and it was observed the deposition of single egg and egg masses according to the number of matings of each tested female.
Abstract: Estudou-se a biologia de Euschistus heros (F.) (Heteroptera: Pentatomidae) em laboratorio sob 24±0,5oC, 70±10% UR e fotofase de 14 h. O tempo medio de desenvolvimento ate adulto foi de 38,6 d, sendo o 2o estadio ninfal, o de maior indice de mortalidade (10,4%). A longevidade de E. heros variou de acordo com o sexo e atividade sexual. Machos e femeas atingiram a maturidade sexual com 11,4 e 11,2 d, respectivamente. O tempo medio para a colocacao de posturas, apos o primeiro acasalamento, variou de 9,1 d para femeas, que acasalaram uma unica vez, ate 13,9 dias para femeas que acasalaram varias vezes durante o periodo de sobrevivencia. O numero medio de ovos por femea variou de 108,5 ate 130,5, dependendo do numero de acasalamento das femeas estudadas. Juntamente com a deposicao das massas de ovos, foi observada a colocacao de posturas isoladas com percentagens de 71,7 e 77,8 respectivamente, tambem dependendo do numero de acasalamentos.
TL;DR: The karyotypes of eight bee species of the genus Melipona are described and compared in terms of heterochromatin content and location (C-banding technique) to identify species with high and low heterochROMatin content.
Abstract: We describe the karyotypes of eight bee species of the genus Melipona and compare them in terms of heterochromatin content and location (C-banding technique). All species had 2n = 18 (females) and n = 9 (males) chromosomes, but a wide variation in heterochromatin content was detected among karyotypes. On the basis of these differences, the species were divided into two functional groups, one of them comprising species with a karyotype having a low heterochromatin content (M. bicolor bicolor, M. quadrifasciata, M. marginata, and M. asilvai), and the other species with a high heterochromatin content (M. seminigra fuscopilosa, M. capixaba, M. scutellaris, and M. captiosa). In the species with high heterochromatin content, heterochromatin occupied practically the entire extent of all chromosomes, with euchromatin being limited to the extremities, a fact that prevented observation of the centromere. In contrast, in the species with karyotypes having a low heterochromatin content, heterochromatin was visualized only in some chromosomes. In the chromosomes in which it was present, heterochromatin was located in the centromere or on the short arm. M. bicolor bicolor had the smallest heterochromatin content with only three chromosome pairs presenting heterochromatin in females. Increased heterochromatin content may be explained by interstitial and pericentromeric growth.
TL;DR: This extract is potentially useful for the control of garlic white rot and its effect will be evaluated under field conditions.
Abstract: The effects of leaf extracts of Brachiaria humidicola, Crotalaria paulina. Eucalyptus citriodora. and Brassica oleracea var. capitata on mycelial growth and sclerotial germination of Sclerotium cepivorum were evaluated in vitro. Water extracts of leaves had little effect on either growth or germination. However, acetone-water leaf extracts usually had the greatest inhibitory effects. Acetone-water extracts reduced mycelial growth more than sclerotial germination. Leaf extracts of E. citriodora at 1000 and 10000p.p.m. in acetone-water completely inhibited mycelial growth and sclerotial germination of S. cepivorum. Thus, this extract is potentially useful for the control of garlic white rot. and its effect will be evaluated under field conditions.
Zusammenfassung
Untersucht wurden die Einflusse von Blattextrakten von Brachiaria humidicola, Crntalaria paulina, Eucalyptus citridora und Brassica oleracea var. capitata auf das Myzelwachstum und die Sklerotienbildung von Sclerotium cepivorum in vitro. Wasserextrakte der Blatter hatten kaum Einflus, weder auf das Wachstum noch auf die Keimung. Am haufigsten hatten jedoch Aceton-Wasser Blattextrakte die grosten hemmenden Effekte. Die Aceton- Wasser-Extrakte reduzierten das Myzelwachstum starker als die Sklerotienkeimung. Die Blattextrakte von E. citriodora verursachten eine vollige Hemmung des Myzelwachstums und der Sklerotienkeimung von S. cepivorum bei einer Konzentration von 1000 bzw. 10000 ppm in Aceton-Wasser. Von daher hat dieses Extrakt das Potential als Bekampfungsmasnahme gegen die Mehlkrankheit in Knoblauch, und dessen Effekt wird unter Freilandbedingungen beurteilt.
TL;DR: The molecular data suggest that the Pisolithus tinctorius isolates analyzed belong to two distinct groups, and suggest new guidelines for future investigations on the taxonomy and systematic of this important fungus species.
Abstract: Twenty Pisolithus tinctorius isolates from different geographic locations and different hosts were characterized by the random amplified polymorphic DNA technique. Thirteen arbitrary primers generated 87 DNA fragments, all of them polymorphic. These data were used to calculate genetic distances among the isolates. The pairwise genetic distances ranged from 1 to 100%, with an average of 58.7%. Cluster analysis based on the amplified fragments grouped the isolates according to their host and geographical origins. Group I contained isolates collected in Brazil and group II those collected in the Northern Hemisphere. In addition to the diversity seen at the molecular level, the isolates also showed host specificity. Greenhouse experiments demonstrated that isolates from the Northern Hemisphere colonized mainly Pinus whereas isolates from Brazil colonized only Eucalyptus. The molecular data suggest that the Pisolithus tinctorius isolates analyzed belong to two distinct groups. The data also suggest new guidelines for future investigations on the taxonomy and systematic of this important fungus species. Furthermore, these results support future experiments aimed at the selection and development of improved isolates of P. tinctorius.
TL;DR: The kinetic model proposed by Figoni and Shoemaker (1983) was used to destroy the thixotropic structure of quince puree by applying a shear rate of 57.6 s -1 for 5 min, and for quince purée for 10 min this article.
Abstract: Orange juice with pulp and pectins is thixotropic at soluble solids concentrations of 55 and 60 °Brix in the range of temperatures from 0 to 20C and shear rate from 7.2 to 57.6 s- 1 . Quince puree is thixotropic at soluble solids concentrations of 12.3 to 28 °Brix in the range of temperatures between 0 to 20C and shear rate from 7.2 to 57.6 S -1 . The thixotropic behaviour of orange juice and quince puree increases with increasing concentration and decreasing temperature and they can be described by the kinetic model proposed by Figoni and Shoemaker (1983). σ=σ e +(σ 0i -σ e )exp(-kt) The thixotropic structure of orange juice was destroyed by applying a shear rate of 57.6 s -1 for 5 min, and for quince puree for 10 min. Quince puree shows a greater thixotropic character than orange juice, because it has a higher content of fiber, pulp and pectins and also because it shows a microscopic structure consisting of long particles and heterogeneous fibers.
TL;DR: It is suggested that application of leading antagonists to living rose leaves and flowers should optimize control of inoculum production by B. cinerea when the tissues die.
Abstract: Microbial isolates from living petals, petal residues and leaf residues of rose, and from laboratory collections, were evaluated for control ofBotrytis cinerea in rose. In leaf residues artificially infested withB. cinerea, isolates of the filamentous fungiGliocladium roseum, FR136 (unidentified) andTrichoderma inhamatum reduced sporulation of the pathogen by >90%, other filamentous fungi were 25–90% effective, and those of yeasts and bacteria were 75%, but isolates ofCladosporium oxysporum and four yeasts were 51–75% effective, and three filamentous fungi, eight yeasts andBacillus subtilis isolates were 26–50% effective. Isolates ofT. inhamatum, C. oxysporum andG. roseum performed best againstB. cinerea among isolates evaluated in leaf residues naturally infested with the pathogen and indigenous microorganisms. Totals of ten isolates of filamentous fungi (includingC. oxysporum andC. cladosporioides), two of yeasts and five ofBacillus subtilis completely prevented lesion production byB. cinerea in detached petals, and a further six isolates of filamentous fungi (includingG. roseum) and six yeasts were 90–99% effective. Isolates ofC. oxysporum, C. cladosporioides andB. subtilis, the most effective microorganisms againstB. cinerea in flower buds, reduced number of lesions in the range of 42–65% compared with 59–89% for a standard fungicide (vinclozolin). It is suggested that application of leading antagonists Jo living rose leaves and flowers should optimize control of inoculum production byB. cinerea when the tissues die. Optimal biocontrol of lesion production in flower buds requires a better understanding of the microenvironment of petals.
TL;DR: The xylitol productivity increased by about 15% with the use of cells of Candida guilliermondii FTI 20037 previously recycled through four consecutive batch cultures and adapted to the sugar cane bagasse hemicellulosic hydrolysate.
Abstract: The xylitol productivity increased by about 15% with the use of cells of Candida guilliermondii FTI 20037 previously recycled through four consecutive batch cultures and adapted to the sugar cane bagasse hemicellulosic hydrolysate. Furthermore, the more concentrated the hydrolysate, the more necessary was the adaptation of the cells, owing to the presence of toxic substances at high concentration which inhibited the xylose-xylitol conversion by the yeast.
TL;DR: Results for threshold temperature and thermal requirement were approximately those reported at constant temperatures by other researchers, while the reproductive parameters of P. nigrispinus were better at intermediate temperatures ranging from 15–25 to 20–30°C.
Abstract: Developmental rates, egg and nymph survival and adult reproduction of Podisus nigrispinus (Dallas) (Het., Pentatomidae) were investigated under six fluctuating temperatures and night–day regimes with a photoperiod of 14 h light: 10 h dark compared with a check temperature of 27 ± 1.5°C. Lower development threshold temperatures for egg, nymphal stage and from egg to adult were estimated at 13.70, 11.96 and 12.68°C with a requirement, respectively, of 54.34, 284.25 and 327.13 degree-days. The highest egg-adult development rate was achieved at 25–35°C. At 10–20°C only 7.0% of nymphs reached adult stage, whereas at 27, 15–25 and 17–27°C, 93.0, 87.3 and 91.1% adult emergence was achieved, respectively. The females that emerged at 10–20°C laid no eggs, while those ar 25–35, 15–25, 17–27 and 27°C produced a total of 92.1, 453.2, 415.0 and 325.0 eggs, respectively. Results for threshold temperature and thermal requirement were approximately those reported at constant temperatures by other researchers, while the reproductive parameters of P. nigrispinus were better at intermediate temperatures ranging from 15–25 to 20–30°C.