Consulta: subjectFacets:"Lethal concentration"
Registros recuperados: 9
Data/hora: 13/06/2024 04:07:36

Tolerance of disease‐vector mosquitoes to brackish water and their osmoregulatory ability
Provedor de dados: 5
Autores: Kengne, Pierre; Charmantier, Guy; Blondeau‐bidet, Eva; Costantini, Carlo; Ayala, Diego.
Salinity tolerance is an important trait that governs the ecology of disease‐vector mosquitoes by determining their choice of larval habitat, and consequently their ecological and geographical distribution. Here, we used laboratory strains to determine the osmotic responses of larvae of obligate freshwater disease‐vector mosquitoes (Aedes aegypti, Aedes albopictus, Anopheles coluzzii, An. gambiae, Culex pipiens, and Cx. quinquefasciatus) and assessed their relationship with salinity tolerance. First, we analyzed the acute dose–mortality response of fourth‐instar larvae to salinity; then, we measured their hemolymph osmolality after 24‐h exposure to varying salinities. We found that Ae. albopictus was the most tolerant species, followed by An. coluzzii,...
Tipo: Text
Palavras-chave: Adaptation; Aedes; Anopheles; Culex; Hemolymph osmolality; Lethal concentration; Mosquitoes; Osmoregulation; Salinity tolerance.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00585/69744/67634.pdf

Toxicity of neem oil to Bemisia tabaci biotype B nymphs reared on dry bean
Provedor de dados: 86
Autores: Pinheiro,Patricia Valle; Quintela,Eliane Dias; Oliveira,Jaison Pereira de; Seraphin,José Carlos.
The objective of this work was to determine the most susceptible nymphal stage of Bemisia tabaci biotype B to neem (Azadirachta indica A. Juss.) oil applied to dry bean (Phaseolus vulgaris L.) in a screenhouse. A solution of commercial oil (Dalneem) extracted from neem seeds was sprayed directly on each nymphal instar at 0, 0.1, 0.25, 0.5, 1 and 2% concentrations for lethal concentration (LC) determination, and at 0, 0.5 and 1% concentrations for lethal time (LT) determination. The number of living and dead nymphs was recorded five days after spraying for LC determination, and daily during six days for LT determination. The LC50 estimated for fourth instar nymphs occurred at 0.56% concentration. For all instars, LC50 and LC95 were estimated at 0.32 and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Azadirachta indica; Phaseolus vulgaris; Immature stages; Lethal concentration; Whitefly.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2009000400004

Peppermint essential oil as an anesthetic for and toxicity to juvenile silver catfish
Provedor de dados: 86
Autores: Spanghero,Diogo Bessa Neves; Spanghero,Emília Carolina Alencar de Medeiros; Pedron,Janaína dos Santos; Chagas,Edsandra Campos; Chaves,Francisco Célio Maia; Zaniboni-Filho,Evoy.
Abstract: The objective of this work was to evaluate peppermint (Mentha piperita) essential oil toxicity to and potential as an anesthetic for juvenile silver catfish (Rhamdia quelen). To determine the lethal concentration at 4 hours (LC50-4h), 210 fish (3.08±0.8 g and 7.59±0.67 cm) were exposed to 0, 20, 50, 80, 110, and 140 mg L-1 essential oil. To evaluate the anesthetic potential, nine fish were individually exposed to each oil concentration (50, 80, 110, and 140 mg L-1) used. Water quality parameters were controlled. The mortality rate and the severity and extent of the gill injuries of silver catfish juveniles at 4 hours of exposure increased with increasing peppermint essential oil concentrations, with LC50-4h estimated to be 75.06 mg L-1. The main...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mentha piperita; Rhamdia quelen; Anesthesia; Gill; Histology; Lethal concentration.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2019000101102

Toxicity and repellency of essential oils in the management of Sitophilus zeamais
Provedor de dados: 91
Autores: Araújo,Alice M. N. de; Oliveira,José V. de; França,Solange M.; Navarro,Daniela M. do A. F.; Barbosa,Douglas R. e S.; Dutra,Kamilla de A.
ABSTRACT This study had the following objectives: to identify and quantify the constituent compounds of essential oils from Cymbopogon winterianus Jowitt, Eucalyptus globulus Labill., Eucalyptus staigeriana F. Muell. ex F.M. Bailey, Foeniculum vulgare Mill., Ocimum basilicum L., Ocimum gratissimum L., and Piper hispidinervum C. DC., investigate their toxicity and repellency to S. zeamais and evaluate the toxicity of P. hispidinervum to immature S. zeamais. Individual tests for each essential oil were conducted with a completely randomized design with five concentrations for each oil and four replicates. Gas chromatography-mass spectrometry revealed the presence of citronellal in C. winterianus, 1,8-cineole in E. globulus, limonene in E. staigeriana,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Alternative fumigant; Bioactivity; Lethal concentration; Maize weevil; Natural insecticide.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662019000500372

Acetylcholinesterase enzyme activity in carp brain and muscle after acute exposure to diafuran
Provedor de dados: 63
Autores: Golombieski,Jaqueline Ineu; Marchesan,Enio; Camargo,Edinalvo Rabaioli; Salbego,Joseânia; Baumart,Joele Schmitt; Loro,Vania Lucia; Machado,Sérgio Luiz de Oliveira; Zanella,Renato; Baldisserotto,Bernardo.
Sublethal adverse effects may result from exposure of aquatic organisms to insecticides at environmentally relevant concentrations. Fingerlings of the common carp (Cyprinus carpio, Linnaeus, 1758), grass carp (Ctenopharyngodon idella, Valenciennes, 1844), and bighead carp (Aristichthys nobilis, Richardson, 1845) were exposed to diafuran, an insecticide widely used during rice cultivation in Southern Brazil. The aim of this study was to verify the relationship between the lethal concentration (LC50) of diafuran and the acetylcholinesterase (AChE) activity in brain and muscle tissues of these species as a possible early biomarker of exposure to this insecticide. LC50 was determined for fish exposed to diafuran concentrations during 96 h (short term): common...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cyprinus carpio; Ctenopharyngodon idella; Aristichthys nobilis; Pesticide; Lethal concentration.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162008000400003

ประสิทธิภาพของสารเคมีป้องกันกำจัดแมลงกลุ่มใหม่ต่อการควบคุมเพลี้ยกระโดดสีน้ำตาล (Brown planthopper, Nilaparvata lugens (Stål)) และผลกระทบต่อมวนเขียวดูดไข่ (Mirid bug , Cyrtorhinus lividipennis Reuter)
Provedor de dados: 106
Autores: Sukanya Arunmit; Wantana Sriratanasak; Jintana Chaiwong.
Brown planthopper (BPH) is a major insect pest of irrigated rice cultivation areas in lower north, central and northeast Thailand. The field experiments were conducted to evaluate the efficacy of nine insecticides to control BPH in farmers’ fields at Suphan Buri, Nakhonayok and Ubon Ratchathani provinces. The results showed that the sulfoxaflor 50 % WG and pymetrozine 50 % WG were the most effective insecticides. The ratios of BPH/mirid bug (MB) in the buprofezin and pymetrozine fields were lower than other fields, which may indicate the less toxicity to MB compared with other insecticides. Moreover, toxicity of each insecticide to MB was investigated using a leaf dipping method and the result indicated that pymetrozine 50 % WG was the lowest toxicity to...
Tipo: Collection
Palavras-chave: Rice; Insecticides; Efficacy of insecticides; Side-effect of insecticides; ฺBrown planthopper; Mirid bug; Suphan Buri province; Nakhonayok province; Ubon Ratchathani province; Lethal concentration; Side effects; ข้าว; สารเคมีป้องกันกำจัดแมลง; ประสิทธิภาพยาฆ่าแมลง; ผลกระทบยาฆ่าแมลง; เพลี้ยกระโดดสีน้ำตาล; มวนเขียวดูดไข่; สุพรรณบุรี; นครนายก; อุบลราชธานี; ระดับความเป็นพิษ; ผลข้างเคียงของยา.
Ano: 2015
URL: http://anchan.lib.ku.ac.th/agnet/handle/001/5859

Acute toxicity and histopathology in ornamental fish amazon bluespotted corydora (Corydoras melanistius) exposed to formalin
Provedor de dados: 42
Autores: Santos,Rudã F.B.; Dias,Henrique M.; Fujimoto,Rodrigo Y.
The objective of this work was to evaluate the acute toxicity of formalin and histopathological effects on the Amazon ornamental fish, bluespotted coridora (Corydoras melanistius). A randomized design was used, with ten concentrations of formalin (40%) (0, 3, 6, 12, 25, 50, 100, 150, 200 and 250mg.L-1) with four replicates and five fish per container (3L) in static system for 96 hours. The moribund fish were killed and fixed in 10% formalin to proceed the histopathological analysis of gill, liver and kidney. At the end of this experiment the following mortality rates (%) were obtained in increasing order of exposure: 0, 0, 0, 0, 0, 65, 85, 100, 100 and 100%. The lethal concentration 50% (LC50-96h (I)) estimated was 50.76 mg.L-1 with regression of y =...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Lethal concentration; Corydora; Formaldehyde; Toxicity; Histology; Amazon.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652012000400014

Acute toxicity of sodium metabisulphite on mangrove crab Ucides cordatus (Decapoda, Ucididae)
Provedor de dados: 42
Autores: Pedale,Adriana B.; Fujimoto,Rodrigo Y.; Santos,Rudã F.B.; Abrunhosa,Fernando A.
The sodium metabisulphite salt is usually used in shrimp culture to prevent black spot. Unfortunately the toxicological effect of this xenobiotic in decapod crabs is unknown. Thus, the present study aims to investigate the sodium metabisulphite LC50 - 96 h in the mangrove species Ucides cordatus. Crabs were collected in the tidal creek margins in Bragança estuarine and were submitted to preliminary test (screening) and posterior definitive test. Crabs were exposed in five different concentrations and a control group in five replicates, two crabs per recipient (5 L) during 96 hours. A negative correlation was observed to sodium metabisulphite concentration in relation to dissolved oxygen and pH. At the end of the experiment were obtained the following...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Shrimp culture; Environmental impact; Metabisulphite; Lethal concentration; Neotropical species.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652012000400015

Selection of Entomopathogenic Nematodes against Dalaca pallens (Lepidoptera: Hepialidae)
Provedor de dados: 117
Autores: Maldonado,Alexis; Merino,Loreto; France,Andrés.
Dalaca pallens (Blanchard) is a pest with great impact on grassland production in Chile. The objective of this research was to evaluate the use of entomopathogenic nematodes (EPN) against D. pallens larvae. Twenty EPN isolates, collected along Chile, were used for nematode selection. The experimental unit consisted of five 50-mL plastic vials filled with Nothofagus dombeyi sawdust and inoculated with 40 dauers per vial. The experimental design was a completely randomized with four replicates per treatment. The results showed that isolate QU N3 (Steinernema australe) and QU N13 (Steinernema unicornum) produced the highest mortality, with 100 and 95% respectively and no differences (P &lt; 0.001) between both. Later, these two isolates were used to calculate...
Tipo: Journal article
Palavras-chave: Biological control; Lethal concentration.
Ano: 2012
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392012000200006