Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Environ Sci Pollut Res Int ; 31(31): 43927-43940, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38913262

RESUMO

The caterpillar Anticarsia gemmatalis (Lepidoptera: Noctuidae) is a prevalent pest in soybean plantations, managed using both natural and synthetic chemical products. However, the emergence of resistance in some populations emphasizes the need to explore alternative insecticides. Flupyradifurone, a neurotoxic insecticide, has not been previously used for controlling A. gemmatalis. This study evaluated the potential of flupyradifurone in the management of A. gemmatalis. Initially, the toxicity and anti-feeding effects, as well as histopathological and cytotoxic impacts, of flupyradifurone on A. gemmatalis were evaluated. Subsequently, the indirect effects of flupyradifurone on the midgut and fat body of the predator Podisus nigrispinus (Hemiptera: Pentatomidae) were verified. The results indicate the susceptibility of caterpillars to flupyradifurone, with an LC50 of 5.10 g L-1. Furthermore, the insecticide adversely affects survival, induces an anti-feeding response, and inflicts damage on the midgut of the caterpillars. However, flupyradifurone also leads to side effects in the predator P. nigrispinus through indirect intoxication of the caterpillars, including midgut and fat body damage. While flupyradifurone demonstrates toxicity to A. gemmatalis, suggesting its potential for the chemical control of this pest, the indirect negative effects on the predator indicate the need for its controlled use in integrated pest management programs with the insecticide and the predator.


Assuntos
Inseticidas , Animais , Inseticidas/toxicidade , Larva/efeitos dos fármacos , 4-Butirolactona/análogos & derivados , 4-Butirolactona/toxicidade , Heterópteros/efeitos dos fármacos , Mariposas/efeitos dos fármacos , Lepidópteros/efeitos dos fármacos , Piridinas
2.
Sci Rep ; 10(1): 14617, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32883966

RESUMO

Plants of the genus Eucalyptus, cultivated in many countries, have great importance for the world economy. In Brazil, this culture occupies a total of 5.7 million hectares, but native and exotic insect pests can reduce its productivity. Thaumastocoris peregrinus Carpintero & Dellapé (Hemiptera: Thaumastocoridae), an exotic Australian pest, damages Eucalyptus plants. Biological control using the egg parasitoid Cleruchoides noackae Lin & Huber (Hymenoptera: Mymaridae), Heteroptera predators and entomopathogenic fungi, such as Beauveria bassiana and Metarhizium anisopliae, have potential for managing T. peregrinus. Chemical insecticides, including bifenthrin and acetamiprid + bifenthrin, also control this insect. The compatibility of chemical and biological control methods favors integrated pest management. The objective of this study was to evaluate the selectivity of commercial products based on B. bassiana, M. anisopliae and the chemical bifenthrin on the parasitoid C. noackae and its parasitism on T. peregrinus eggs. The selectivity test followed the standards recommended by the International Organization for Biological Control (IOBC). Beauveria bassiana has selectivity to parasitism as well as viability, but was slightly harmful to C. noackae adults; M. anisopliae was innocuous to adults and to the viability of the offspring of this parasitoid, but it reduced the parasitism rate; and bifenthrin did not show selectivity to this parasitoid.


Assuntos
Eucalyptus/parasitologia , Heterópteros/efeitos dos fármacos , Inseticidas , Controle Biológico de Vetores/métodos , Animais , Austrália , Beauveria , Heterópteros/microbiologia , Himenópteros , Metarhizium
3.
Chemosphere ; 261: 127720, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32721693

RESUMO

Podisus nigrispinus Dallas (Heteroptera: Pentatomidae) preys on insect pests in eucalyptus plantations where it can be exposed to insecticides used in pest control. The effect of insecticides on non-target natural enemies requires further study. The objective of the present study was to evaluate the side-effects of Bacillus thuringiensis (Bt), permethrin, tebufenozide and thiamethoxam on third instar nymphs of the predator P. nigrispinus in the laboratory. The toxicity of insecticides for this insect was determined by estimating their lethal concentrations. Podisus nigrispinus behavior after exposure to insecticides was analyzed using a video tracking system and the respiratory rate with a respirometer. Prey/nymph consumption was assessed after 24 h of starvation. The preference of P. nigrispinus nymphs, for prey treated or not with the insecticides, was evaluated in free choice tests. The insecticides Bt [LC50 = 1.10(0.83-1.46) mg mL-1], permethrin [LC50 = 0.25(0.17-0.34) mg mL-1], tebufenozide [LC50 = 5.71(4.17-7.57) mg mL-1] and thiamethoxam [LC50 = 0.04(0.02-0.06) mg mL-1] are toxic to P. nigrispinus nymphs. Bt and the insecticides tebufenozide, permethrin and thiamethoxam reduced the respiratory rate of P. nigrispinus. The insecticides permethrin, tebufenozide and thiamethoxam affect the locomotion of this insect's nymphs. Prey treated with Bt, permethrin and thiamethoxam are less preferred by P. nigrispinus. The survival of the nymphs of this predator was 93.3%, 66.7%, 56.6%, 0% and 0% in the control, tebufenozide, Bt, permethrin and thiamethoxam treatments, respectively. In addition, the reduction of prey consumption, treated with neurotoxic insecticides, reduces the predatory potential of this natural enemy. Bt and tefubenozide present low toxicity for P. nigrispinus, but the neurotoxic products have low compatibility with this natural enemy and, therefore, are not recommended, with this predator in the management of forest insect pests.


Assuntos
Comportamento Alimentar/efeitos dos fármacos , Heterópteros/efeitos dos fármacos , Inseticidas/toxicidade , Ninfa/efeitos dos fármacos , Comportamento Predatório/efeitos dos fármacos , Animais , Bacillus thuringiensis/efeitos dos fármacos , Bacillus thuringiensis/crescimento & desenvolvimento , Brasil , Eucalyptus/crescimento & desenvolvimento , Controle de Pragas , Controle Biológico de Vetores
4.
Ecotoxicol Environ Saf ; 184: 109669, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31536847

RESUMO

Cotton hosts a variety of arthropod pests requiring intensive control mostly with insecticides, which in turn may impact beneficial insects and the environment. Therefore, insect control in cotton fields preconizes the use of selective insecticides that offer pest control but conserve natural enemies. In this work, we measured the impact of recommended insecticides on the abundance of predatory insects and predation upon sentinel preys in the field. Further, the survival of four key selected predatory insects of cotton ecosystem, representing chewing and sucking feeding habits and different pest species attacked [Chrysoperla externa Hagen, Eriopis connexa (Germar), Podisus nigrispinus (Dallas) and Orius insidiosus (Say)], were assessed when exposed to the dried residues of the tested insecticides. Mortality of sentinel prey caused by natural enemies was higher in areas treated with selective insecticides relative to the non-selective ones, and most of time similar to the untreated areas. Furthermore, areas treated with non-selective insecticides experienced prolonged impact between sprays depending on the insecticide applied. Seasonal abundance of predatory insects was 2× greater in fields under selective and untreated fields compared to those under non-selective recommendation. Survival of predators exposed to the dried residues of the selective insecticides pymetrozine, chlorantraniliprole, pyriproxyfen, and cyantraniliprole were greater than when exposed to the non-selective lambda-cyhalothrin, malathion, dimethoate, and thiamethoxam. Among the non-selective insecticides, malathion and dimethoate exhibited shorter residual time compared to the thiamethoxam and lambda-cyhalothrin + thiamethoxam. Therefore, the recommendation of selective insecticides provides benefits for cotton pest management by maintaining the action of the natural enemies present in the field.


Assuntos
Besouros/efeitos dos fármacos , Gossypium/crescimento & desenvolvimento , Heterópteros/efeitos dos fármacos , Controle de Insetos/métodos , Inseticidas/farmacologia , Comportamento Predatório/efeitos dos fármacos , Animais , Ecossistema , Modelos Teóricos
5.
Ecotoxicology ; 28(7): 763-770, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31254186

RESUMO

Euschistus heros (F.) (Hemiptera: Pentatomidae) is a soybean pest in Brazil, controlled with synthetic chemical insecticides, which may be harmful to the environment and humans, as well as to select pest resistant strains. The research for new pest control strategies such as the use of plant essential oils has been increased due to the selectivity and biodegradation of these molecules. The objective was to evaluate the cytological changes in the salivary glands, fat body and midgut of E. heros exposed to different concentrations of essential oil of Piper aduncum L. (Piperales: Piperaceae), which the main compounds were identified as myristicin 30.03%, aromadendrene 9.20%, dillapiole 8.43%, α-serinene 7.31%, tridecane 6.26%, γ-elemene 4.58% and o-cymene 4.20%. The essential oil of P. aduncum was toxic for E. heros with LD50 = 36.23 mg per insect and LD90 = 50.42 mg per insect. Cytological changes such as tissue disruption, increase in mitochondria population, and glycogen and lipid depletion occur in the fat body cells, whereas salivary glands and midgut are not affected by this essential oil. Results suggest that P. aduncum essential oil causes fat body cellular stress, which may compromise some physiological processes for the insect survival.


Assuntos
Corpo Adiposo/efeitos dos fármacos , Heterópteros/efeitos dos fármacos , Óleos Voláteis/toxicidade , Piper/química , Animais , Relação Dose-Resposta a Droga , Trato Gastrointestinal/efeitos dos fármacos , Heterópteros/crescimento & desenvolvimento , Dose Letal Mediana , Ninfa/efeitos dos fármacos , Ninfa/crescimento & desenvolvimento , Óleos Voláteis/química , Glândulas Salivares/efeitos dos fármacos
6.
Sci Rep ; 9(1): 8358, 2019 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-31175321

RESUMO

Podisus nigrispinus Dallas (Heteroptera: Pentatomidae), released in biological control programs, is a predator of Lepidopteran and Coleopteran species. Lemongrass essential oil and its constituents can be toxic to this natural enemy. The major constituents of lemongrass essential oil are neral (31.5%), citral (26.1%), and geranyl acetate (2.27%). Six concentrations of lemongrass essential oil and of its citral and geranyl acetate constituents were applied to the thorax of P. nigrispinus nymphs and adults. The walking and respiratory behavior of the P. nigrispinus third-instar nymphs, treated with citral and geranyl acetate at the LD50 and LD90 doses, were analyzed with video and respirometer. The lemongrass essential oil toxicity increased from first- to fifth-instar P. nigrispinus nymphs. The P. nigrispinus respiration rates (µL de CO2 h-1/insect) with citral and geranyl acetate in the LD50 and LD90 differed. Nymphs exposed to the lemongrass essential oil and its constituents on treated surfaces presented irritability or were repelled. Podisus nigrispinus adults were tolerant to the lemongrass essential oil and its constituents, geranyl acetate and citral. The altered respiratory activity with geranyl acetate and the fact that they were irritated and repelled by citral suggest caution with regard to the use of the lemongrass essential oil and its constituents in integrated pest management incorporating this predator, in order to avoid diminishing its efficiency against the pests.


Assuntos
Cymbopogon/química , Heterópteros/efeitos dos fármacos , Óleos Voláteis/farmacologia , Terpenos/farmacologia , Animais , Heterópteros/patogenicidade , Inseticidas/química , Inseticidas/farmacologia , Ninfa/efeitos dos fármacos , Óleos Voláteis/química , Óleos de Plantas/química , Óleos de Plantas/farmacologia , Comportamento Predatório/efeitos dos fármacos , Terpenos/química
7.
PLoS One ; 13(11): e0206789, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30408828

RESUMO

BACKGROUND: The beet armyworm, Spodoptera exigua (Lepidoptera: Noctuidae), is a key insect pest of edible vegetables around the world and it is resistant to insecticide of different classes. Insecticides that are effective to this pest and selective to predator stinkbugs are required for the integrated management of S. exigua. METHODS: The toxicity of four commercial insecticide formulations azadirachtin + pyrethrin, spinosad, pyrethrin and chlorantraniliprole was tested on the target pest and their side effect were evaluated on the spined soldier bug, Podisus maculiventris (Heteroptera: Pentatomidae) through different bioassays. RESULTS: Spinosad and chlorantraniliprole were more toxic to S. exigua than to the predator P. maculiventris but opposite results were obtained for pyrethrin and azadirachtin + pyrethrin in contact toxicity bioassay. Chlorantraniliprole was the most toxic to S. exigua in oral toxicity bioassay, followed by spinosad, pyrethrin and azadirachtin + pyrethrin. Spinosad in oral toxicity bioassay was the most toxic to P. maculiventris, followed by pyrethrin, azadirachtin + pyrethrin and chlorantraniliprole. Spinosad caused irritability to the predator while pyrethrin to the pest. The insecticide repellency was not observed over the tested insect species. The synthetic insecticide chlorantraniliprole was less toxic than the natural pyrethrin, azadirachtin + pyrethrin and spinosad to the predator. CONCLUSIONS: This work provides useful information on the combination of commercial insecticides with the predator P. maculiventris to controlling S. exigua in integrated pest management (IPM) programs.


Assuntos
Heterópteros/efeitos dos fármacos , Heterópteros/patogenicidade , Inseticidas/farmacologia , Spodoptera/efeitos dos fármacos , Spodoptera/parasitologia , Animais , Comportamento Animal/efeitos dos fármacos , Cadeia Alimentar , Heterópteros/fisiologia , Controle de Insetos/métodos , Resistência a Inseticidas , Agricultura Orgânica/métodos , Spodoptera/patogenicidade , Verduras/parasitologia
8.
Ecotoxicology ; 27(6): 719-728, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29923076

RESUMO

The mirid Engytatus varians (Distant) is a promising biological control agent of the tomato borer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), one of the most destructive pests of tomato (Solanum lycopersicum L.). The effects of five insecticides commonly used on tomato crops in Brazil were evaluated on E. varians in laboratory and semifield conditions. Glass Petri dish with residues of chlorfenapyr, thiamethoxam, and abamectin caused ˃90% mortality in both stages of the predator 72 h post-treatment, except imidacloprid that caused 78% of nymphs mortality. Teflubenzuron caused 24 and 66% mortality on adults and nymphs, respectively. The offspring of females derived from treated nymphs with teflubenzuron was significantly lower than the control but not when females were treated as adults. Longevity of males derived from nymphs treated with teflubenzuron was significantly reduced, but no effects were observed on females. When males and females were treated as adults with teflubenzuron there were no effects on their longevity. In the greenhouse-aged tomato plants, the 2 h-old residues of thiamethoxam, chlorfenapyr, and abamectin caused more than 70% of mortality of third instar of E. varians at 72 h post-treatment, 12 day-old residues of all three compounds caused a mortality lower than 30%. These data suggest that teflubenzuron can be associated with releases of E. varians adults, while the use of other evaluated pesticides should be avoided in this situation. Although, the low persistence of these products indicate that their spraying and later releases of E. varians adults on tomato crops are a possible strategy to control T. absoluta.


Assuntos
Heterópteros/efeitos dos fármacos , Inseticidas/toxicidade , Comportamento Predatório/efeitos dos fármacos , Animais , Brasil , Feminino , Heterópteros/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Masculino , Mariposas/crescimento & desenvolvimento , Ninfa/efeitos dos fármacos , Ninfa/crescimento & desenvolvimento , Controle Biológico de Vetores
9.
Chemosphere ; 191: 350-356, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29049958

RESUMO

Freshwater ecosystems provide environmental conditions for many arthropod species, including pests like mosquitoes and beneficial insects. Giant water bugs, Belostoma anurum (Hemiptera: Belostomatidae), are aquatic insects that provide biological control of mosquitoes and small vertebrates in freshwater environments. However, the application of insecticides aiming to control mosquitoes can lead to insecticide exposures of aquatic predators that can result in their death or significant reductions in their behavioral abilities. Here, we assessed the susceptibilities of B. anurum to the pyrethroid insecticide deltamethrin and evaluated whether sublethal exposure to deltamethrin would change the abilities of B. anurum to prey upon larvae of Aedes aegypti (Diptera: Culicidae). Bioassays of predator performance were conducted at three prey densities (i.e., 3, 6 and 9 larvae/100 mL of water) just after insecticide exposure and on the three following days. Our results revealed that B. anurum (LC50 = 90.9 µg a. i./L) was approximately 32-fold less susceptible to deltamethrin than A. aegypti larvae (LC50 = 2.8 µg a. i./L). However, the number of larvae eaten by B. anurum sublethally exposed to deltamethrin (at 13 µg a. i./L for 24 h) was significantly (P < 0.05) smaller than that recorded for unexposed predators. Furthermore, the deltamethrin-mediated behavioral changes were higher at the highest availability of prey and, as expected, just after insecticide exposure. Thus, sublethal exposure to deltamethrin reduces the ability of B. anurum to capture and prey upon A. aegypti larvae, compromising the efficacy of these insects as naturally occurring mosquito control agents.


Assuntos
Heterópteros/efeitos dos fármacos , Inseticidas/efeitos adversos , Nitrilas/farmacologia , Piretrinas/farmacologia , Aedes , Animais , Comportamento Alimentar/efeitos dos fármacos , Larva , Controle de Mosquitos
10.
Ecotoxicol Environ Saf ; 147: 245-250, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28846929

RESUMO

The increase of agricultural areas with glyphosate-resistant (GR) crops, and use of this herbicide in Brazil, makes necessary to assess its impacts on non-target organisms. The objective was to evaluate the development, reproduction and life table parameters of Podisus nigrispinus (Heteroptera: Pentatomidae) reared on GR-soybean plants treated with glyphosate formulations (Zapp-Qi, Roundup-Transorb-R and Roundup-Original) at the recommended field dose (720g acid equivalent ha-1). Glyphosate formulations had no affect on nymph and adult weight of this predator. Fourth instar stage was shortest with Zapp Qi. Egg-adult period was similar between treatments (26 days) with a survival over 90%. Zapp-Qi and Roundup-Transorb-R (potassium-salt: K-salt) reduced the egg, posture and nymph number per female, and the longevity and oviposition periods of this predator. Podisus nigrispinus net reproductive rate was highest in GR-soybean plants treated with Roundup-Original (isopropylamine-salt: IPA-salt). However, the duration of one generation, intrinsic and finite increase rates, and time to duplicate the population, were similar between treatments. Glyphosate toxicity on P. nigrispinus depends of the glyphosate salt type. IPA-salt was least harmless to this predator. Formulations based on K-salt altered its reproductive parameters, however, the development and population dynamic were not affect. Therefore, these glyphosate formulations are compatible with the predator P. nigrispinus with GR-soybean crop.


Assuntos
Glicina/análogos & derivados , Herbicidas/toxicidade , Heterópteros/efeitos dos fármacos , Animais , Brasil , Monitoramento Ambiental , Feminino , Glicina/toxicidade , Heterópteros/crescimento & desenvolvimento , Ninfa/efeitos dos fármacos , Ninfa/crescimento & desenvolvimento , Reprodução/efeitos dos fármacos , Glifosato
11.
Environ Entomol ; 46(6): 1397-1405, 2017 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-29069307

RESUMO

Thiamethoxam is a neonicotinoid insecticide commonly applied directly to the seeds (seed-treatment) of commercial snap beans, Phaseolus vulgaris L. While previous studies have examined target and nontarget effects of thiamethoxam seed-treatments in snap beans and other crops, to our knowledge, none have been conducted in agroecosystems predominated by the pest Mexican bean beetle, Epilachna varivestis Mulsant (Coleoptera: Coccinellidae). This study examined the effects of thiamethoxam-treated snap beans on E. varivestis, other arthropods, and crop performance in southwestern Virginia. Greenhouse experiments were conducted to evaluate residual toxicity of treated snap beans to E. varivestis and a key predator, Podisus maculiventris (Say) (Hemiptera: Pentatomidae). Treated plants were highly toxic to E. varivestis at 13 d, moderately toxic from 16 to 20 d, and minimally toxic at 24 d. P. maculiventris was unaffected by exposure to treated plants or by feeding on E. varivestis that consumed treated plants. Small plot field experiments in 2014 and 2015 showed no significant effects of thiamethoxam seed-treatments on E. varivestis densities, other arthropods, crop injury, or yield. In 2016, planting was delayed by persistent rain, resulting in early E. varivestis colonization. In this year, thiamethoxam-treated plants had significantly lower densities and feeding injury from E. varivestis, followed by significantly higher yields. Natural enemies were unaffected by seed-treatments in all field experiments. These experiments demonstrated that thiamethoxam seed-treatments provide control of E. varivestis when beetles infest fields within 2 to 3 wk after planting; but otherwise provide negligible advantages. Negative effects from thiamethoxam seed-treatments on nontarget arthropods appear minimal for snap beans in this region.


Assuntos
Besouros , Heterópteros/efeitos dos fármacos , Controle de Insetos , Inseticidas , Neonicotinoides , Nitrocompostos , Oxazinas , Phaseolus , Sementes , Tiazóis , Animais , Besouros/crescimento & desenvolvimento , Heterópteros/crescimento & desenvolvimento , Inseticidas/toxicidade , Larva/crescimento & desenvolvimento , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Ninfa/efeitos dos fármacos , Ninfa/crescimento & desenvolvimento , Oxazinas/toxicidade , Phaseolus/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Tiametoxam , Tiazóis/toxicidade , Virginia
12.
Ecotoxicology ; 26(8): 1147-1155, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28780653

RESUMO

The backswimmer Buenoa tarsalis (Hemiptera: Notonectidae) is a naturally occurring predator of immature stages of mosquitoes. These aquatic predators can suffer from non-targeted exposure to insecticides that are commonly used in aquatic environments to control mosquitoes. Here, we evaluated whether insecticide formulations containing the bacterium Bacillus thuringiensis var. israelensis (Bti) or the organophosphate pirimiphos-methyl would affect the survival and the predatory abilities of B. tarsalis. First, we conducted survival bioassays to estimate the median survival time (LT50) of B. tarsalis when exposed to Bti-based insecticide (at 0.25 and 25 mg a.i./L) and pirimiphos-methyl (at 1, 10 and 1000 mg a.i./L). The highest concentrations of the insecticides were equivalent to the label-recommended field rates. Second, the predatory abilities of B. tarsalis exposed to insecticides were evaluated at three prey densities (3, 6 and 9 mosquito larvae/100 mL water) just after insecticide exposure or after a 24 h recovery time. While the survival of B. tarsalis was significantly reduced with pirimiphos-methyl concentrations ≥10 mg a.i./L, the Bti-exposed predators exhibited similar survival as unexposed predators. Interestingly, after a recovery time of 24 h, B. tarsalis sublethally exposed to pirimiphos-methyl or Bti-based insecticide consistently killed more A. aegypti larvae (at the intermediate density) than unexposed predators. However, for the without-recovery bioassays, the pirimiphos-methyl-exposed predators exhibited reduced predatory abilities at the lowest prey density. Because they do not reduce the survival or the predatory abilities of B. tarsalis, Bti-based insecticides can be considered a safe insecticide to use in the presence of backswimmers.


Assuntos
Proteínas de Bactérias/toxicidade , Endotoxinas/toxicidade , Proteínas Hemolisinas/toxicidade , Heterópteros/efeitos dos fármacos , Inseticidas/toxicidade , Comportamento Predatório/efeitos dos fármacos , Animais , Toxinas de Bacillus thuringiensis , Heterópteros/fisiologia
13.
Environ Toxicol Chem ; 36(5): 1235-1242, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27704607

RESUMO

Backswimmers (Hemiptera: Heteroptera: Notonectidae) are insect predators in a wide variety of freshwater habitats. These insects are well known through their role as mosquito biocontrol agents, their ability to prey on immature fishes and frogs, and because they are often the first to colonize aquatic habitats. As a consequence, these predators may face intended or unintended insecticide exposures that may lead to death or to impairment of essential behaviors (e.g., swimming and position in the water column). The toxicity of deltamethrin (a type II pyrethroid insecticide stressor) and the swimming activity of the backswimmers Buenoa tarsalis and Martarega bentoi were evaluated. Concentration-mortality and survival bioassays were conducted with the insecticide, which were compared with controls without deltamethrin. Deltamethrin was 26-fold more toxic to B. tarsalis (median lethal concentration [LC50] = 4.0 ng a.i./L) than to M. bentoi (LC50 = 102.5 ng a.i./L). The pattern of occupation of B. tarsalis, but not of M. bentoi, in the water column was also disrupted, and B. tarsalis was forced to stay near the water surface longer with exposure to deltamethrin. Thus, based on the findings, B. tarsalis was less resilient to deltamethrin exposure compared with M. bentoi, and the efficacy of swimming-dependent processes might be negatively affected (e.g., prey catching, partner encounter, and antipredator behaviors) for B. tarsalis under deltamethrin exposure. Environ Toxicol Chem 2017;36:1235-1242. © 2016 SETAC.


Assuntos
Heterópteros/efeitos dos fármacos , Inseticidas/toxicidade , Locomoção/efeitos dos fármacos , Nitrilas/toxicidade , Piretrinas/toxicidade , Animais , Feminino , Heterópteros/fisiologia , Dose Letal Mediana , Modelos Lineares , Masculino , Natação
14.
Sci Rep ; 6: 30261, 2016 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-27596436

RESUMO

This research investigated the effects of neem oil on mortality, survival and malformations of the non-target stink bug predator, Podisus nigrispinus. Neurotoxic and growth inhibitor insecticides were used to compare the lethal and sublethal effects from neem oil on this predator. Six concentrations of neem oil were topically applied onto nymphs and adults of this predator. The mortality rates of third, fourth, and fifth instar nymphs increased with increasing neem oil concentrations, suggesting low toxicity to P. nigrispinus nymphs. Mortality of adults was low, but with sublethal effects of neem products on this predator. The developmental rate of P. nigrispinus decreased with increasing neem oil concentrations. Longevity of fourth instar nymphs varied from 3.74 to 3.05 d, fifth instar from 5.94 to 4.07 d and adult from 16.5 and 15.7 d with 0.5 and 50% neem doses. Podisus nigrispinus presented malformations and increase with neem oil concentrations. The main malformations occur in wings, scutellum and legs of this predator. The neem oil at high and sub lethal doses cause mortality, inhibits growth and survival and results in anomalies on wings and legs of the non-traget predator P. nigrispinus indicating that its use associated with biological control should be carefully evaluated.


Assuntos
Glicerídeos/farmacologia , Heterópteros/efeitos dos fármacos , Longevidade/efeitos dos fármacos , Ninfa/efeitos dos fármacos , Terpenos/farmacologia , Asas de Animais/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Feminino , Membro Anterior/anormalidades , Membro Anterior/efeitos dos fármacos , Heterópteros/crescimento & desenvolvimento , Heterópteros/fisiologia , Membro Posterior/anormalidades , Membro Posterior/efeitos dos fármacos , Inseticidas/farmacologia , Longevidade/fisiologia , Masculino , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Comportamento Predatório/efeitos dos fármacos , Asas de Animais/anormalidades
15.
Phytochemistry ; 131: 84-91, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27659594

RESUMO

To test the hypothesis that the plant stress related elicitor cis-jasmone (cJ) provides protection in soybean pods against the seed-sucking stink bug pest, Euschistus heros, the growth of E. heros on cJ-treated pods was investigated using three soybean cultivars differing in insect susceptibility, i.e. BRS 134 (susceptible), IAC 100 (resistant) and Dowling (resistant). E. heros showed reduced weight gain when fed cJ-treated Dowling, whereas no effect on weight gain was observed when fed other treated cultivars. Using analysis of variance, a three factor (cultivar x treatment x time) interaction was observed with concentrations of the flavonoid glycosides daidzin and genistin, and their corresponding aglycones, daidzein and genistein. There were increases in genistein and genistin concentrations in cJ-treated Dowling at 144 and 120 h post treatment, respectively. Higher concentrations of malonyldaidzin and malonylgenistin in Dowling, compared to BRS 134 and IAC 100, were observed independently of time, the highest concentrations being observed in cJ-treated seeds. Levels of glycitin and malonylglycitin were higher in BRS 134 and IAC 100 compared to Dowling. Canonical variate analysis indicated daidzein (in the first two canonical variates) and genistein (in the first only) as important discriminatory variables. These results suggest that cJ treatment leads to an increase in the levels of potentially defensive isoflavonoids in immature soybean seeds, but the negative effect upon E. heros performance is cultivar-dependent.


Assuntos
Ciclopentanos/farmacologia , Glycine max/química , Heterópteros/efeitos dos fármacos , Oxilipinas/farmacologia , Animais , Comportamento Alimentar/efeitos dos fármacos , Flavonoides/análise , Genisteína/análise , Glucosídeos/análise , Isoflavonas/análise , Sementes/química , Glycine max/parasitologia
16.
PLoS One ; 11(6): e0156616, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27284906

RESUMO

Environmental stress in newly-emerged adult insects can have dramatic consequences on their life traits (e.g., dispersion, survival and reproduction) as adults. For instance, insects sublethally exposed to environmental stressors (e.g., insecticides) can gain fitness benefits as a result of hormesis (i.e., benefits of low doses of compounds that would be toxic at higher doses). Here, we experimentally tested whether sublethal exposure to the insecticide imidacloprid would hormetically affect the sexual fitness of newly-emerged adults of the Neotropical brown stink bug Euschistus heros (Hemiptera: Heteroptera: Pentatomidae), which is the most abundant and prevalent insect pest in Neotropical soybean fields. We evaluated the sexual fitness of four couple combinations: unexposed couples, exposed females, exposed males, and exposed couples. Sublethal exposure to dry residues (i.e., contact) of imidacloprid (at 1% of recommended field rate) did not affect insect survival, but led to higher mating frequencies when at least one member of the couple was exposed. However, the average mating duration was shortened when only females were exposed to imidacloprid. Moreover, exposed males showed higher locomotory (walking) activity, lower respiration rates and induced higher fecundity rates when mated to unexposed females. Although the reproductive tracts of exposed males did not differ morphometrically from unexposed males, their accessory glands exhibited positive reactions for acidic and basic contents. Our findings suggest that males of the Neotropical brown stink bug hormetically increase their sexual fitness when cued by impending insecticidal stress in early adulthood.


Assuntos
Heterópteros/efeitos dos fármacos , Hormese/efeitos dos fármacos , Imidazóis/farmacologia , Inseticidas/farmacologia , Nitrocompostos/farmacologia , Reprodução/efeitos dos fármacos , Estresse Fisiológico , Animais , Relação Dose-Resposta a Droga , Meio Ambiente , Feminino , Heterópteros/fisiologia , Masculino , Neonicotinoides , Comportamento Sexual/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Clima Tropical
17.
Chemosphere ; 156: 45-55, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27160634

RESUMO

Lethal and sublethal effects of insecticides on target and non-target arthropods are a concern of pest management programs. Cycloneda sanguinea, Orius insidiosus and Chauliognathus flavipes are important biological control agents for aphids, whitefly, lepidopterus eggs, thrips and mites. All three test species were subjected to a toxicity study using the insecticides acephate, bifenthrin, chlorantraniliprole, chlorpyrifos, deltamethrin, imidacloprid, and thiamethoxam. Experiments were done in the lab and field. In the laboratory we evaluated the mortality and sublethal effects of the concentration that killed 20% of the population (LC20) on feeding, repellence and reproduction of the species tested. The lethal effects of these insecticides at the recommended doses was evaluated in the field. Concentration-response bioassays indicated chlorantraniliprole had the lowest toxicity, while chlorpyrifos and acephate were the most toxic. Test species exposed to filter paper surfaces treated with pyrethroids, neonicotinoids and organophosphates were repelled. On the other hand, test species were not repelled from surfaces treated with chlorantraniliprole. Chlorantraniliprole therefore seemed to be the least dangerous insecticide for these three beneficial arthropod test species.


Assuntos
Besouros/efeitos dos fármacos , Heterópteros/efeitos dos fármacos , Inseticidas/toxicidade , Animais , Agentes de Controle Biológico , Clorpirifos/toxicidade , Besouros/fisiologia , Comportamento Alimentar/efeitos dos fármacos , Feminino , Heterópteros/fisiologia , Imidazóis/toxicidade , Masculino , Neonicotinoides , Nitrilas/toxicidade , Nitrocompostos/toxicidade , Compostos Organotiofosforados/toxicidade , Oxazinas/toxicidade , Fosforamidas/toxicidade , Piretrinas/toxicidade , Reprodução/efeitos dos fármacos , Tiametoxam , Tiazóis/toxicidade , ortoaminobenzoatos/toxicidade
18.
Ciênc. Saúde Colet. (Impr.) ; Ciênc. Saúde Colet. (Impr.);20(1): 125-136, jan. 2015.
Artigo em Português | LILACS | ID: lil-733138

RESUMO

O conceito de recovery tem sido descrito em artigos como um estado de recuperação ou restabelecimento de funções psíquicas, físicas e sociais no funcionamento cotidiano. O objetivo do artigo é analisar concepções terminológicas em diferentes metodologias investigativas e a evolução paradigmática da noção de recovery. Pesquisa bibliográfica sistemática na base Pubmed com as palavras "recovery + schizophrenia", limitada a dois anos retrospectivos e a artigos completos gratuitos. Dezenove artigos foram analisados. A maioria destes busca associações entre dada característica e recovery, poucos são aqueles que discutem a sua concepção de forma que se distinga de termos comuns como "cura" e "reabilitação". Recovery como um estado em que o portador de transtorno mental grave possa sentir-se criador de seus caminhos tende a estar presente em estudos com metodologia qualitativa e em revisões bibliográficas, em que a medida de recovery deixa de relacionar-se à ausência de sintomas e passa a priorizar o quão participativa pode ser a vida de um indivíduo apesar da doença. Alguns estudos quantitativos vislumbram essa diferença conceitual. Em pesquisas qualitativas ocorre expansão na concepção de recovery e nas formas de promovê-lo.


The concept of recovery has been described in papers as a state of psychic, physical and social recuperation of day-to-day functions. The scope of this article is to analyze the concepts of the term in different research methodologies and the paradigmatic evolution of the recovery concept. Systematic bibliographical research was conducted in the Pubmed database using the words "recovery + schizophrenia" limited to freely available full papers published in the previous two years. Nineteen papers were analyzed. The majority of the papers sought associations between characteristic data and recovery; few papers discussed the concept in a way to distinguish it from other words like cure or rehabilitation. Recovery as a state in which people with severe mental illness can feel like the creators of their own itinerary tend to be found in qualitative studies and in bibliographic reviews in which the meaning of recovery is not related to the lack of symptoms and tends to prioritize how participative the life of an individual can be despite the disease. Some quantitative studies detect this conceptual difference. In qualitative research there is an increase in the concept of recovery and in ways of promoting it.


Assuntos
Animais , Arsenicais/farmacologia , Heterópteros/efeitos dos fármacos , Leucina/análogos & derivados , Testes de Toxicidade/métodos , Heterópteros/crescimento & desenvolvimento , Heterópteros/fisiologia , Leucina/toxicidade , Plantas Geneticamente Modificadas , Pólen/química , Fatores de Tempo
19.
J Nanobiotechnology ; 12: 22, 2014 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-24886215

RESUMO

BACKGROUND: Plants have been recognized as a good source of insecticidal agents, since they are able to produce their own defensives to insect attack. Moreover, there is a growing concern worldwide to develop pesticides with low impact to environment and non-target organisms. Hexane-soluble fraction from ethanolic crude extract from fruits of Manilkara subsericea and its triterpenes were considered active against a cotton pest (Dysdercus peruvianus). Several natural products with insecticidal activity have poor water solubility, including triterpenes, and nanotechnology has emerged as a good alternative to solve this main problem. On this context, the aim of the present study was to develop an insecticidal nanoemulsion containing apolar fraction from fruits of Manilkara subsericea. RESULTS: It was obtained a formulation constituted by 5% of oil (octyldodecyl myristate), 5% of surfactants (sorbitan monooleate/polysorbate 80), 5% of apolar fraction from M. subsericea and 85% of water. Analysis of mean droplet diameter (155.2 ± 3.8 nm) confirmed this formulation as a nanoemulsion. It was able to induce mortality in D. peruvianus. It was observed no effect against acetylcholinesterase or mortality in mice induced by the formulation, suggesting the safety of this nanoemulsion for non-target organisms. CONCLUSIONS: The present study suggests that the obtained O/A nanoemulsion may be useful to enhance water solubility of poor water soluble natural products with insecticidal activity, including the hexane-soluble fraction from ethanolic crude extract from fruits of Manilkara subsericea.


Assuntos
Emulsões/química , Heterópteros/efeitos dos fármacos , Inseticidas/química , Manilkara/química , Extratos Vegetais/química , Acetilcolinesterase/metabolismo , Animais , Emulsões/toxicidade , Feminino , Heterópteros/fisiologia , Inseticidas/toxicidade , Masculino , Camundongos , Extratos Vegetais/toxicidade , Solubilidade
20.
Bull Entomol Res ; 104(3): 347-56, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24622042

RESUMO

The rice stem bug, Tibraca limbativentris Stal. (Hemiptera: Pentatomidae) is one of the most important pests of rice crops, especially irrigated crops. Plant defence strategies against these bugs may involve the emission of chemical compounds, which are released following herbivore attacks, directly or indirectly harming pest performance. The aim of this study was to evaluate the influence of constitutive and herbivory-induced volatiles from rice plants (Oryza sativa L.) on the behavioural responses of T. limbativentris adults and egg parasitoids Trissolcus basalis (Wollaston) and Telenomus podisi (Ashmead) (Hymenoptera, Platygastridae). Plant volatiles were collected from undamaged plants of the rice cultivar IRGA 424 and from plants that suffered herbivory by five males or five females of T. limbativentris. Air-entrainment extracts were analysed by GC-flame ionization detector and GC-MS, and insect responses evaluated in a 'Y' olfactometer. T. limbativentris feeding damaged on rice plants induced the release of 16 volatiles compounds in a higher amounts compared to undamaged plants The main compounds induced were (E)-2-hexenal, (E)-2-octen-1-ol, methyl salicylate and α-muurolene. Female bugs were significantly attracted to air-entrainment extracts containing volatiles from undamaged plants compared with air-entrainment extracts containing volatiles emitted from plants damaged by T. limbativentris, whereas males showed no preference. Telenomus podisi females were significantly attracted to volatiles from air-entrainment extracts of plants damaged by females, whereas T. basalis showed no preference. These results suggest that rice plants may be emitting defence compounds, which could be avoided by T. limbativentris females and also acted indirectly by attracting natural enemies.


Assuntos
Heterópteros/fisiologia , Heterópteros/parasitologia , Himenópteros/fisiologia , Oryza/metabolismo , Compostos Orgânicos Voláteis/farmacologia , Animais , Comportamento Apetitivo/efeitos dos fármacos , Brasil , Quimiotaxia/efeitos dos fármacos , Feminino , Cadeia Alimentar , Herbivoria/efeitos dos fármacos , Heterópteros/efeitos dos fármacos , Himenópteros/efeitos dos fármacos , Masculino , Oryza/crescimento & desenvolvimento , Compostos Orgânicos Voláteis/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA