31 resultados para Insect sounds.


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The insects of the order Hymenoptera ( bees, wasps, and ants) are classified in two groups, based on their life history: social and solitary. The venoms of the social Hymenoptera evolved to be used as defensive tools to protect the colonies of these insects from the attacks of predators. Generally they do not cause lethal effects but cause mainly inflammatory and/or immunological reactions in the victims of their stings. However, sometimes it is also possible to observe the occurrence of systemic effects like respiratory and/or kidney failure. Meanwhile, the venoms of solitary Hymenoptera evolved mainly to cause paralysis of the preys in order to permit egg laying on/within the prey's body; thus, some components of these venoms cause permanent/transient paralysis in the preys, while other components seem to act preventing infections of the food and future progenies. The peptide components of venoms from Hymenoptera are spread over the molar mass range of 1400 to 7000 da and together comprise up to 70% of the weight of freeze-dried venoms. Most of these toxins are linear polycationic amphipatic peptides with a high content of alpha-helices in their secondary structures. These peptides generally account for cell lysis, hemolysis, antibiosis, and sometimes promote the delivery of cellular activators/mediators through interaction with the G-protein receptor, and perhaps some of them are even immunogenic components. In addition to these peptides, the Hymenopteran venoms also may contain a few neurotoxins that target Na+ and/or Ca+2 channels or even the nicotinic ACh receptor. This review summarizes current knowledge of the biologically active Hymenoptera venoms.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper deals with the phonological definition of trills in Brazilian Portuguese. The phonemic existence of two distinctive R's, one soft the other strong, is taken for granted. After reviewing the ideas of some Portuguese-speaking phoneticians on this matter, 146 occurrences of R's - recorded by two informants - were acoustically analyzed, the formants' general aspect and the length of the R segments were studied in the resulting spectrograms. The phonological table displayed in the conclusion does not include any trill. The soft phoneme /r/, instead, is classified as an interrupted apico-alveolar tap with a retroflex allophone. Naturalization between these two units is discarded.t

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The ability of the stink bug (Nezara viridula) to induce and/or increase production of chemical defenses, i.e., flavonoids, in immature seeds of five genotypes of soybean (BR-16, IAC-100, PI 227687, PI 229358, and PI 274454) was investigated under greenhouse and laboratory conditions. Samples from pods of each genotype damaged by stink bug were analyzed for flavonoid content with high performance liquid chromatography. A dual-choice test was conducted to evaluate the feeding preference of N. viridula comparing BR-16 pods treated with extracts of PI 227687 seeds (with and without stink-bug injury), with water-treated pods. Seeds of PI 227687 damaged by N. viridula presented the highest concentration (352 mug/g) of daidzin (4'-hydroxyisoflavone-7-glucoside). The same trend was observed with genistin (4',5,7-trihydroxyisoflavone-7-glucoside): PI 227687 contained 142.4 mug/g, PI 274454, 31.6 mug/g, and PI 229358, 38.9 mug/g. Seeds damaged by stink bugs had higher isoflavone contents (daidzin and genistin), compared to controls. However, after being damaged, PI 274454 and PI 229358 produced less genistin than the other genotypes and no differences in concentration between damaged and nondamaged plants of this genotypes were observed. The numbers of observations of the insect feeding and the numbers of stylet sheaths left in water-treated BR-16 pods were greater than in those treated with PI 227687 extracts. The insects fed for longer periods on BR-16 pods treated with extract of PI 227687 without injury compared to those that were treated with extract of PI 227687 previously injured by stink bugs. Extracts of PI 227687 pods ( damaged or not) were deterrent to adults of N. viridula, and insect injury increased concentrations of daidzin and genistin in PI 227687 seeds. The deterrence seemed to be more pronounced after pods had suffered stink-bug injury.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) is a common natural predator of defoliating caterpillars in agricultural and forest systems. Insecticides acting as growth regulators of insect pests can indirectly affect their predators through consumption of contaminated prey. We examined the reproductive performance of P. nigrispinus fed on caterpillars of Anticarsia gemmatalis Hubner (Lepidoptera: Noctuidae) reared on soybean leaves exposed to the chitin synthesis inhibitor, diflubenzuron. Caterpillars of A. gemmatalis were fed for 12 h with treated soybean leaves and offered to adults of the predator P. nigrispinus over five consecutive days. The fertility of P. nigrispinus was reduced when feeding on diflubenzuron treated caterpillars, especially at the beginning of the reproductive period, but recovered 3 weeks later. The effects of diflubenzuron ingestion on the life table parameters of P. nigrispinus included an increase in the period taken to double the population size, and reductions in the intrinsic rate of population increase, generation duration, and net reproductive rate. Diflubenzuron therefore had an indirect negative effect on the reproduction and the population dynamics of the non-target predator P. nigrispinus. Clearly, its use in integrated pest management requires further evaluation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An exploratory survey was conducted in Brazil and Paraguay to record insects feeding on Solanum viarum Dunal (Solanaceae). A list of insects collected is included. The survey indicated that a diverse group of phytophagous insects is associated with S. viarum, and some of them may have potential as biocontrol agents of S. viarum in Florida.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Diagnostic insect damage to cocoa tree leaves and fruits were compared in situations with and without the presence of the little fire ants, Wasmannia auropunctata and the closely related and sympatric W. cf rochai. No significant differences in thrips, lepidopteran, or chrysomelid beetle damage to fruits, or to young and old leaves, were associated with these ants. However, significant increases of pseudococcids Planococcus citrii, associated with areas dominated by W. auropunctata, and to a lesser degree with W. cf rochai, were present. W. auropunctata has been reported to be a canopy mosaic dominant in cocoa farms, but the lack of reduced herbivore incidences and its lack of spatial permanence do not support favoring its populations for the management of phytophagous insect control.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We show for the first time that the ventral diverticulum of the mosquito gut (impermeable sugar storage organ) harbors microorganisms. The gut diverticulum from newly emerged and non-fed Aedes aegypti was dissected under aseptic conditions, homogenized and plated on BHI medium. Microbial isolates were identified by sequencing of 16S rDNA for bacteria and 28S rDNA for yeast. A direct DNA extraction from Ae. aegypti gut diverticulum was also performed. The bacterial isolates were: Bacillus sp., Bacillus subtilis and Serratia sp. The latter was the predominant bacteria found in our isolations. The yeast species identified was Pichia caribbica.