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Journal of Economic Entomology Feb 2021The Mediterranean fruit fly Ceratitis capitata (Wiedemann, 1824) (Diptera: Tephritidae) is among the main pests of fruit crops worldwide. Biological control using...
The Mediterranean fruit fly Ceratitis capitata (Wiedemann, 1824) (Diptera: Tephritidae) is among the main pests of fruit crops worldwide. Biological control using entomopathogenic nematodes (EPNs) may be an alternative to suppress populations of this pest. Thus, the aim of this study was to evaluate the pathogenicity and virulence of six EPN isolates (Heterorhabditis bacteriophora HB, H. amazonensis IBCB-n24, Steinernema carpocapsae IBCB-n02, S. rarum PAM-25, S. glaseri IBCB-n47, and S. brazilense IBCB-n06) against C. capitata pupae. The compatibility of EPNs with different chemical insecticides that are registered for management of C. capitata was also assessed. Isolates of H. bacteriophora HB and S. brazilense IBCB-n06 at a concentration of 1,000 infective juveniles (IJ)/ml proved to be most pathogenic to C. capitata (70 and 80% mortality, respectively). In contrast, the isolates H. amazonensis IBCB-n24, Steinernema carpocapsae IBCB-n02, S. rarum PAM-25, S. glaseri IBCB-n47 provided pupal mortality of less than 60%. Bioassays to determine lethal concentrations indicated that concentrations of 600 IJ/ml (H. bacteriophora HB) and 1,000 IJ/ml (S. brazilense IBCB-n06) showed the highest virulence against C. capitata pupae. In contrast, the highest numbers of IJs emerged at concentrations of 1,200 and 200 IJ/ml. In compatibility bioassays, malathion, spinetoram, phosmet, acetamiprid, and novaluron were considered compatible with and harmless (Class 1) to H. bacteriophora HB and S. brazilense IBCB-n06, according to IOBC/WPRS. This information is important for implementing integrated management programs for C. capitata, using biological control with EPNs, whether alone or in combination with chemical insecticides.
Topics: Animals; Ceratitis capitata; Insecticides; Pest Control, Biological; Pupa; Rhabditida; Tephritidae
PubMed: 33399211
DOI: 10.1093/jee/toaa301 -
Microscopy Research and Technique May 2022Palynological features of tribe Astagaleae L. have been observed with scanning electron microscopy (SEM), to assess features that can be used to re-examine the placement...
Palynological features of tribe Astagaleae L. have been observed with scanning electron microscopy (SEM), to assess features that can be used to re-examine the placement and taxonomic position of tribe. The palynomorph attributes of 10 species included in three genera of Astragaleae (Astragalus L., Glycyrrhiza L., and Oxytropis DC.) are investigated. The assignment of genus Oxytropis in tribe Astragaleae was also reevaluated based on pollen characters. Pollen appear to be prolate, prolate-spheroidal, and subprolate. Polar axis size (P) varies from 31.3 μm ±1 to 17.5 μm ±1.4 and equatorial axis size (E) varies from 22.2 μm ±1.8 to 13.1 μm ±0.9. Prominent apertures found consistently dispersed along the surface of pollen. Three kinds of ornamentation pattern were recorded, that is, reticulate or reticulate-perforate and perforate. The studied species display variation in equatorial and polar diameter, aperturation and sculpturing pattern, exine thickness, and pollen shape. On the basis of descriptive pollen features, a dichotomous taxonomic key and UPGMA analysis has been made for effortless and quick identification. The study concluded that disparities of the entire features are typically unrelenting and concerned with the species and shows potential systematic significance. The combination of palynological attributes in association with additional traits has prospective for systematic identification at species and genus level.
Topics: Microscopy, Electron, Scanning; Phosmet; Pollen; Prospective Studies
PubMed: 34921479
DOI: 10.1002/jemt.24023 -
Microscopy Research and Technique Jul 2022Palynological characterization is considered to be one of the significant taxonomic tools for the delimitation and identification of morphologically complicated taxa....
Palynological characterization is considered to be one of the significant taxonomic tools for the delimitation and identification of morphologically complicated taxa. Hence, the pollen morphology of 12 species of spineless Astragalus L. was examined using light and scanning electron microscopy. Studied pollen were small to medium, monad, prolate to per-prolate and tricolporate type in all studied taxa. The exine sculpturing varied from reticulate to microreticulate whereas colpus ornamentation ranged from scabrate to granulate. Furthermore, maximum polar and equatorial diameter was recorded in Astragalus leucocephalus Bunge. (45.00 μm) and A. pyrrhotrichus Boiss. (22.91 μm) while minimum in A. amherstianus Benth. ex Royle (28.75 μm) and A. amherstianus Benth. ex Royle (15.00 μm), respectively. Similarly, the ratio of polar to equatorial diameter was recorded maximum in A. ophiocarpus Boiss. (2.05). The width of colpi was larger in A. hamosus L. (1.29 μm) and smaller in A. ophiocarpus Boiss. (0.62 μm). We have also found the maximum value of mesocolpium in A. retamocarpus Boiss. (2.08 μm) while minimum in A. oxyglottis Steven ex M.Bieb. (1.87 μm). The quantitative pollen attributes helped in the development of pollen keys for the accurate and quick identification of the studied species. Furthermore, ordination and cluster analysis were performed for the differentiation of the investigated taxa at species level. Based on our results, we conclude that pollen features can be used for the delimitation and identification of the studied taxa. RESEARCH HIGHLIGHTS: Pollen micromorphology is a useful tool for classifying complicated taxa. The pollen micromorphology of 12 spineless species of Astragalus L. was studied using LM and SEM. The observed pollen characteristics aided in Astragalus L. serve for the identification and classification of taxa at specific level.
Topics: Electrons; Fabaceae; Microscopy, Electron, Scanning; Phosmet; Pollen
PubMed: 35302261
DOI: 10.1002/jemt.24097 -
Journal of Economic Entomology Aug 2016The Bonagota salubricola (Meyrick) is a major pest in apple orchards in Brazil, and chemical control has been the primary tool for insect management. To support the...
The Bonagota salubricola (Meyrick) is a major pest in apple orchards in Brazil, and chemical control has been the primary tool for insect management. To support the development of an insect resistance management (IRM) program, baseline studies of the susceptibility of a reference (laboratory) B. salubricola population were conducted; seven wild B. salubricola populations were monitored for susceptibility to insecticide; and the toxicity of some new chemicals to third-instar larvae and adults was evaluated by a leaf dip and ingestion bioassay, respectively. Neonates from the susceptible (laboratory) population exposed to insecticide showed an LC50 ranging from 0.34 (spinetoram) to 30.19 (novaluron) µg of a.i. ml(-1) (88.8-fold variation), so the diagnostic concentrations for an IRM program in Brazil based on the LC99 were as follows: 19.0 µg of a.i./ml chlorantraniliprole, 510.0 novaluron, 72.0 phosmet, 4.1 spinetoram, 12.8 spinosad, and 110.0 tebufenozide. Based on the LC99, significant differences were not observed in the susceptibility of the field and laboratory populations to chlorantraniliprole, phosmet, spinetoram, spinosad, and tebufenozide insecticides, but there were significant differences in the survival rates of the two populations to novaluron insecticide (3.3%). All insecticides at the diagnostic concentrations showed high toxicity to third-instar larvae (mortality rates between 73 to 97%). Phosmet, spinetoram, and spinosad insecticides were toxic to B. salubricola adults (mortality >85%), while chlorantraniliprole, novaluron, and tebufenozide insecticides caused mortality below 5%. The evaluated insecticides showed high toxicity to different developmental stages of B. salubricola, so the diagnostic concentrations may be used in IRM programs in Brazil.
Topics: Animals; Brazil; Insecticide Resistance; Insecticides; Larva; Malus; Moths
PubMed: 27341888
DOI: 10.1093/jee/tow143 -
Journal of Economic Entomology Dec 2019Ceratitis capitata (Wiedemann, 1824) is a significant insect pest of fruits produced worldwide and is capable of causing direct and indirect damage to fruit. Chemical...
Ceratitis capitata (Wiedemann, 1824) is a significant insect pest of fruits produced worldwide and is capable of causing direct and indirect damage to fruit. Chemical control is the most frequently used management strategy, mainly involving organophosphate insecticides. However, the frequent use of this chemical group has resulted in unacceptable chemical residues on fruits. In this study, the toxicity of 18 insecticides was evaluated in adults and larvae of C. capitata in a laboratory. The organophosphate insecticides chlorpyrifos (Lorsban 480BR), phosmet (Imidan 500WP), and malathion (Malathion 1000EC); the spinosyns spinetoram (Delegate 250WG) and spinosad (Tracer); and the pyrethroid alpha-cypermethrin (Fastac 100SC) caused high mortality (>80%) in C. capitata adults in topical application bioassays and by ingestion when mixed with Biofruit 5% food lures. However, the insecticides chlorfenapyr (Pirate), spinetoram and chlorpyrifos produced a significant reduction in larval infestation of the fruits (67, 74, and 84% larval mortality, respectively). Insecticides based on spinosyns, alpha-cypermethrin, and cyantraniliprole are alternatives that can replace organophosphates in the management of C. capitata in the field.
Topics: Animals; Ceratitis capitata; Insect Control; Insecticides; Larva; Malathion; Tephritidae
PubMed: 31290548
DOI: 10.1093/jee/toz194 -
Journal of Exposure Science &... Apr 2019Reducing residential pesticide exposure requires identification of exposure pathways. Compared to the agriculture worker 'take-home' and residential use pathways,...
Reducing residential pesticide exposure requires identification of exposure pathways. Compared to the agriculture worker 'take-home' and residential use pathways, evidence of the 'drift' pathway to pesticide exposure has been inconsistent. Questionnaire data from individuals (n = 99) and dust samples (n = 418) from households across three growing seasons in 2011 were from the For Healthy Kids! study. Summed dimethyl organophosphate pesticide (OP) (Azinphos-Methyl, Phosmet, and Malathion) concentrations were quantified from house dust samples. Spatially-weighted orchard densities surrounding households were calculated based on various distances from homes. Regression models tested associations between orchard density, residential pesticide use, agriculture worker residents, and summed dimethyl OP house dust concentrations. Estimated relationships between orchard density and dimethyl OP in house dust were mixed: a 5% increase in orchard density resulted in 0.3 and 0.5% decreases in dimethyl OP house dust concentrations when considering land-cover 750 m or 1250 m away from households, respectively, but null associations with land-cover 60 m or 200 m away. Dimethyl OP house dust concentrations were 400% higher within homes where at least two residents were agriculture workers. Despite inconclusive evidence for the drift pathway due to potential for bias, relationships between number of agriculture workers and dimethyl OP house dust concentration underscores the take-home pathway.
Topics: Adult; Agriculture; Dust; Environmental Exposure; Female; Housing; Humans; Male; Occupational Exposure; Organophosphorus Compounds; Pesticide Residues
PubMed: 30254255
DOI: 10.1038/s41370-018-0074-5 -
Journal of Economic Entomology Jun 2023The use of toxic baits has become one of the main methods of management of fruit flies in Brazil. The application of toxic baits may cause side effects on the native...
The use of toxic baits has become one of the main methods of management of fruit flies in Brazil. The application of toxic baits may cause side effects on the native parasitoid Doryctobracon areolatus (Hymenoptera: Braconidae). Based on the results, formulations made from the food attractants 3% Biofruit, 1.5% Ceratrap, 1.25% Flyral, 3% Isca Samaritá, 3% Isca Samaritá Tradicional, and 7% sugarcane molasses associated with the Malathion 1000 EC and the ready-to-use toxic bait Gelsura (containing the active ingredient alpha-cypermethrin) were classified as harmful (class 4) to D. areolatus (mortality > 85% at 96 HAE). In contrast, for toxic baits formulated with insecticide phosmet, the mortality ranged from 38% to 72%, classified as slightly harmful or moderately harmful. However, when phosmet was added to the 3% Samaritá Tradicional bait, the mortality was only 3.9% (class 1-harmless), similar to the toxicity observed for the Success 0.02 CB ready-to-use bait (0.24 g a.i. spinosad/l) (<5% mortality). Although toxic baits were formulated with spinosyn-based insecticides, all toxic bait formulations were classified as harmless or slightly harmful (<50% mortality) to D. areolatus, with the exception of 1.5% Ceratrap + spinetoram and 7% Sugarcane molasses + spinosad (≈ 60% mortality-moderately harmful). In addition, these formulations did not show sublethal effects in reducing the parasitism and emergence rate of the F1 generation of D. areolatus in A. fraterculus larvae. The results serve as a basis for the correct use of toxic food baits without affecting the biological control.
Topics: Animals; Hymenoptera; Phosmet; Tephritidae; Insecticides; Malathion; Drosophila; Edible Grain
PubMed: 37032527
DOI: 10.1093/jee/toad069 -
Journal of Environmental Science and... 2015The objective of this study was to determine the levels of pesticides in the fish Prochilodus costatus caught in São Francisco River, one of most important rivers in...
The objective of this study was to determine the levels of pesticides in the fish Prochilodus costatus caught in São Francisco River, one of most important rivers in Brazil. Thirty-six fish were captured in three different areas, and samples of the dorsal muscle and pooled viscera were collected for toxicological analysis. We evaluated the presence of 150 different classes of insecticides, fungicides, herbicides and acaricides by multiresidue analysis technique using liquid chromatography-tandem mass spectrometry (LC-MS/MS), with the limit of detection of 5 ppb. In this study, organophosphorus and carbamate pesticides were detected at the highest levels in the caught fish. Among the 41 organophosphorus pesticides surveyed, nine types were detected (chlorpyrifos, diazinon, dichlorvos, disulfoton, ethion, etrimfos, phosalone, phosmet and pyrazophos) in the muscle, viscera pool, or both in 22 (61.1%) fish. Sampled tissues of 20 (55.6%) fish exhibited at least one of the eight evaluated carbamate pesticides and their metabolites: aldicarb, aldicarb sulfoxide, carbaryl, carbofuran, carbosulfan, furathiocarb, methomyl and propoxur. Fungicides (carbendazim, benalaxyl, kresoxim-methyl, trifloxystrobin, pyraclostrobin and its metabolite BF 500 pyraclostrobin), herbicides (pyridate and fluasifop p-butyl), acaricide (propargite) and pyrethroid (flumethrin) were also detected. In conclusion, P. costatus fish caught in the São Francisco River contained residues of 17 different pesticides, in both muscles and the viscera pool, indicating heavy environmental contamination by pesticides in the study area.
Topics: Animals; Brazil; Characiformes; Environmental Monitoring; Muscle, Skeletal; Pesticide Residues; Pesticides; Rivers; Water Pollutants, Chemical
PubMed: 25844860
DOI: 10.1080/03601234.2015.1011946 -
Journal of Agricultural and Food... Oct 2014This study aimed to use gold nanorods and graphene as key materials to fabricate high-performance substrates for the detection of pesticides by surface enhanced Raman...
This study aimed to use gold nanorods and graphene as key materials to fabricate high-performance substrates for the detection of pesticides by surface enhanced Raman spectroscopy (SERS). Three types of pesticides (azinphos-methyl, carbaryl, and phosmet) were selected. Gold nanorods have great potential to be used as a SERS substrate because it is easy to tune the surface plasmon resonance of the nanorods to the laser excitation wavelength of Raman spectroscopy. Graphene is a promising nanoscale material that can be used for supporting metal nanostructures. Three types of novel SERS substrates were fabricated, including graphene-gold film-gold nanorod (G-Au-AuNR) substrate, gold film-gold nanorod (Au-AuNR) substrate, and graphene coupled with gold nanorods (G-AuNR). The results demonstrate that G-Au-AuNR substrates exhibited the strongest Raman signals of the selected pesticides, followed by the Au-AuNR substrates. G-AuNR exhibited the weakest Raman signals, and no characteristic spectral features of the analytes were obtained. A partial least-squares method was used to develop quantitative models for the analysis of spectral data (R = 0.94, 0.87, and 0.86 for azinphos-methyl, carbaryl, and phosmet, respectively). The G-Au-AuNRs substrate was able to detect all three types of pesticides at the parts per million level with limits of detection at around 5, 5, and 9 ppm for azinphos-methyl, carbaryl, and phosmet, respectively. These results indicate that combining gold nanorods and graphene has great potential in the fabrication of sensitive, lightweight, and flexible substrates for SERS applications to improve food safety.
Topics: Food Contamination; Gold; Graphite; Nanotubes; Pesticides; Spectrum Analysis, Raman
PubMed: 25317673
DOI: 10.1021/jf5036417 -
Plants (Basel, Switzerland) Feb 2024The spotted-wing drosophila, (Matsumura) (Diptera: Drosophilidae), is a pest that reduces the productivity of small fruits. Entomopathogenic nematodes (EPNs) and...
The spotted-wing drosophila, (Matsumura) (Diptera: Drosophilidae), is a pest that reduces the productivity of small fruits. Entomopathogenic nematodes (EPNs) and chemical insecticides can suppress this pest, but the compatibility of the two approaches together requires further examination. This laboratory study evaluated the compatibility of IBCBn 06, IBCBn 02, IBCBn 24, and HB with ten chemical insecticides registered for managing pupae. In the first study, most insecticides at the recommended rate did not reduce the viability (% of living infective juveniles (IJs)) of and both species. The viability of was lowered by exposure to spinetoram, malathion, abamectin, azadirachtin, deltamethrin, lambda-cyhalothrin, malathion, and spinetoram after 48 h. During infectivity bioassays, phosmet was compatible with all the EPNs, causing minimal changes in infectivity (% pupal mortality) and efficiency relative to EPN-only controls, whereas lambda-cyhalothrin generally reduced infectivity of EPNs on pupae the most, with a 53, 75, 57, and 13% reduction in infectivity efficiency among , and , respectively. The second study compared pupal mortality caused by the two most compatible nematode species and five insecticides in various combinations. Both species caused 78-79% mortality among pupae when used alone, and were tested in combination with spinetoram, malathion, azadirachtin, phosmet, or novaluron at a one-quarter rate. Notably, caused 79% mortality on pupae when used alone, and 89% mortality when combined with spinetoram, showing an additive effect. Novaluron drastically reduced the number of progeny IJs when combined with by 270 IJs and by 218. Any adult flies that emerged from EPN-insecticide-treated pupae had a shorter lifespan than from untreated pupae. The combined use of and compatible chemical insecticides was promising, except for novaluron.
PubMed: 38475479
DOI: 10.3390/plants13050632