Efficacy of Seven Commercial Household Aerosol Insecticides and Formulation-Dependent Toxicity Against Asian Tiger Mosquito (Diptera: Culicidae)

2020 ◽  
Vol 57 (5) ◽  
pp. 1560-1566
Author(s):  
Junho Yoon ◽  
Huijun An ◽  
Namjin Kim ◽  
Jun-Hyung Tak
Keyword(s):  
Insecticidal Activity ◽  
Mosquito Control ◽  
Test Chamber ◽  
Residual Activity ◽  
Solvent System ◽  
Nozzle Orifice ◽  
Asian Tiger ◽  
Solvent Type ◽  
Water Based ◽  
Orifice Size

Abstract For the indoor and outdoor pest controls, various types of insecticide formulations are available including aerosols, sprays, electric vaporizers, mosquito coils, and traps. In the present study, the insecticidal activity of aerosols, the most commonly used formulation of household insecticides for mosquito control, against Aedes albopictus (Skuse) was assessed using seven commercial products and some attributes which can affect the efficacy of aerosol were investigated as well. The products had difference in their chemical composition of active ingredients, propellant/liquid phase ratios, solvent types, and nozzle orifice sizes, and these characteristics seem to affect the overall insecticidal activity. In general, solvent type dominantly determined the insecticidal activity, where four products in oil-based solvent system showed greater mortality (97.5% in average) than water-based aerosols (38.3% in average) against the mosquitoes located at the far side of the test chamber. The contribution of solvent type and nozzle orifice size were further examined with the sample aerosols, and the orifice size were determined more influential to the spray distance. Regardless of solvent types, the sample products attached to a bigger actuator (0.96 mm in diameter) showed greater knock-down activity (>98%) than the smaller ones (0.48 mm, 62.5% in average) to the back panel in the chamber. On the other hand, solvent system significantly affected the residual activity, as the oil-based and water-based aerosols showed 2.3- and 4.8-fold decrease in KT50 values, respectively, between 1 and 10 min after the spray.

scholarly journals Semifield Evaluation of Improved Passive Outdoor Host Seeking Device (POHD) for Outdoor Control of Anopheles arabiensis Mosquitoes

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Stella T. Kessy ◽  
Bruno A. Nyundo ◽  
Ladslaus L. Mnyone ◽  
Issa N. Lyimo
Keyword(s):  
Carbon Dioxide ◽  
Anopheles Arabiensis ◽  
Mosquito Control ◽  
Real Life ◽  
Residual Activity ◽  
Optimal Placement ◽  
Treatment Combination ◽  
Host Seeking ◽  
Outdoor Biting ◽  
Control Devices

Despite the considerable progress made so far, the effectiveness and mass application of odour-baited outdoor mosquito control devices in pipelines is limited by several factors. These include the design and size of the devices, optimal placement of attractive blends, and nature of materials into which the blends are impregnated. The primary aim of this study was to manipulate these factors to improve the attractiveness of our recently developed passive outdoor host seeking device (POHD) to outdoor biting Anopheles arabiensis. Specifically, the study aimed to determine optimal placement of odour blends and killing bioactives in POHD for maximum attraction and killing of An. arabiensis and to assess the effects of blend types, formulation, and residual activity on attractiveness of the POHD to An. arabiensis. The POHDs baited with attractive blends, carbon dioxide (CO2), and bendiocarb-treated electrostatic netting were placed either towards the top or bottom openings, and other modifications were exposed to An. arabiensis under the semifield system at Ifakara Health Institute (IHI). Each night, a total of 100 starved female, 3–7-day-old, semifield reared An. arabiensis mosquitoes were released, collected the next morning (alive or dead), counted, and recorded. Live mosquitoes were maintained in the semifield insectary and monitored for 24 hours mortality. Each treatment combination of the POHD was tested in three replicates. Overall, the results indicated that the proportion of mosquitoes attracted to and killed in the POHD varied with position of attractants and killing agent (bendiocarb). The POHD with bottom placed attractants and bendiocarb attracted and killed higher proportion of mosquitoes compared to the POHD with top placed attractants and bendiocarb. The highest mortalities were observed when the POHD was baited with a combination of attractive blends and CO2. Moreover, the residual activity of attractive blends applied inside POHD varied with type and formulation of attractive blend. The POHD packed with Mbita and Ifakara blend in microencapsulated pellets (granules) attracted higher proportion of mosquitoes than that baited with soaked nylon-strip formulation of either blends. Interestingly, POHD baited with Mbita blend in microencapsulated pellets (granules) formulation attracted and killed higher proportion of mosquitoes (>90%) than that baited with Ifakara blend even 9 months after application. Conclusively, the POHD remained effective for a relatively longer period of time when baited with bottom placed synthetic blends and CO2 combination, thus warranting further trials under real life situations.

Fabrication of 1D Nanometer Tungsten Trioxide under Different Solvent System

2019 ◽  
Vol 944 ◽  
pp. 1144-1151
Author(s):  
Lin Yan Zhao ◽  
Yue Gang Shen ◽  
You Shu Fan ◽  
Li Wen Ma ◽  
Xiao Li Xi
Keyword(s):  
Tungsten Trioxide ◽  
Dye Sensitized Solar Cells ◽  
Chemical Properties ◽  
Lithium Ion ◽  
Solvent System ◽  
Raw Material ◽  
Solvent Type ◽  
Photocatalytic Activities ◽  
Size And Morphology ◽  
Physical And Chemical

As a cheap and stable transition metal oxide, tungsten trioxide (WO3) has received extensive attentions due to superior physical and chemical properties that could be used in electronic devices, lithium-ion batteries, gas sensors, dye sensitized solar cells, catalysts. In this study, the well-designed 1D architecture of nanowires and nanorods was successfully synthesized via a simple and facile solvethermal method with no template or additives. It is found that both solvent type and concentration of W raw material can affect the size and morphology of WO3significantly in a regular way. Different products showed distinct photocatalytic activities during the processing of degradation methylene blue under visible light, and the underlying reasons for the different photocatalytic activities were discussed.

Acid Adaptation Does Not Promote Survival or Growth of Listeria monocytogenes on Fresh Beef following Acid and Nonacid Decontamination Treatments

2003 ◽  
Vol 66 (6) ◽  
pp. 985-992 ◽  
Author(s):  
J. S. IKEDA ◽  
J. SAMELIS ◽  
P. A. KENDALL ◽  
G. C. SMITH ◽  
J. N. SOFOS
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Residual Activity ◽  
Hot Water ◽  
Acid Solutions ◽  
Acid Adaptation ◽  
Lean Beef ◽  
Water Based ◽  
Survival And Growth

The objective of this study was to evaluate the survival and growth of acid-adapted and nonadapted Listeria monocytogenes inoculated onto fresh beef subsequently treated with acid or nonacid solutions. Beef slices (2.5 by 5 by 1 cm) from top rounds were inoculated with acid-adapted or nonadapted L. monocytogenes (4.6 to 5.0 log CFU/cm2) and either left untreated (control) or dipped for 30 s in water at 55°C, water at 75°C, 2% lactic acid at 55°C, or 2% acetic acid at 55°C. The beef slices were vacuum packaged and stored at 4 or 10°C and were analyzed after 0, 7, 14, 21, and 28 days of storage. Dipping in 75°C water, lactic acid, and acetic acid resulted in immediate pathogen reductions of 1.4 to 2.0, 1.8 to 2.6, and 1.4 to 2.4 log CFU/cm2, respectively. After storage at 10°C for 28 days, populations of L. monocytogenes on meat treated with 55°C water increased by ca. 1.6 to 1.8 log CFU/cm2. The pathogen remained at low population levels (1.6 to 2.8 log CFU/cm2) on acid-treated meat, whereas populations on meat treated with 75°C water increased rapidly, reaching levels of 3.6 to 4.6 log CFU/cm2 by day 14. During storage at 4°C, there was no growth of the pathogen for at least 21 days in samples treated with 55 and 75°C water, and periods of no growth were longer for acid-treated samples. There were no differences between acid-adapted and nonadapted organisms across treatments with respect to survival or growth. In conclusion, the dipping of meat inoculated with L. monocytogenes into acid solutions reduced and then inhibited the growth of the pathogen during storage at 4 and 10°C, while dipping in hot water allowed growth despite initial reductions in pathogen contamination. The results of this study indicate a residual activity of acid-based decontamination treatments compared with water-based treatments for refrigerated (4°C) or temperature-abused (10°C) lean beef tissue in vacuum packages, and these results also indicate that this activity may not be counteracted by prior acid adaptation of L. monocytogenes.

scholarly journals Potential application of chitosan-based nanoparticles containing essential oils against mosquitoes, moths and beetles

2021 ◽  
Vol 9 (3) ◽  
pp. 295-308
Author(s):  
Ana Maria da Silva Maia
Keyword(s):  
Essential Oils ◽  
Larvicidal Activity ◽  
Insecticidal Activity ◽  
Polymeric Nanoparticles ◽  
Chitosan Nanoparticles ◽  
Residual Activity ◽  
Toxicity Tests ◽  
Native Form ◽  
Human Poisoning

The association between the use of synthetic insecticides and the appearance of resistant insects, human poisoning and the environment contamination generated the need to develop new forms to pest control, and essential oils stand out as an alternative. However, due to their volatility and instability, their use in native form is unfeasible. It is possible to circumvent these problems by their encapsulation, and the use of polymeric nanoparticles for this purpose has many advantages, since these systems prevent the oil degradation, and control its release. The first in vivo trials of chitosan nanoparticles containing essential oils with insecticidal activity were published in the late 2010s. Considering the growing interest in this subject, as can be seen from the increase in the number of publications, this review aimed to gather all the papers that presented biological assays using essential oils encapsulated in chitosan nanoparticles against insects. Further, the techniques used to prepare these nanoparticles are also discussed. It was possible to note that the technique called complex coacervation led to smaller particles and most articles describing in vivo tests of chitosan nanoparticles containing essential oils assess their larvicidal activity. Among the tested nanoparticles, the one that had the best larvicidal activity in acute toxicity tests were those obtained by complexing of chitosan with cashew gum and those with the best residual activity were the cross-linked with glutaraldehyde. Chitosan nanoparticles containing essential oils also increased their insecticidal activity in toxicity tests against adult beetles.

scholarly journals Host-Environment Interplay Shapes Fungal Diversity in Mosquitoes

mSphere ◽  
2021 ◽  
Author(s):  
Patil Tawidian ◽  
Kerri L. Coon ◽  
Ari Jumpponen ◽  
Lee W. Cohnstaedt ◽  
Kristin Michel
Keyword(s):  
Mosquito Control ◽  
Mosquito Species ◽  
The United States ◽  
Health Concern ◽  
Asian Tiger Mosquito ◽  
Biological Control Agents ◽  
Public Health Concern ◽  
Content Type ◽  
Asian Tiger ◽  
Fungal Entomopathogens

The Asian tiger mosquito, Aedes albopictus , is the dominant mosquito species in the United States and an important vector of arboviruses of major public health concern. One aspect of mosquito control to curb mosquito-borne diseases has been the use of biological control agents such as fungal entomopathogens.

scholarly journals Assessment of mosquito insecticidal activity of bacterial extracts produced by Colombian strains

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Manuela Agudelo-Restrepo ◽  
Martha Lucia Hernández‐Quesada ◽  
Edinson Yonny Sanabria-Duran ◽  
Sandra Inés Uribe-Soto ◽  
Adriana Ortiz-Reyes ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Serratia Marcescens ◽  
Aedes Albopictus ◽  
Insecticidal Activity ◽  
Mosquito Control ◽  
World Health ◽  
Identification System ◽  
Control Disease ◽  
Health Organization ◽  
Emergence Of Resistance

Aedes aegypti and Aedes albopictus are the major vectors for the transmission of more than 30 disease-causing viruses as dengue fever, dengue hemorragic fever, zika, yellow fever and chikungunya. Vector control is one of the important strategies used in order to fight these diseases in tropical and subtropical countries. However, mosquito control is facing a threat because of the emergence of resistance to synthetic insecticides. The aim of this study was to identify larvicidal and adulticidal activity of secondary metabolites in extracts produced by bacteria isolated from different sources in Colombia. A total of 105 extracts produced from the same number of bacteria were evaluated for their activity against fourth instar larvae and adults of A. aegypti and A. albopictus using standard protocols defined for the WHO (World Health Organization) and CDC (Control Disease Centre, USA). Six extracts showed relevant activity (more than 50% of mosquito larvae were killed after 48 hours), two of them showed to be actives against larvae of Aedes aegypti and four against larvae of Aedes albopictus. None of the extracts showed activity against the mosquitoes in adult stage. The bacteria producing active extracts were identified using the biolog ® identification system as Serratia marcescens ss marcescens, Escherichia hermannii, Serratia marcescens ss marcescens, Bacillus marisflavi, Bacillus atropheus/subtilis and Pseudomonas chlororaphis subsp. aurantiaca. In conclusion, bacterial extracts are a good source for the search of new strategies in the control of mosquitoes. Further studies to determine the compound responsible for the insecticidal activity are in progress.

scholarly journals Effect of the Solvent System on the Morphology and Performance of Nylon 6 Nanofibre Membranes

2019 ◽  
Vol 27 (6(138)) ◽  
pp. 97-101
Author(s):  
Meltem Yanilmaz
Keyword(s):  
Formic Acid ◽  
Binary Solution ◽  
Solvent System ◽  
Nylon 6 ◽  
Solution System ◽  
Solvent Type ◽  
Average Fibre ◽  
And Performance

Nylon 6 nanofibre membranes were prepared by electrospinning of nylon 6 solutions with various volume ratios of trifluoroethyl alcohol (TFE) and formic acid (FA). The effect of the solvent type on the morphology of nylon 6 nanofibre membranes was investigated. Results showed that all membranes studied showed uniform, defect-free structures with very thin nanofibre diameters. The addition of formic acid led to a significant decrease in average fibre diameters. The average fibre diameters were 660, 186, 87, 62 and 30 nm for nylon 6 nonofibre prepared using the binary solution system and trifluoroethyl alcohol/formic acid (100:0), (75:25), (50:50), (25:75) & (0:100) respectively. In addition, the nylon 6 nanofibre membranes prepared using formic acid showed the highest strength with the highest porosity and the lowest average fibre diameters.

Experimental and molecular genetic analysis of the impact of pyrethroid and non-pyrethroid insecticide impregnated bednets for mosquito control in an area of pyrethroid resistance

2000 ◽  
Vol 90 (2) ◽  
pp. 125-132 ◽  
Author(s):  
J.H. Kolaczinski ◽  
C. Fanello ◽  
J.-P. Hervé ◽  
D.J. Conway ◽  
P. Carnevale ◽  
...  
Keyword(s):  
Mosquito Control ◽  
Pyrethroid Resistance ◽  
Molecular Genetic ◽  
Residual Activity ◽  
Molecular Genetic Analysis ◽  
Promising Alternative ◽  
Pirimiphos Methyl ◽  
Selection For ◽  
Mammalian Toxicity ◽  
The Impact

AbstractExperimental huts in Côte d’Ivoire were used to evaluate the pyrethroid alpha-cypermethrin, the non-ester pyrethroid etofenprox, the organophosphate pirimiphos-methyl and the carbamate carbosulfan on bednets against pyrethroid-resistant Anopheles gambiae Giles. To test for selection for the resistance gene by the treated nets, A. gambiae collected live or dead from the huts were kept and analysed for the presence of the kdr gene using a new polymerase chain reaction followed by sequence-specific oligonucleotide probing (PCR–SSOP) for kdr-genotyping. Deliberately holed bednets freshly treated with pirimiphos-methyl or carbosulfan caused over 90% kill of A. gambiae s.s. and Culex spp. However, the mortality with alpha-cypermethrin or etofenprox treated nets was similar to that with untreated nets. Bloodfeeding of A. gambiae s.s. on the sleepers under the nets was only significantly reduced by alpha-cypermethrin and carbosulfan. Tests of the residual activity of the bednets after seven months showed that pirimiphos-methyl had lost its efficacy while carbosulfan still performed well. Once again the pyrethroid treated nets gave similar results to the untreated nets. Selection for the kdr-allele by alpha-cypermethrin and etofenprox, but not by carbosulfan, was indicated by PCR–SSOP genotyping of mosquitoes. Thus carbamates such as carbosulfan, or organophosphates of longer persistence than pirimiphos-methyl and of low mammalian toxicity, would seem to be a promising alternative to be used on bednets, particularly in areas of pyrethroid resistance.

PROTECTION OF BACILLUS THURINGIENSIS FROM INACTIVATION BY SUNLIGHT

1983 ◽  
Vol 115 (9) ◽  
pp. 1215-1227 ◽  
Author(s):  
O. N. Morris
Keyword(s):  
Bacillus Thuringiensis ◽  
Solar Radiation ◽  
Insecticidal Activity ◽  
Choristoneura Fumiferana ◽  
Residual Activity ◽  
Solar Irradiation ◽  
Spore Viability ◽  
Coniferous Trees ◽  
Ultraviolet Absorbers ◽  
Spray Formulation

AbstractThe effectiveness of several commercially available sunlight screens in protecting Bacillus thuringiensis Berliner (B.t.) against inactivation by solar irradiation was assessed in the laboratory and field. Spore viability and residual insecticidal activity of B.t. were rapidly reduced by solar radiation in the range of 300 to 400 nm wavelength. The addition of ultraviolet absorbers, Uvinul DS49 and Erio Acid Red, to a Thuricide spray formulation prolonged the insecticidal residual activity on coniferous trees, resulting in greater effectiveness against the spruce budworm, Choristoneura fumiferana (Clem.), compared with a formulation lacking these protectants.

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