scholarly journals EVALUATION OF PYRETHROID AND BOTANICAL BARRIER INSECTICIDES AGAINST AEDES ALBOPICTUS IN THE LABORATORY AND FIELD

2021 ◽  
Vol 66 (1) ◽  
pp. 47-53
Author(s):  
Steven T. Smoleroff

Outdoor residual insecticide applications are useful for preventing or reducing mosquito populations at focal areas. Until recently, pyrethroids have been the only option for barrier sprays in mosquito control. In this study, three pyrethroid (Onslaught, Cyzmic CS, DeltaGard) and two botanical (Nature-Cide, Essentria IC3 ) outdoor residual insecticides were comparatively tested at low, mid, and high label rates against adult Aedes albopictus in both laboratory bioassays and field trials in St. Augustine, FL, from May-August 2017. Bioassays indicated NatureCide and Cyzmic CS were the most toxic across all three dilution ratios followed by DeltaGard, Onslaught, and Essentria IC3 , respectively. In field trials Nature-Cide and Onslaught were the only products that reduced mosquito abundance at the low rate. However, at the mid rate NatureCide and Onslaught caused ~90% percent reduction of adult female Ae. albopictus in the field, the highest of all tested products. The performance of DeltaGard (79% reduction in field counts), Essentria IC 3 (64%), and Cyzmic CS (36%) in the field were not similar to the laboratory results. The universally high performance of Nature-Cide indicates that mosquito control operations should expand consideration to botanical based insecticides for field operations.

2017 ◽  
Vol 107 (6) ◽  
pp. 724-733 ◽  
Author(s):  
F.D. Rinkevich ◽  
J.W. Margotta ◽  
V. Pokhrel ◽  
T.W. Walker ◽  
R.H. Vaeth ◽  
...  

AbstractAdulticides applied against mosquitoes can reduce vector populations during times of high arbovirus transmission. However, impacts of these insecticides on pollinators and other non-target organisms are of concern to mosquito control professionals, beekeepers and others. We evaluated mortality of Culex quinquefasciatus and Apis mellifera when caged insects were exposed to low and high label rates of four common adulticides (Aqua-Pursuit™ [permethrin], Duet® [prallethrin + sumithrin], Fyfanon® [malathion] and Scourge® [resmethrin]) at six distances up to 91.4 m from a truck-mounted ultra-low-volume sprayer. Honey bee mortality was both absolutely low (<10%) and low relative to mosquito mortality for most products, distances, and application rates. Exceptions were at the high rate of Fyfanon (honey bee mortality of 22–100% at distances ≤61 m) and the low rate of Scourge (mortality <10% for both insects). The greatest ratios of mosquito-to-honey bee mortality were found for the low rate of Fyfanon (30× greater) and the high rate of Duet (50× greater). Aqua-Pursuit and Fyfanon tended to increase mortality of both species at closer distances and at higher application rate; this was related to increased number and size of spray droplets. Wind speed and temperature had inconsistent effects on mortality of mosquitoes only. In this bioassay designed to have insects directly intercept insecticide droplets, mosquito adulticides applied at low rates and at >61 m had limited impacts on honey bee mortality while providing effective mosquito control.


Author(s):  
Bethany L McGregor ◽  
Bryan V Giordano ◽  
Alfred E Runkel ◽  
Herbert N Nigg ◽  
H Lee Nigg ◽  
...  

Abstract Mosquito control districts in the United States are limited to two main classes of adulticides, pyrethroids and organophosphates, to control mosquitoes. Two adulticides used to control domestic mosquitoes are Fyfanon EW (malathion, organophosphate) and DeltaGard (deltamethrin, pyrethroid). While the effect of these pesticides on European honeybees (Apis mellifera L., Hymenoptera: Apidae) has been investigated, effects on native pollinators need additional research. The purpose of this study was to investigate the acute nontarget effects of these pesticides on Bombus impatiens Cresson (Hymenoptera: Apidae), a native North American bumble bee species, and compare these effects to wild and laboratory strains of mosquitoes (Aedes aegypti (L.) and Culex quinquefasciatus Say, Diptera: Culicidae) through field and laboratory assays. Bombus impatiens was found to be resistant to Fyfanon EW (x̅ = 6.7% mortality at 50-µg malathion per bottle) at levels that caused significant mortality to study mosquitoes (86.2 ≥ x̅ ≥ 100% mortality) in laboratory bottle bioassays. Comparatively, B. impatiens demonstrated greater mortality to DeltaGard (93.3%) at 2.5-µg deltamethrin/bottle than any mosquito colony assayed (14.1 ≥ x̅ ≥ 87.0% mortality). Only DeltaGard was tested in field applications. In the field, we observed acute effects of DeltaGard on mosquitoes and B. impatiens at 25- and 75-m distance from a truck-mounted ultra-low volume fogger, although treatment effects were not significant for B. impatiens. Additional wild-caught nontarget mortality to DeltaGard field trials was also evaluated. This study indicated that common mosquito control adulticides do cause nontarget mortality to B. impatiens but that impacts are variable depending on pesticide and further studies are needed.


2019 ◽  
Author(s):  
Maria Vittoria Mancini ◽  
Christie S. Herd ◽  
Thomas H. Ant ◽  
Shivan M. Murdochy ◽  
Steven P. Sinkins

AbstractThe global incidence of arboviral diseases transmitted by Aedes mosquitoes, including dengue, chikungunya, yellow fever, and Zika, has increased dramatically in recent decades. The release of Aedes aegypti carrying the maternally inherited symbiont Wolbachia as an intervention to control arboviruses is being trialled in several countries. However, these efforts are compromised in many endemic regions due to the co-localization of the secondary vector Aedes albopictus, the Asian tiger mosquito. Ae. albopictus has an expanding global distribution following incursions into a number of new territories. To date, only the wMel and wPip strains of Wolbachia have been reported to be transferred into and characterized in this vector. A Wolbachia strain naturally infecting Drosophila simulans, wAu, was selected for transfer into a Malaysian Ae. albopictus line to create a novel triple-strain infection. The newly generated line showed self-compatibility, moderate fitness cost and complete resistance to Zika and dengue infections.Author summaryAedes albopictus, the invasive Asian tiger mosquito, is responsible for numerous outbreaks of important viruses such as dengue and Zika in various regions of the world. The need for alterative control interventions propelled the development of a novel approach that exploits a natural insect symbiont, Wolbachia; when transferred into non-native hosts, these maternally-inherited bacteria are able to interfere with the transmission of mosquito-borne viruses, and also provide reproductive advantages to the host, offering a promising tool for self-sustaining field applications. Currently, several field trials are ongoing for the primary vector of dengue and several other arboviruses, Aedes aegypti, providing encouraging results. In this study, Ae. albopictus has been targeted for a similar approach: this mosquito species naturally carries two strains of Wolbachia. The artificial introduction of a third, non-native strain made this line less able to transmit dengue and Zika viruses and had an impact on its fitness.


2005 ◽  
Vol 130 (2) ◽  
pp. 196-202 ◽  
Author(s):  
Marilyn H.Y. Hovius ◽  
Irwin L. Goldman ◽  
Kirk L. Parkin

Breeders have found field screening for white rot (Sclerotium cepivorum Berk.) resistance in onion (Allium cepa L.) to be unreliable since consistently moderate to high disease levels that significantly differentiate cultivars do not occur over field sites and years. The objective was to determine if differences in onion white rot resistance levels were associated with differing S-alk(en)yl-l-cysteine sulfoxide (ACSO) levels. A collection of onion breeding lines and hybrids were evaluated in field trials at six sites in 1999-2001. High performance liquid chromatography was used to analyze ACSOs in onion plant organs. Four main cysteine-sulfoxides exist in Allium L. species: methyl (MCSO), 2-propenyl (2-PeCSO), 1-propenyl (1-PeCSO), and propyl (PCSO). 1-PeCSO was predominant in onion leaves, bulbs, and roots. 2-PeCSO was found in trace amounts in onion leaves and roots. There was significantly more 2-PeCSO and total ACSO (roots only) and 1-PeCSO (roots and bulbs) in accessions that were more susceptible to white rot in the field trials. This is the first report of significant differences in ACSO contents among white rot susceptible and resistant onions. A covariance analysis was used to determine if the ACSO levels that significantly distinguished among accessions could predict field onion white rot reaction. 1-PeCSO from both roots and bulbs was the best predictor of field disease incidence in field sites that had low, moderate, and high disease levels. Although the ACSO concentrations were not assessed on an individual plant basis, breeders may be able to screen onions for resistance to S. cepivorum by comparing onion root or bulb 1-PeCSO levels based on the results from this research. White rot incidence in the field should be higher in those plants whose roots and bulbs have the highest levels of 1-PeCSO.


Author(s):  
Fraser King ◽  
Jenny Been ◽  
Robert Worthingham ◽  
Grant Rubie

Three-layer FBE-polyolefin coatings offer the promise of good adhesive and corrosion properties from the FBE layer coupled with resistance to mechanical damage from the outer polyolefin layer. TransCanada Pipelines have been investigating the long-term behaviour of High Performance Composite Coating (HPCC) using a combination of laboratory testing and field trials. In the laboratory, panels of HPCC were subjected to standard CD disbondment testing following a two-stage degradation process. The degradation process, designed to simulate field exposure, involved impact damage followed by exposure to either a hot-water soak (60°C), or to microbiologically active soil with and without the application of CP. Following exposure, the duplicate panels were subject to 28-day CD disbondment tests to determine the extent of damage caused by the combination of impact and soil/hot water exposure. In the field, a section of HPCC coating was excavated and examined after 11 years service. In addition to visual inspection, the coating was examined in situ using a newly developed impedance technique EISPlus. This technique is a development of earlier EIS techniques and allows the dielectric properties of the coating to be determined in addition to the impedance of the solution-filled pores. EISPlus provides an improved sensitivity for high-impedance coatings, such as FBE, HPCC, and polyolefin tape. Furthermore, since it is a dry technique, rapid measurements can be made on coatings exposed to field conditions allowing the in-service performance to be determined. Results of both the laboratory testing and field EISPlus measurements are presented and the long-term performance of the coating discussed.


Author(s):  
R. Orndorff ◽  
L. Foster ◽  
R. Sheppert

Recent independent lab testing and field trials have verified significant wear and friction reductions are possible with a new family of polymer alloy bearings. Advanced water-lubricated bearings with projected pressures in the range of 3448 to 6895 kPa (500 to 1,000 psi) are possible with length-to-diameter (L/D) ratios as low as 0.2 without end leakage. Much higher pressures are made possible by dimensionally controlling the “stiffness” (shape factor) of the rubber/plastic alloy bearing.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Umar Khan ◽  
Sonia Biccai ◽  
Conor S. Boland ◽  
Jonathan N. Coleman

AbstractThe development of low-cost ultrafiltration membranes with relatively high flow rate and selectivity is an important goal which could improve access to clean water in the developing world. Here we demonstrate a method to infuse mixtures of graphene nanosheets and Teflon nanoparticles into ultra-cheap glass fibre membranes. Annealing the resultant composites leads to coalescence of the Teflon, resulting in very stable membranes with significantly enhanced mechanical properties. In filtration tests, while adding ~ 10 wt% graphene/Teflon to the glass fibre membrane decreased the flow rate by × 100, the selectivity improved by × 103 compared to the neat glass fibre membrane. This combination of selectively and flow rate was significantly better than any commercial membrane tested under similar circumstances. We found these membranes could remove > 99.99% of 25–250 nm diameter SiC nanoparticles dispersed in ethanol, transmitting only particles with diameters < 40 nm, performance which is superior to commercial alumina membranes. Field trials on dirty canal water showed these composite membranes to remove aluminium to a level × 10 below the EU limit for drinking water and reduce iron and bacteria contents to below detectable levels.


2019 ◽  
Vol 43 (3) ◽  
pp. 1238-1246 ◽  
Author(s):  
Duo Zhang ◽  
Chaoqi Bi ◽  
Qingliu Wu ◽  
Guangya Hou ◽  
Guoqu Zheng ◽  
...  

It is a challenge to commercialize tin dioxide-based anodes for lithium-ion batteries due to their low rate capability and poor cycling performance of the electrodes.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Anne C. Latreille ◽  
Pascal Milesi ◽  
Hélène Magalon ◽  
Patrick Mavingui ◽  
Célestine M. Atyame

Abstract Background In recent years, the Asian tiger mosquito Aedes albopictus has emerged as a species of major medical concern following its global expansion and involvement in many arbovirus outbreaks. On Réunion Island, Ae. albopictus was responsible for a large chikungunya outbreak in 2005–2006 and more recently an epidemic of dengue which began at the end of 2017 and is still ongoing at the time of writing. This dengue epidemic has seen a high number of human cases in south and west coastal regions, while few cases have been reported in the north and east of the island. To better understand the role of mosquito populations in such spatial patterns of dengue virus transmission in Réunion Island, we examined the genetic diversity and population structure of Ae. albopictus sampled across the island. Results Between November 2016 and March 2017, a total of 564 mosquitoes were collected from 19 locations in three main climatic regions (West, East and Center) of Réunion Island and were genotyped using 16 microsatellite loci. A high genetic diversity was observed with 2–15 alleles per locus and the average number of alleles per population varying between 4.70–5.90. Almost all FIS values were significantly positive and correlated to individual relatedness within populations using a hierarchical clustering approach based on principal components analyses (HCPC). However, the largest part of genetic variance was among individuals within populations (97%) while only 3% of genetic variance was observed among populations within regions. Therefore, no distinguishable population structure or isolation by distance was evidenced, suggesting high rates of gene flow at the island scale. Conclusions Our results show high genetic diversity but no genetic structure of Ae. albopictus populations in Réunion Island thus reflecting frequent movements of mosquitoes between populations probably due to human activity. These data should help in the understanding of Ae. albopictus vector capacity and the design of effective mosquito control strategies.


2007 ◽  
Vol 34 (3) ◽  
pp. 239 ◽  
Author(s):  
Stuart McLean ◽  
Susan Brandon ◽  
Roger Kirkwood

Cabergoline is a potent inhibitor of prolactin release and a potential fertility control agent for foxes. To understand how cabergoline could behave in baits deployed for fox control, we conducted laboratory and field trials to investigate the stability of cabergoline when (1) in solution, (2) injected into a bait (deep-fried liver and Foxoff®) and (3) exposed to a range of environmental conditions, including burial. Cabergoline, dissolved in a 1% acetic acid solution, and its carboxylic acid hydrolysis product can be assayed using high-performance liquid chromatography. When stored at 4°C and at room temperature, cabergoline in solution was stable for up to 36 days. When stored under cool (≤15°C), dry conditions, cabergoline (800 µg) in commercial Foxoff® and deep-fried ox-liver baits was stable for 28 and 7 days, respectively; stability was reduced by increases in temperature (tested up to 40°C) and humidity. Recovery of cabergoline from buried baits exposed to a range of field conditions decreased rapidly in the first week, but after 56 days remained detectable at levels of 6–22% of the injected amounts. This study has important implications for baiting campaigns that use cabergoline for fox control.


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