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1.
Exp Parasitol ; 204: 107732, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31374184

RESUMO

In the present study, the cytotoxic effects of amitraz, an octopamine receptor agonist on the reproductive system of engorged adult females of Rhipicephalus (Boophilus) annulatus were assessed using histology, electron microscopy and octopamine beta (OCTß) receptor transcriptional expression analysis. Adult immersion test (AIT) was performed by immersing the fully engorged female ticks for 2 min in different concentrations of amitraz (200, 250, 300, 350 ppm). Amitraz at the dose of 300 ppm, caused an adult tick mortality of 16.66 ±â€¯6.80 per cent, inhibition of fecundity of 75.80 per cent and hatching of 50 per cent of ova laid by treated ticks. Histological changes in the ovaries of ticks collected after 24 h of treatment with amitraz (300 ppm), in comparison with controls (distilled water/methanol) were identified by microscopical examination of sections (4  µm) stained using haematoxylin and eosin. These changes included reduction in size and basophilia of stage I oocytes, presence of cytoplasmic vacuoles of various sizes around germinal vesicle of stage II oocytes, wavy basement membrane of stage III oocytes and reduction in size and number of mature stage IV and V oocytes. Electron microscopy was employed for understanding the structural changes in the ultrathin sections (60 nm) of ovaries. Ticks treated with amitraz showed major ultrastructural changes such as irregular nuclear membrane, crystolysis of mitochondria and detachment of external and internal layers of basal lamina of oocytes. The cDNA synthesized from the total RNA of whole ticks and ovaries of ticks treated with amitraz along with controls were used for relative quantification of Octopamine ß receptor (OCTß-R) expression based on the 2-ΔΔCT method by quantitative real time PCR (qRT PCR). Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as endogenous control. Down regulation of expression of OCTß-R mRNA in the ovaries of amitraz treated ticks was observed compared to controls. Thus, the inhibition of fecundity observed in the ticks treated with amitraz can be attributed to the major structural changes and decreased expression of OCT ß receptor mRNA induced by it in the ovary.


Assuntos
Inseticidas/farmacologia , Rhipicephalus/efeitos dos fármacos , Toluidinas/farmacologia , Análise de Variância , Animais , Membrana Basal/efeitos dos fármacos , Membrana Basal/ultraestrutura , Regulação para Baixo , Feminino , Fertilidade/efeitos dos fármacos , Expressão Gênica , Microscopia Eletrônica de Transmissão , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/ultraestrutura , Oócitos/efeitos dos fármacos , Oócitos/ultraestrutura , Ovário/anatomia & histologia , Ovário/efeitos dos fármacos , Ovário/ultraestrutura , Oviposição/efeitos dos fármacos , RNA Mensageiro/isolamento & purificação , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Amina Biogênica/agonistas , Receptores de Amina Biogênica/efeitos dos fármacos , Rhipicephalus/anatomia & histologia , Rhipicephalus/genética , Rhipicephalus/ultraestrutura , Espectrofotometria , Controle de Ácaros e Carrapatos/métodos , Vacúolos/efeitos dos fármacos , Vacúolos/ultraestrutura
2.
Ecotoxicol Environ Saf ; 182: 109448, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31398781

RESUMO

The electrocoagulation (EC) technique is an alternative method of isolating natural products with the advantage of minimizing the amounts of organic solvents required for this process, which are often harmful to the environment. In this research, the EC and the conventional solvent extraction methods were used in the isolation of Stemona alkaloids from the aerial parts of Stemona aphylla. A comparison was made between the amounts of the isolated alkaloids and the solvents used. The isolated alkaloids were evaluated for their larvicidal, ovicidal and oviposition-deterrent activities against the dengue vector, Aedes aegypti. The morphology and histopatology of the alkaloid treated larvae were also investigated. Two Stemona alkaloids, (2'S)-hydroxystemofoline and stemofoline, were isolated from both the EC and the conventional method. The amounts of (2'S)-hydroxystemofoline from the EC method was about the same as that obtained from the conventional method. However, the amounts of stemofoline obtained from the EC method were about two times larger than those obtained from the conventional method. Importantly, the EC method required six times less total organic solvents. The larvicidal activity assays of (2'S)-hydroxystemofoline and stemofoline showed that these were highly effective against Aedes aegypti larvae with LC50 values of 3.91 µg/ml and 4.35 µg/ml, respectively. Whereas, the crude EC extract (LC50 = 11.86 µg/ml) showed greater larvicidal activity than the crude extract obtained from the conventional extraction method (LC50 = 53.40 µg/ml). The morphological observations of the (2'S)-hydroxystemofoline and the stemofoline treated larvae revealed that the anal gills were the sites of aberrations. A histopathological study showed that larvae treated with these alkaloids had cytopathological alterations to the epithelial cells of the midgut. At a concentration 40 µg/ml (2'S)-hydroxystemofoline showed 100% ovicidal activity on 24 h old eggs while stemofoline showed 97.2%. Furthermore, the oviposition-deterrent effects of (2'S)-hydroxystemofoline and stemofoline, at a concentration of 80 µg/ml were 99.5% and 97.2%, respectively.


Assuntos
Aedes/efeitos dos fármacos , Alcaloides/toxicidade , Controle de Mosquitos/métodos , Componentes Aéreos da Planta/química , Extratos Vegetais/toxicidade , Stemonaceae/química , Animais , Dengue/transmissão , Vetores de Doenças , Eletrocoagulação , Feminino , Compostos Heterocíclicos de 4 ou mais Anéis , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Mosquitos Vetores , Oviposição/efeitos dos fármacos
3.
J Chem Ecol ; 45(8): 693-707, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31367970

RESUMO

Crop domestication and selective breeding have altered plant defense mechanisms, influencing insect-plant interactions. A reduction in plant resistance/tolerance against herbivory is generally expected in domesticated species, however, limited efforts have been made to compare inducibility of plant defenses between wild and domesticated genotypes. In the present study, the inducibility of several plant defense mechanisms (e.g. defensive chemicals, trichomes, plant volatiles) were investigated, and the performance and preference of the herbivore Helicoverpa zea were measured in three different tomato genotypes; a) wild tomato, Solanum pimpinellifolium L. (accession LA 2093), b) cherry tomato, S. lycopersicum L. var. cerasiforme (accession Matts Wild Cherry), and c) cultivated tomato, S. lycopersicum L. var. Better Boy). Enhanced inducibility of defensive chemicals, trichomes, and plant volatiles in the cultivated tomato, and a higher level of constitutive plant resistance against herbivory in the wild genotype was observed. When comparing the responses of damaged vs. undamaged leaves, the percent reduction in larval growth was higher on damaged leaves from cultivated tomato, suggesting a higher induced resistance compared to other two genotypes. While all tomato genotypes exhibited increased volatile organic compound (VOCs) emissions in response to herbivory, the cultivated variety responded with generally higher levels of VOCs. Differences in VOC patterns may have influenced the ovipositional preferences, as H. zea female moths significantly preferred laying eggs on the cultivated versus the wild tomato genotypes. Selection of traits during domestication and selective breeding could alter allocation of resources, where plants selected for higher yield performance would allocate resources to defense only when attacked.


Assuntos
Lycopersicon esculentum/química , Mariposas/fisiologia , Solanum/química , Animais , Comportamento Animal/efeitos dos fármacos , Catecol Oxidase/metabolismo , Feminino , Genótipo , Herbivoria , Larva/fisiologia , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Oviposição/efeitos dos fármacos , Fenóis/análise , Folhas de Planta/química , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia , Proteínas de Plantas/análise , Análise de Componente Principal , Inibidores de Proteases/química , Solanum/genética , Solanum/metabolismo , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/farmacologia
4.
J Chem Ecol ; 45(8): 715-724, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31385154

RESUMO

Plants emit a specific blend of volatiles in response to herbivory and these volatiles, which often attract predators and parasitoids function as an indirect plant defense. The impact of plant volatiles in shaping herbivore defenses is unclear. Here, we report that specific plant volatiles induce immune responses in the polyphagous herbivore, Spodoptera litura. We characterized the hemocyte profile and established their functional significance with respect to ontogeny and exposure to specific plant volatiles. Fifth instar larvae showed the highest number and hemocytes diversity. We characterized seven different types of hemocytes, of which granulocytes performed phagocytosis, oenocytoids showed melanization activity, and plasmatocytes along with granulocytes and oenocytoids were found to be involved in encapsulation. Among the six volatiles tested, exposure to (E)-ß-ocimene caused the highest increase in total hemocytes number (THC) followed by linalool and (Z)-3-hexenyl acetate exposure. Although THC did not differ between these three volatile treatments, circulating hemocytes diversity varied significantly. (E)-ß-ocimene exposure showed higher number of plasmatocytes and phenol oxidase activity. The interaction of the parasitic wasp Bracon brevicornis with (E)-ß-ocimene exposed larvae was poor in terms of delayed paralysis and lower egg deposition. In choice assays, the wasp showed clear preference towards control larvae indicating (E)-ß-ocimene treatment renders the host unattractive. Hemocyte profiles post-parasitoid exposure and (E)-ß-ocimene treatment were similar indicating cue-based priming. When challenged with Bacillus thuringiensis, linalool exposure resulted in the highest survival as compared to other volatiles. Our results show that specific HIPVs can modulate cellular immunity of S. litura, revealing a new role for HIPVs in tri-trophic interactions.


Assuntos
Compostos Orgânicos Voláteis/farmacologia , Vespas/fisiologia , Alcenos/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Hemócitos/citologia , Hemócitos/efeitos dos fármacos , Hemócitos/metabolismo , Herbivoria , Interações Hospedeiro-Parasita , Sistema Imunitário/efeitos dos fármacos , Sistema Imunitário/metabolismo , Larva/fisiologia , Monofenol Mono-Oxigenase/metabolismo , Monoterpenos/farmacologia , Oviposição/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Plantas/química , Plantas/metabolismo , Plantas/parasitologia , Compostos Orgânicos Voláteis/química , Vespas/imunologia
5.
Exp Parasitol ; 204: 107720, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31279929

RESUMO

Parasite life history can be affected by conditions of the host and of the external environment. Rapamycin, a known immunosuppressant of mammals, was fed to laboratory mice that were then infected with the Trichostrongylid nematode Heligmosomoides bakeri to determine if host rapamycin exposure would affect parasite survival, growth, and reproduction. In addition, adult worms from control fed mice were directly exposed to rapamycin to assess if rapamycin would affect worm viability and ex vivo reproduction. We found that host ingestion of rapamycin did not affect H. bakeri survival or growth for male or female worms, but female worms had increased reproduction both in vivo and when removed from the host and cultured ex vivo. After direct rapamycin exposure, motility of female worms was greater at low levels of rapamycin compared to high levels of rapamycin or high levels of DMSO (the vehicle used to solubilize rapamycin) in control media, but was similar to females in low levels of DMSO in control media. Male motility was not affected by the presence of rapamycin or DMSO in the media. Ex vivo egg deposition was higher when exposed to rapamycin than when cultured in control media that contained DMSO, regardless of DMSO dose. Overall, we conclude that host ingestion of rapamycin or direct exposure to rapamycin was generally favorable or neutral for parasite life history traits.


Assuntos
Heligmosomatoidea/efeitos dos fármacos , Imunossupressores/farmacologia , Sirolimo/farmacologia , Análise de Variância , Animais , Dimetil Sulfóxido/administração & dosagem , Dimetil Sulfóxido/farmacologia , Feminino , Heligmosomatoidea/crescimento & desenvolvimento , Heligmosomatoidea/fisiologia , Imunossupressores/uso terapêutico , Intestino Delgado/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Movimento/efeitos dos fármacos , Oviposição/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Fatores Sexuais , Razão de Masculinidade , Sirolimo/uso terapêutico
6.
J Chem Ecol ; 45(7): 626-637, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31257561

RESUMO

Since the first reports of damage by Drosophila suzukii, the spotted-wing Drosophila (SWD), over a decade ago in Europe, widespread efforts have been made to understand both the ecology and the evolution of this insect pest, especially due to its phylogenetic proximity to one of the original model organisms, D. melanogaster. In addition, researchers have sought to find economically viable solutions for the monitoring and management of this agricultural pest, which has now swept across much of Europe, North America and Asia. In a new direction of study, we present an investigation of plant-based chemistry, where we search for natural compounds that are structurally similar to known olfactory cues from parasitoid wasps that in turn are well-described ovipositional avoidance cues for many Drosophila species. Here we test 11 plant species across two plant genera, Nepeta and Actinidia, and while we find iridoid compounds in both, only those odorants from Actinidia are noted to be detected by the insect antenna, and in addition, found to be behaviorally active. Moreover, the Actinidia extracts resulted in oviposition avoidance when they were added to fruit samples in the laboratory. Thus we propose the possible efficacy of these plants or their extracted chemistry as a novel means for establishing a cost-effective integrated pest management strategy towards the control of this pest fly.


Assuntos
Actinidia/química , Produtos Biológicos/química , Drosophila/fisiologia , Controle de Insetos/métodos , Nepeta/química , Actinidia/metabolismo , Actinidia/parasitologia , Animais , Produtos Biológicos/farmacologia , Produtos Agrícolas , Drosophila/efeitos dos fármacos , Drosophila/crescimento & desenvolvimento , Cromatografia Gasosa-Espectrometria de Massas , Nepeta/metabolismo , Nepeta/parasitologia , Oviposição/efeitos dos fármacos , Folhas de Planta/química , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia
7.
Anim Sci J ; 90(7): 880-886, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31111618

RESUMO

An experiment using 96 Hy-Line brown laying hens at 29 weeks of age that were randomly allocated to four treatments with eight replicates was conducted to assess the effects of star anise (Illicium verum Hook.f.) oil (SAO) on nutrient and energy utilization. Dietary treatments were corn-soybean meal-based diets supplemented with 0, 200, 400, and 600 mg/kg SAO. The birds were fed the diets for 14 days. The conventional nutrients and amino acids of feed and excreta samples were measured for calculating apparent metabolic efficiency, and gross energy (GE) was analyzed for computation of apparent metabolic energy (AME) and true metabolic energy (TME). Endogenous losses were obtained from another 16 birds for calculating true metabolic efficiency. Birds supplemented with SAO had higher (p < 0.05) metabolic efficiency of crude protein (CP), organic matter (OM), Lys, Met, Arg, and Thr than those of control group. Quadratic effects on utilization of Lys, Met, and Thr were observed (p < 0.05). Inclusion of SAO to diet improved nutrient utilization, and the efficacy is best at 400 mg/kg.


Assuntos
Ração Animal , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Galinhas/metabolismo , Galinhas/fisiologia , Dieta/veterinária , Suplementos Nutricionais , Metabolismo Energético/efeitos dos fármacos , Illicium/química , Óleos Voláteis/farmacologia , Oviposição/efeitos dos fármacos , Aminoácidos/metabolismo , Animais , Proteínas na Dieta/metabolismo , Feminino , Óleos Voláteis/isolamento & purificação
8.
J Therm Biol ; 81: 20-24, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30975419

RESUMO

This study was done to evaluate the effects of Chinese herbal medicine (CHM) and ginger powder on layers-production performance, serum metabolites and antioxidant status under heat stress condition. Two hundred and fifty Lohmann layers were randomly divided into 5 different, including two controls and three experimental groups (H1, H2, and H3). Control groups were fed the basic diet without supplementation, while, the feed of three experimental groups was supplemented with 3.32 g CHM, 10 g ginger powder, and 10 g ginger powder+ 3.32 g CHM per kg of diet, respectively. Results showed that feed consumption and production rate were decreased in the HC group, while, feed intake and production significantly improved when birds were given supplemented diet. The production rate and feed intake of the H3 group were even significantly higher than the NC group. The birds that received supplemented diet had higher glucose level compared to HC. Triglycerides and serum cholesterol had significantly decreased level in supplemented groups compared to HC. Fungal catalase (CAT) level was significantly improved in H2 and H3 groups. Nitric oxide (NO), glutathione peroxidase (GSH-PX) and Total Protein (T-AOC) level were significantly improved in supplemented groups. Findings showed that ginger powder and CHM could be a viable alternative to the synthetic antibiotic in poultry feed.


Assuntos
Antioxidantes/metabolismo , Galinhas/sangue , Galinhas/metabolismo , Medicamentos de Ervas Chinesas/administração & dosagem , Gengibre , Resposta ao Choque Térmico/efeitos dos fármacos , Oviposição/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição Animal , Animais , Suplementos Nutricionais , Ingestão de Alimentos , Feminino , Temperatura Alta , Medicina Tradicional Chinesa
9.
Poult Sci ; 98(8): 3298-3303, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30993323

RESUMO

Dietary supplementation with the isoflavone, daidzein, has been shown to improve egg production in poultry. Additionally, providing Chinese herbs (CH) in the broiler diet has led to increased antioxidative enzyme activity. However, the combined effect of these dietary supplements on hen performance has not been examined. Therefore, the objective of this study was to determine if dietary supplementation with a mixture of daidzein and CH would alter laying performance, egg quality, and blood plasma constituents of post-peak laying hens. At 59 wk of age, Hyline brown hens (240) were randomly allocated to 2 dietary groups and fed for 16 wk. The control group received the basal diet, and a treatment group was fed the basal diet that contained 0.02% of a mixture of daidzein and CH. Egg production and weight were recorded daily and egg quality data were collected at 75 wk of age. Blood plasma antioxidant activity, hormone levels, mineral (Ca and P) content, and osteocalcin content were determined at the end of the study. The results showed that laying rate, egg mass, and shell strength were greater in the daidzein-CH mixture group than the controls (P < 0.05). The plasma glutathione peroxidase, superoxide dismutase, and luteinizing hormone levels were also greater in the daidzein-CH mixture group compared with the control group (P < 0.05). The results of this study reveal that supplementing diets with a daidzein-CH mixture can improve laying performance perhaps by increasing plasma antioxidant activity, luteinizing hormone levels, and mineral content.


Assuntos
Ração Animal/análise , Galinhas/fisiologia , Medicamentos de Ervas Chinesas/farmacologia , Casca de Ovo , Isoflavonas/farmacologia , Envelhecimento , Animais , Antioxidantes/análise , Cálcio/sangue , Dieta/veterinária , Feminino , Hormônio Luteinizante/sangue , Osteocalcina/sangue , Oviposição/efeitos dos fármacos , Fósforo/sangue
10.
Mem Inst Oswaldo Cruz ; 114: e180489, 2019 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-30970079

RESUMO

BACKGROUND: This work describes a chemical study of the essential oil from leaves of Xylopia ochrantha, an endemic Annonaceae species from Brazil, and its activity against Biomphalaria species. Considering its poor solubility in aqueous medium, the essential oil was nanoemulsified to evaluate its action on controlling some mollusc species of genus Biomphalaria, snail hosts of Schistosoma mansoni that causes schistosomiasis, which mainly affects tropical and subtropical countries. OBJECTIVES: The main aims of this work were to analyse the chemical composition of essential oil from X. ochrantha, and to evaluate the effect of its nanoemulsion on molluscs of genus Biomphalaria and their oviposition. METHODS: Chemical analysis was performed by gas chromatography coupled to mass spectrometry. Nanoemulsions were prepared by a low energy method and characterised by particle size and polydispersity index. Biological assays evaluating the mortality of adult species of B. glabrata, B. straminea and B. tenagophila and their ovipositions upon contact with the most stable nanoemulsion during 24 and 48 h were performed. FINDINGS: Chemical analysis by mass spectrometry revealed the majority presence of bicyclogermacrene and germacrene D in the essential oil. The formulation with a hydrophilic-lipophilic balance (HLB) of 9.26 was the most suitable for the oil delivery system. This nanoemulsion caused the mortality in B. tenagophila, B. straminea and B. glabarata of different sizes at levels ranging from 50 to 100% in 48 h. Additionally, the formulation could inhibit the development of deposited eggs. CONCLUSION: Thus, these results suggest the use of nanoemulsified essential oil from X. ochrantha as a possible alternative in controlling some Biomphalaria species involved in the schistosomiasis cycle.


Assuntos
Biomphalaria/efeitos dos fármacos , Vetores de Doenças , Óleos Voláteis/farmacologia , Oviposição/efeitos dos fármacos , Xylopia/química , Animais , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Óleos Voláteis/isolamento & purificação , Esquistossomose mansoni/transmissão
11.
Ticks Tick Borne Dis ; 10(4): 781-786, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30935855

RESUMO

This work aimed to investigate candidate biological control agents against the cattle tick Rhipicephalus microplus by studying three entomopathogenic nematodes (EPN) isolates from two species, Heterorhabditis bacteriophora (isolates LPP30 and HP88) and Heterorhabditis baujardi (isolate LPP7). The study comprised the pharmacotechnical development of four test formulations, and their biological evaluation, in three stages: 1) selection of the fittest EPN isolate at 16 ± 1 °C after 120 h of incorporation in the formulations; 2) determination of the effects of temperature and incubation time on the survival of the selected isolate in formulations; 3) evaluation of the in vitro efficacy (infectivity) of the selected EPN formulations and their components against R. microplus females after 72 h exposure. H. baujardi LPP7 presented the highest survival rates in 0.1% carboxymethyl cellulose sodium (CMC) formulations (100% at 25 °C, up to 10 days after incorporation). At the highest tested temperature (34.2 °C), 54% of LPP7 survived for up to 72 h in CMC formulations. The infectivity of LPP7-containing formulation against R. microplus was 99%, reducing oviposition, egg production index and larval hatching. Considering the pressing need for safer acaricide products, incorporation of EPNs in pharmaceutical formulations is presented as a promising approach for the biological control of cattle tick infestations, potentially reducing environmental impact and resistance development associated with chemical acaricides.


Assuntos
Agentes de Controle Biológico , Nematoides/fisiologia , Controle Biológico de Vetores/métodos , Rhipicephalus/efeitos dos fármacos , Termotolerância , Animais , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/parasitologia , Composição de Medicamentos , Feminino , Larva/efeitos dos fármacos , Oviposição/efeitos dos fármacos , Infestações por Carrapato/tratamento farmacológico , Infestações por Carrapato/veterinária
12.
J Insect Sci ; 19(2)2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30822780

RESUMO

The discovery of inexpensive, readily available bioflavonoids, and their degradation products that boost the reproductive potential of mass-reared predators is the overarching goal of this research. We tested the hypothesis that 2,4-dihydroxybenzoic acid (DHBA), an inexpensive degradation product of morin (a flavonol bioflavonoid), stimulates oviposition by the ladybird beetle Coleomegilla maculata (DeGeer). We also tested the hypothesis that C. maculata females must touch or taste DHBA to stimulate oviposition. We setup bioassays in communal cages (housing 10 females) and solitary cages (housing 1 female). In communal cages, nearly all egg clutches were found in or near the chemical dish with DHBA only. Provisioning cages with a tissue substrate reduced oviposition in the chemical dish. Regardless of oviposition site, egg number per clutch did not increase in communal cages or solitary cages with DHBA only. Affixing DHBA to the base of the chemical dish, then covering it with a nylon screen, reduced oviposition. This study suggests that females must touch or taste DHBA to stimulate oviposition. The physiological mechanism involved in oviposition stimulation requires further study. DHBA could potentially serve as a weak oviposition stimulant for predatory ladybird beetles in some mass-rearing systems.


Assuntos
Besouros/fisiologia , Hidroxibenzoatos/farmacologia , Oviposição/efeitos dos fármacos , Animais , Besouros/efeitos dos fármacos , Sinais (Psicologia) , Feminino , Distribuição Aleatória , Reprodução/efeitos dos fármacos , Paladar , Tato
13.
Sci Total Environ ; 667: 248-254, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30831364

RESUMO

Animals can modulate their own exposure to environmental contaminants through behavioral plasticity such as diet and habitat choice. However, it remains unclear if behavior also has cascading effects on contaminant exposure across multiple generations. In insects, oviposition site selection is an important behavior females can use to modify offspring contaminant exposure risk. In this study, we use the yellow fever mosquito, Aedes aegypti, to test how methylmercury (MeHg) affects oviposition site selection. We found that mosquito larval development rate and survival were negatively affected at MeHg concentrations ≥100 ppb. Adult females not exposed to MeHg as larvae avoided oviposition sites with high MeHg concentrations (>50 ppb), but MeHg exposure at the larval stage significantly affected this oviposition site selection. Specifically, females raised from larvae exposed to non-toxic MeHg levels (i.e., five-50 ppb) showed a significant increase in preference for oviposition sites contaminated with toxic MeHg concentrations (≥500 ppb), compared to unexposed controls. This maladaptive behavioral response could be because, when conditioned with non-toxic MeHg concentrations, MeHg-associated olfactory cues act as a "supernormal" stimulus during oviposition site selection. Importantly, however, this maladaptive behavioral response is eliminated in female mosquitoes raised from larvae exposed to toxic MeHg concentrations (i.e. 100 ppb), and these mosquitoes showed a significant increase in preference for MeHg uncontaminated oviposition sites, compared to unexposed controls. Thus, in mosquitoes, the magnitude of MeHg exposure in one generation can impact MeHg exposure in subsequent generations by altering oviposition site selection behavior. Our results have broad implications for our understanding of how contaminant-mediated behavioral modifications can feedback on contaminant exposure risk across multiple generations, and consequently how behavior can affect the evolutionary trajectory of organisms inhabiting a heterogeneously contaminated environment.


Assuntos
Aedes/efeitos dos fármacos , Quimiotaxia , Compostos de Metilmercúrio/metabolismo , Percepção Olfatória , Oviposição/efeitos dos fármacos , Adaptação Biológica , Aedes/fisiologia , Animais , Feminino
14.
J Chem Ecol ; 45(4): 371-377, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30880353

RESUMO

The common grass yellow Eurema mandarina (Lepidoptera: Pieridae) uses the silk tree Albizia julibrissin (Fabaceae) as a primary host in Japan. We previously reported that D-pinitol, a cyclitol found in fresh leaves of A. julibrissin, solely elicits moderate oviposition responses from females. However, the aqueous neutral/amphoteric fraction of the fresh leaf extract containing D-pinitol weakly induces oviposition. Moreover, the aqueous neutral/amphoteric/basic fraction was significantly more active than the neutral/amphoteric fraction in eliciting responses, indicating that some basic compounds are involved in stimulating oviposition. High-resolution mass spectrometry and proton nuclear magnetic resonance measurements revealed that the aqueous basic faction contains N,N,N-trimethylglycine (trivial name: glycine betaine) in alkali metal salt form. The average concentration of this quaternary ammonium compound in fresh leaves was estimated to be 0.012% w/w in high performance liquid chromatography analyses. The authentic N,N,N-trimethylglycine induced oviposition at concentrations greater than 0.001% (w/v) and slightly enhanced female responses to the aqueous neutral fraction and authentic D-pinitol. However, its analogues, N,N-dimethylglycine, N-methylglycine, and glycine as well as its precursor choline were inactive. These results demonstrate that N,N,N-trimethylglycine, together with D-pinitol, serves as an stimulant of E. mandarina for oviposition on the leaves of A. julibrissin.


Assuntos
Albizzia/química , Betaína/farmacologia , Lepidópteros/fisiologia , Oviposição/efeitos dos fármacos , Extratos Vegetais/farmacologia , Sarcosina/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia por Troca Iônica , Feminino , Folhas de Planta/química , Espectroscopia de Prótons por Ressonância Magnética , Sarcosina/análogos & derivados , Espectrometria de Massas por Ionização por Electrospray
15.
Parasitol Res ; 118(3): 743-750, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30719534

RESUMO

Surveillance is not only an important tool to assess the population dynamics of vector mosquitoes, but it can also be used to control vector-borne diseases. Mosquito vectors that belong to several genera such as Anopheles, Aedes, and Culex play a crucial role in the transmission of malaria, dengue, chikungunya, Zika, and elephantiasis diseases worldwide. We tested the efficacy of two commercial-grade oviposition attractant formulations that were developed for the container-inhabiting Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus mosquitoes present in urban or semi-urban environments. These attractants can lure gravid females. Field trials were conducted in residential yards during a post-rainy season in September and October. Our data showed considerable efficacy for both attractants. Aedes-attractant collected 1.6-fold more larvae (101.2 ± 10.5 larvae/trap) than the control, and Culex-attractant collected 1.27-fold more larvae (151.2 ± 12.5 larvae/trap) than the control, resulting in 0.8 and 0.7 oviposition attraction indices (OAIs), respectively. Regression analysis indicated that the Aedes-attractant was more stable than the Culex-attractant. Location and time did not alter the efficacy of these attractants. Our experiment suggests that these attractants can be used for the development of species-specific gravid traps to detect, estimate, and control the mosquito population in urban and semi-urban areas.


Assuntos
Aedes/efeitos dos fármacos , Febre de Chikungunya/prevenção & controle , Culex/efeitos dos fármacos , Dengue/prevenção & controle , Malária/prevenção & controle , Oviposição/efeitos dos fármacos , Infecção por Zika virus/prevenção & controle , Aedes/fisiologia , Animais , Febre de Chikungunya/transmissão , Culex/fisiologia , Dengue/transmissão , Feminino , Humanos , Larva , Malária/transmissão , Controle de Mosquitos , Mosquitos Vetores/efeitos dos fármacos , Mosquitos Vetores/fisiologia , Infecção por Zika virus/transmissão
16.
An Acad Bras Cienc ; 91(2): e20180516, 2019 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-30758393

RESUMO

In order to evaluate the effect of rosemary oil and micro mineral sources on the performance and egg quality of laying hens, 288 hens were used and distributed in a completely randomized design using a 2x3 factorial (mineral sources x rosemary oil) with six different diets and six replications. Diets were formulated containing inorganic or organic minerals, with or without added rosemary oil (100 and 200 mg kg-1). The treatments showed interaction for average egg weight, yolk color, albumen and yolk percentage, with significant results from the use of organic minerals compared to inorganic minerals. The addition of 200 mg kg-1 rosemary oil in diets improved laying rate, egg mass, specific gravity, number of pores on the shell when compared to other treatments. In conclusion, the use of 200 mg kg-1 of rosemary oil improves the performance of red laying hen eggs. The association between organic minerals and 100 mg kg-1 rosemary oil in laying hen diets increases yolk color and percentage of albumen. The use of organic minerals is superior to inorganic minerals as to improve the quality of eggs, increasing average egg weight, yolk color and percentage of albumen.


Assuntos
Ração Animal , Suplementos Nutricionais/análise , Minerais/análise , Óleos Voláteis/administração & dosagem , Oviposição/efeitos dos fármacos , Óleos Vegetais/administração & dosagem , Criação de Animais Domésticos , Fenômenos Fisiológicos da Nutrição Animal , Animais , Brasil , Galinhas , Casca de Ovo/efeitos dos fármacos , Gema de Ovo/efeitos dos fármacos , Feminino
17.
Poult Sci ; 98(6): 2500-2508, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30668840

RESUMO

This study was conducted to evaluate the effects of L-glutamic acid (Glu) on the productive performance, eggshell quality, bone characteristics, and morphologic parameters of laying hens. Two hundred and forty 53-wk-old Hy-Line W36 laying hens were randomly allocated into 5 treatments, 6 replicates, and 8 birds each. The experimental period was 16 wk. The treatments consisted of a Basal diet (Glu calculated at 2.68%) and 4 L-glutamic acid inclusion levels: 2.88, 3.08, 3.28, and 3.48%. Glu inclusion levels in the hens diet had an increasing linear effect (P < 0.05) on eggshell Ca concentration and bone (tibiotarsus) strength index, and a decreasing linear effect (P < 0.05) on the Seedor index. Serum biochemistry results for total and ionic Ca, inorganic P, and alkaline phosphatase were affected by blood collection time (04:00 Pm, 03:00 Am, and 12:00 Pm) but not by the treatments. Jejunum morphometric variables were not influenced by the treatments except for crypt depth, which demonstrated a quadratic effect (P < 0.05). However, proliferating cell nuclear antigen qualitative immunohistochemical analysis of the jejunum showed more positive nuclei in the villus with the addition of Glu. Both with the basal diet and the lowest Glu inclusion treatment, positive nuclei were observed in the crypts and at the base of the villus, while in the treatments with higher Glu levels, positive cells were common all along the villus mucosa, including its extremity. In conclusion, diets formulated with increased levels of Glu had beneficial effects on eggshell Ca concentration, tibiotarsus structure, and proliferative activity of the jejunum of 69-wk-old laying hens. Therefore, dietary L-glutamic acid can be considered an alternative additive to improve bone characteristics in the productive phase of laying hens.


Assuntos
Ração Animal/análise , Osso e Ossos/efeitos dos fármacos , Ácido Glutâmico/farmacologia , Jejuno/efeitos dos fármacos , Oviposição/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição Animal , Animais , Osso e Ossos/anatomia & histologia , Galinhas , Dieta/veterinária , Casca de Ovo/química , Casca de Ovo/efeitos dos fármacos , Feminino , Ácido Glutâmico/administração & dosagem , Jejuno/anatomia & histologia , Fenômenos Mecânicos
18.
Parasitol Res ; 118(2): 505-516, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30617587

RESUMO

Schistosomiasis is a tropical neglected disease whose socioeconomic impact is surpassed only by malaria. Until recently, praziquantel (PZQ) has been the only available drug, raising concerns that tolerant/resistant strains may appear. Since the discovery of the schistosomicidal potential of artemisinin (ART), new derivatives have been produced and evaluated. In this work, we evaluated the activity of ART derivatives against Schistosoma mansoni, both in vitro and in vivo. In the in vitro assay, worm survival, oviposition, and morphological alterations were evaluated. Further analysis of morphological alterations and membrane integrity was conducted using scanning electron microscopy and a cell-permeable, benzimidazole dye (Hoescht 33258) that binds to the minor groove of double stranded DNA. For the in vivo assay, artesunic acid (AcART) and dihydroartemisinin acetate (AcDQHS) were selected, since they showed the best in vitro results. Infected mice treated 21, 45, or 60 days post-infection (dpi), with a concentration of 100 mg/kg of either AcART or AcDQHS, showed a significant worm reduction (particularly in females), fewer eggs eliminated in feces, and a decrease of immature eggs in the intestinal tissues. Our results indicate that AcART and AcDQHS have some schistosomicidal activity against juvenile and adult stages of S. mansoni.


Assuntos
Artemisininas/farmacologia , Artemisininas/uso terapêutico , Schistosoma mansoni/efeitos dos fármacos , Esquistossomicidas/farmacologia , Esquistossomicidas/uso terapêutico , Animais , Linhagem Celular , Fezes/parasitologia , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Oviposição/efeitos dos fármacos , Schistosoma mansoni/ultraestrutura , Esquistossomose mansoni/tratamento farmacológico
19.
Acta Trop ; 191: 228-238, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30653943

RESUMO

The dispersal of insects is determinant in the colonization of new areas and the propagation of insecticide resistance. Nutritional status and reproductive characteristics determine the colonization capacity after the dispersal event. Studies about of the effects of dispersal on reproduction in triatomines are few and none in resistant insects. The aim was to determine the effects of nutritional state and dispersal on the subsequent reproductive potential in Triatoma infestans (Klug, 1834) susceptible and resistant to deltamethrin. Three nutritional states were obtained with the number of feeds (NF) offered (0, 1 or 2). The resistant females were evaluated only with NF1. The experimental arena was 10 m long and contained two shelters. Groups of 30 virgin females of each NF were released in one of the shelters and were able to move during 3 days/nights. Females without possibility of dispersal were the controls. The reproductive parameters were determined on the couples between the experimental females and males from the breeding. The results showed that most of the females dispersed by walking. The dispersal had effects on the reproduction of the deltamethrin-susceptible females and this depended on the number of feeds. Fecundity, fertility and the proportion of females that oviposited were higher in females dispersed with two feeds but was lower in females dispersed with less feeds. In addition, the effect of the dispersal on the reproduction and the life time also depended of the toxicological phenotype. The resistant insect oviposited in higher proportion and showed greater fecundity and more weeks of life when they dispersed that when they did not do it, and was opposite to that observed in susceptible ones. Finally, the resistance to insecticide had an effect on the reproduction and the life span and this effect depended on whether the insects dispersed or not.


Assuntos
Resistência a Inseticidas/efeitos dos fármacos , Inseticidas/toxicidade , Nitrilos/toxicidade , Estado Nutricional/efeitos dos fármacos , Ninfa/efeitos dos fármacos , Piretrinas/toxicidade , Reprodução/efeitos dos fármacos , Triatoma/efeitos dos fármacos , Animais , Feminino , Fertilidade/efeitos dos fármacos , Masculino , Oviposição/efeitos dos fármacos
20.
Sci Total Environ ; 651(Pt 2): 2420-2423, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30336431

RESUMO

Microplastic (MP) pollution continues to proliferate in freshwater, marine and terrestrial environments, but with their biotic implications remaining poorly understood. Biotic interactions such as predation can profoundly influence ecosystem structuring, stability and functioning. However, we currently lack quantitative understandings of how trophic interaction strengths and associated behaviours are influenced by MP pollution, and how transference of MPs between trophic levels relates to consumptive traits. We also lack understanding of key life-history effects of MPs, for example, reproductive strategies such as oviposition. The present study examines the predatory ability of non-biting midge larvae, Chaoborus flavicans, towards larvae of Culex pipiens mosquitoes when the latter are exposed to MPs, using a functional response (FR) approach. Transfer of MPs occurred from larval mosquitoes to larval midges via predation. Microplastics transfer was significantly positively related to predation rates. Predation by C. flavicans followed a Type II FR, with average maximum feeding rates of 6.2 mosquito larvae per hour. These and other FR parameters (attack rates and handling times) were not significantly influenced by the presence of MPs. Further, C. pipiens adults did not avoid ovipositing in habitats with high concentrations of MPs. We thus demonstrate that MPs can move readily through freshwater food webs via biotic processes such as predation, and that uptake correlates strongly with consumption rates. Further, as MPs do not deter adult mosquitoes from ovipositing, our experiments reveal high potential for MP exposure and transference through ecosystems.


Assuntos
Dípteros/fisiologia , Poluentes Ambientais/efeitos adversos , Cadeia Alimentar , Oviposição , Plásticos/efeitos adversos , Animais , Culex/efeitos dos fármacos , Culex/crescimento & desenvolvimento , Culex/fisiologia , Dípteros/efeitos dos fármacos , Dípteros/crescimento & desenvolvimento , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/fisiologia , Oviposição/efeitos dos fármacos
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