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Biodegradation Jul 2009A chlorpyrifos-methyl (CM) degrading bacterium (designated strain KR100) was isolated from a Korean rice paddy soil and was further tested for its sensitivity against...
A chlorpyrifos-methyl (CM) degrading bacterium (designated strain KR100) was isolated from a Korean rice paddy soil and was further tested for its sensitivity against eight commercial antibiotics. Based on morphological, biochemical, and molecular characteristics, this bacterium showed greatest similarity to members of the order Burkholderiales and was shown to be most closely related to members of the Burkholderia cepacia group. Strain KR100 hydrolyzed CM to 3,5,6-trichloro-2-pyridinol (TCP) and utilized TCP as the sole source of carbon for its growth. The isolate was also able to degrade chlorpyrifos, dimethoate, fenitrothion, malathion, and monocrotophos at 300 microg/ml but diazinon, dicrotophos, parathion, and parathion-methyl at 100 microg/ml. The ability to degrade CM was found to be encoded on a single plasmid of approximately 50 kb, pKR1. Genes encoding resistance to amphotericin B, polymixin B sulfate, and tetracycline were also located on the plasmid. This bacterium merits further study as a potential biological agent for the remediation of soil, water, or crop contaminated with organophosphorus compounds because of its greater biodegradation activity and its broad specificity against a range of organophosphorus insecticides.
Topics: Burkholderia; Chlorpyrifos; Chromatography, Gas; Microscopy, Electron, Scanning; Plasmids; Pyridones
PubMed: 19082866
DOI: 10.1007/s10532-008-9238-7 -
Talanta Oct 1997A simple, sensitive and rapid differential pulse polarographic method has been developed for the quantitative determination of organophosphorus pesticides such as...
A simple, sensitive and rapid differential pulse polarographic method has been developed for the quantitative determination of organophosphorus pesticides such as dicrotophos, crotoxyphos and chlorfenvinphos in agricultural formulations in universal buffers of a pH range 2.0-12.0. The sample is treated with ethanol to facilitate the dissolution of these pesticides. Both standard addition and calibration methods can be used for the analyses. The lower detection limits are 1.25x10(-9), 1.05x10(-9) and 1.0x10(-9) M, respectively. The method can be applied successfully to determination of these pesticides in grains and soil.
PubMed: 18966927
DOI: 10.1016/S0039-9140(97)00081-7 -
Journal of Toxicology and Environmental... 2008The toxicity of 10 organophophorus (OP) insecticides-acephate, dimethoate, dichlorvos, dicrotophos, monocrotophos, methamidophos, phosphamidon, omethoate, phosdrin, and... (Comparative Study)
Comparative Study
The toxicity of 10 organophophorus (OP) insecticides-acephate, dimethoate, dichlorvos, dicrotophos, monocrotophos, methamidophos, phosphamidon, omethoate, phosdrin, and trichlorfon-was evaluated in Caenorhabditis elegans using lethality, movement, and acetylcholinesterase (AChE) activity as the endpoints after a 4-hr- exposure period. The OP insecticides tested showed LC50 values ranging from 0.039 mM (for dichlorovs) to 472.8 mM (for methamidophos). The order of toxicity for lethality and movement was not significantly different when tested using the rank order correlation coefficient. AChE activity was markedly affected by all the OP insecticide exposures that caused significant inhibition in movement, indicating that the mechanism of toxicity of OP insecticides in C. elegans is the same as in higher animals. All OP insecticides induced greater than 50% inhibition of AChE at the lowest tested OP insecticide concentration resulting in inhibition in movement. While a significant correlation was evident between LC50 values in C. elegans and the LD50 values in rats for the 10 OP insecticides studied, a correlation was not evident between EC50 values in C. elegans and LD50 values in rats. Overall, the two endpoints, LC50 and movement, were more reliable and easier to perform than measurement of AChE activity in C. elegans for determining the toxicity of OP insecticides. Further, ranking of these endpoints with respect to the OP insecticides studied indicates that these parameters in C. elegans are predictive of OP insecticides mammalian neurotoxicity.
Topics: Acetylcholinesterase; Animal Testing Alternatives; Animals; Behavior, Animal; Caenorhabditis elegans; Cholinesterase Inhibitors; Dose-Response Relationship, Drug; Endpoint Determination; Insecticides; Lethal Dose 50; Longevity; Motor Activity; Organophosphorus Compounds; Toxicity Tests
PubMed: 18569613
DOI: 10.1080/15287390801989002 -
Journal of Economic Entomology Jun 2006Susceptibility of the southern green stink bug, Nezara viridula (L.) (Heteroptera: Pentatomidae), and its endoparasitoid Trichopoda pennipes (F.) (Diptera: Tachinidae)...
Susceptibility of the southern green stink bug, Nezara viridula (L.) (Heteroptera: Pentatomidae), and its endoparasitoid Trichopoda pennipes (F.) (Diptera: Tachinidae) to acetamiprid, cyfluthrin, dicrotophos, indoxacarb, oxamyl, and thiamethoxam was compared in residual and oral toxicity tests. In the residual toxicity test, cyfluthrin, dicrotophos, and oxamyl were highly toxic to N. viridula. Thiamethoxam was moderately toxic to these insects. Each of the four insecticides was highly toxic to T. pennipes after prolonged tarsal contact with dried residues of these chemicals. In the oral toxicity test, where N. viridula fed on food covered with insecticide residues, none of the insecticides were toxic to adults of this stink bug, but acetamiprid, dicrotophos, and thiamethoxam were moderately toxic to the nymphs. In the oral toxicity test, where N. viridula fed on a gel-food containing insecticides, cyfluthrin, dicrotophos, oxamyl, and thiamethoxam were highly toxic to this stink bug. In an oral toxicity test using contaminated sugar water, all of the insecticides were highly toxic to T. pennipes. Because insecticides were as toxic, or more toxic, to T. pennipes than to N. viridula, it is extremely important to conserve this parasitoid by applying these insecticides for control of southern green stink bugs only when the pest reaches economic threshold.
Topics: Animals; Diptera; Female; Heteroptera; Host-Parasite Interactions; Insecticides; Pest Control, Biological; Pesticide Residues; Predatory Behavior
PubMed: 16813294
DOI: 10.1603/0022-0493-99.3.648 -
Journal of the Medical Association of... Sep 2005The authors report 2 cases of organophosphate poisoning which developed intermediate syndrome. The first case was a man who took an organophosphate insecticide,...
The authors report 2 cases of organophosphate poisoning which developed intermediate syndrome. The first case was a man who took an organophosphate insecticide, monocrotophos, and developed severe organophosphate poisoning. Respiratory support was needed. He was treated with atropine and 2-PAM. Weakness of neck muscles, proximal limb and respiratory muscle developed in the 3rd day after ingestion. By supportive treatment and careful monitoring, however, he recovered after 11 days of the poisoning. The second case was a lady who took dicrotophos. She developed severe organophosphate poisoning for which respiratory support was also needed High dose of atropine, but without 2-PAM, was administered. She developed bulbar palsy, proximal muscle and respiratory weakness 3 day after the ingestion. Ventilation support was needed for 13 days before weaning was successful. This report did not support an efficacy of pralidoxime (2-PAM) in alleviation of the intermediate syndrome, but aims to alert physicians to recognize the intermediate syndrome for which adequate respiratory care is the crucial key for its management.
Topics: Adult; Atropine; Female; Humans; Insecticides; Male; Muscle Weakness; Organophosphate Poisoning; Paralysis; Pralidoxime Compounds; Respiratory Insufficiency; Syndrome; Thailand; Time Factors
PubMed: 16536121
DOI: No ID Found -
Journal of Economic Entomology Jun 2005Certain neonicotinoids are used in cotton, Gossypium hirsutum (L.), to control various piercing-sucking pests. We conducted field studies using three neonicotinoids...
Certain neonicotinoids are used in cotton, Gossypium hirsutum (L.), to control various piercing-sucking pests. We conducted field studies using three neonicotinoids (acetamiprid, thiamethoxam, and imidacloprid) and an organophosphate (dicrotophos) to assess the activity of these insecticides against nontarget arthropods, particularly predators, and to determine the potential economic consequences of such activity. Mortality among populations of the big-eyed bug, Geocoris punctipes (Say), and the red imported fire ant, Solenopsis invicta Buren, was highest after thiamethoxam and dicrotophos treatments. Numbers of arachnids were consistently lower after dicrotophos treatments, whereas none of the neonicotinoids caused appreciable mortality. Total predators in pooled data from five separate studies revealed that numbers, compared with untreated plots, were reduced by -75% in dicrotophos, 55-60% in thiamethoxam, and only 30% in both acetamiprid and imidacloprid plots. Acetamiprid and thiamethoxam exhibited significant mortality against field-deposited eggs of bollworm, Helicoverpa zea (Boddie). Both thiamethoxam and dicrotophos plots exhibited bollworm numbers that were approximately three times higher than treatment thresholds (three per 100 plants), whereas numbers in untreated plots were below threshold levels. In one study on Bt cotton, a significant negative correlation was observed between numbers of predators and bollworm larvae. Results demonstrated that neonicotinoids differ in activity against predaceous arthropods and bollworm eggs and that high predator mortality can result in resurgence of bollworm larvae and additional insecticide costs.
Topics: Animals; Arthropods; Gossypium; Heterocyclic Compounds, 1-Ring; Insect Control; Insecticides; Lepidoptera; Organophosphorus Compounds; Ovum
PubMed: 16022310
DOI: 10.1603/0022-0493-98.3.814 -
Journal of Economic Entomology Feb 2005Adult brown, Euschistus servus (Say); green, Acrosternum hilare (Say); and southern green, Nezara viridula (L.), stink bugs were collected from soybean, Glycine max (L.)... (Comparative Study)
Comparative Study
Adult brown, Euschistus servus (Say); green, Acrosternum hilare (Say); and southern green, Nezara viridula (L.), stink bugs were collected from soybean, Glycine max (L.) Merr., in fall 2001 and 2002 near Stoneville, MS, and Eudora, AR. A glass-vial bioassay was used to determine LC50 values for the three species of stink bugs for the pyrethroids bifenthrin, cypermethrin, cyfluthrin, lambda-cyhalothrin, and permethrin, and the organophosphates acephate, dicrotophos, malathion, and methyl parathion. Results confirmed findings of other researchers that the brown stink bug was less susceptible to pyrethroid and organophosphate insecticides than were green and southern green stink bugs. The susceptibility of all three stink bug species to the insecticides tested was very similar at both test locations. The study established baseline insecticide mortality data from two locations in the mid-South for three stink bug species that are pests of soybean and cotton, Gossypium spp. Data from the tests are valuable for future use in studies on resistance and in resistance monitoring programs.
Topics: Animals; Gossypium; Heteroptera; Insect Control; Insecticide Resistance; Insecticides; Organophosphates; Pyrethrins; Glycine max; Species Specificity
PubMed: 15765680
DOI: 10.1603/0022-0493-98.1.177 -
Pest Management Science Jan 2005An equine disease now known as mare reproductive loss syndrome (MRLS) struck the Ohio Valley in 2001-2002 causing thousands of foal abortions and enormous economic loss....
An equine disease now known as mare reproductive loss syndrome (MRLS) struck the Ohio Valley in 2001-2002 causing thousands of foal abortions and enormous economic loss. Evidence that pregnant mares' exposure to Eastern tent caterpillars Malacosoma americanum (F) induces MRLS created an urgent call for control measures suitable for use on horse farms. We surveyed egg mass distribution and monitored emergence in wild cherry trees, and evaluated reduced-risk treatment strategies including foliage sprays, trunk injections, winter egg mass treatments and barrier sprays to intercept larvae entering pastures. Egg masses were concentrated in the lower canopy, on exposed sides of trees. Larval emergence began in mid-March. Emergence was prolonged (3-4 weeks) in 2002, a typically cool spring, but more synchronized in warmer 2003. Winter treatment of egg masses with bifenthrin or permethrin in a penetrating solvent prevented emergence, but 3% horticultural oil was ineffective for that purpose. Insecticidal soap or oil sprayed directly on neonates gave relatively poor control. Bifenthrin and spinosad were effective as foliage sprays against all instars, their field-weathered residues active for at least 7 days. Bacillus thuringiensis Berliner var kurstaki controlled neonates within 3 days but was less active against late instars, with shorter residual action than bifenthrin or spinosad. Larvae did not avoid insecticide-treated leaves. Trunk microinjection of cherry trees with dicrotophos was effective against all instars, whereas microinjection with milbemectin or abamectin gave poor or inconsistent control. Trunk injection with emamectin benzoate also was effective. Dry permethrin residues controlled late instars crawling in pasture grass for at least 7 days. Factors complicating M americanum management on horse farms are discussed.
Topics: Abortion, Veterinary; Agriculture; Animals; Female; Horse Diseases; Horses; Insect Control; Insecticides; Larva; Moths; Ovum; Pregnancy; Risk Factors; Time Factors; Trees
PubMed: 15593079
DOI: 10.1002/ps.958 -
Bulletin of Environmental Contamination... Oct 2004
Topics: Acetylcholinesterase; Adipose Tissue; Animals; Arkansas; Body Weight; Cholinesterase Inhibitors; Cholinesterase Reactivators; Cholinesterases; Crops, Agricultural; Environmental Monitoring; Gossypium; Insecticides; Malathion; Organophosphorus Compounds; Organothiophosphorus Compounds; Passeriformes; Phosphoramides; Pralidoxime Compounds
PubMed: 15389333
DOI: 10.1007/s00128-004-0480-3 -
Journal of Economic Entomology Jun 2004Susceptibility of the brown stink bug, Euschistus serous (Say), and the spined soldier bug, Podisus maculiventris (Say), to acetamiprid, cyfluthrin, dicrotophos,... (Comparative Study)
Comparative Study
Susceptibility of the brown stink bug, Euschistus serous (Say), and the spined soldier bug, Podisus maculiventris (Say), to acetamiprid, cyfluthrin, dicrotophos, indoxacarb, oxamyl, and thiamethoxam, was compared in residual and oral toxicity tests. Generally, susceptibility of P. maculiventris to insecticides was significantly greater than or not significantly different from that of E. servus. Cyfluthrin and oxamyl were more toxic to the predator than to E. servus in residual and feeding tests, respectively. Dicrotophos is the only compound that exhibited both good residual and oral activity against E. servus, but even this toxicant was more toxic to the predator than to the pest in oral toxicity tests. Feeding on indoxacarb-treated food caused high mortality for both nymphs and adults of P. maculiventris. In contrast, E. servus was unaffected by feeding on food treated with this compound. Insecticide selectivity to P. maculiventris was detected only with acetamiprid for adults in residual toxicity tests and for nymphs in oral toxicity tests. Because insecticide selectivity to P. maculiventris was limited, it is extremely important to conserve P. maculiventris in cotton fields by applying these insecticides for control of brown stink bugs only when the pest reaches economic threshold.
Topics: Animals; Gossypium; Heteroptera; Insect Control; Insecticides; Organophosphorus Compounds
PubMed: 15279256
DOI: 10.1603/0022-0493(2004)097[0800:cosope]2.0.co;2