Ground-Based Pyrethroid Adulticides Reduce Mosquitoes But Not Nontarget Insects in Central Florida.

As stewards of public and environmental health, mosquito control agencies are rightfully concerned about impacts on nontarget organisms. This study examined the impact of a modern, pyrethroid based ground adulticide program using ultra-low volume applications in a metropolitan county in central Florida. Nontarget insects and mosquitoes were collected in a before-after control-impact design at 21 sites over 1.5 years. While mosquitoes were reduced, we found no evidence for reduction of nontarget insects, regardless of taxon. Night-flying Lepidoptera may experience greater risk than other nontarget taxa, but overall effects of adulticide missions on this group were low and inconsistent. Instead, meteorology, habitat, and phenology dominate patterns of nontarget abundance. Mosquito reduction was more clearly observed and corrected post-mission reduction was consistent with results expected in complex urban and suburban treatment zones.

Application of ultra-low-volume spray for the control of vegetable disease in greenhouse: Investigation of formulation performance and potential dermal exposure.

BACKGROUND: The use of pesticides in greenhouse vegetable cultivation is necessary and significant. However, traditional pesticide application methods such as the use of backpack sprayers with water-diluted pesticides have certain drawbacks, e.g., uneven distribution, high labor intensity, and safety risks. RESULTS: In this work, fluazinam ultra-low-volume liquids (Flu-ULVs) were prepared using oily solvents as carriers. The effects of different oils on the physical properties of the preparations were investigated. The Flu-ULV can be sprayed directly using a hand-held ultra-low-volume (ULV) sprayer without dilution with water. Compared with commercial water-based suspension concentrates of fluazinam, the Flu-ULV samples showed better wetting of tomato leaves, better atomization, and more uniform droplet distribution. At a dosage of 300 mL/ha, the coverage rate of tomato leaves ranged from 32.47% to 79.3%, with a droplet deposition density of 556 to 2017 droplets/cm2. Application of Flu-ULVs provided 70.86% control efficacy against gray mold in tomatoes, which was higher than those achieved with reference products. Dermal exposure to Flu-ULVs was also evaluated in greenhouse experiments. The coverage rates for all parts of the operator's body ranged from 0.02% to 0.07%, with deposition volumes of 2.23 to 12.26 µg/cm2. CONCLUSION: Ground ULV spraying of fluazinam was proved to be an effective and safe management option for the control of tomato gray mold in greenhouses. This study laid a foundation for the use of ultra-low volume spray to control vegetable diseases in greenhouse, especially those induced by high humidity environment. © 2024 Society of Chemical Industry.

Assessment of Truck-Mounted Area-Wide S-methoprene Applications to Manage West Nile Virus Vector Species in the Suburbs of Chicago, IL, USA.

West Nile virus remains the leading cause of arboviral neuroinvasive disease in the United States, despite extensive efforts to control the mosquito vectors involved in transmission. In this study, we evaluated the effectiveness of Altosid SR-20 (active ingredient, S-methoprene 20%) larvicide applications using truck-mounted ultra-low volume (ULV) dispersal equipment to target Culex pipiens Linnaeus (Diptera: Culicidae) and Cx. restuans (Theobald)larvae. A combination of emergence bioassays, open-field measurements of deposited S-methoprene and spray distribution using gas chromatography-mass spectrometry, and assessments of adult Culex spp. populations in response to applications were conducted over the summer of 2020 within the North Shore Mosquito Abatement District (IL, USA). Open-field applications revealed that dispersed Altosid SR-20 using ULV equipment was effective (75% emergence inhibition in susceptible lab strain Cx. pipiens larvae) up to 53 m. In suburban neighborhood applications, we found that S-methoprene deposition and larval emergence inhibition (EI) in front yards did not differ significantly from backyards. An overall EI of 46% and 28% were observed for laboratory strain Cx. pipiens and wild Cx. restuans larvae respectively, and both had an EI significantly higher than the untreated control group. The EI of exposed wild Cx. pipiens larvae did not differ from the untreated controls, suggesting an increased tolerance to S-methoprene. No difference in abundance of gravid or host-seeking adult Culex spp. post-application was detected between treated and untreated sites. These results document the ability of area-wide application to distribute S-methoprene, but this strategy will need further modifications and evaluation for Culex spp. management.

Reduced Potential for Consecutive Truck-Mounted Ultra-Low Volume Mosquito Adulticide Applications in Chicago Metropolitan Area Due to Weather Conditions.

To increase the effectiveness of adult mosquito control, more frequent ultra-low volume (ULV) applications have been suggested. In the Chicago area, weather may be a limiting factor to more frequent applications. To investigate this, ULV adulticidal application dates from the Northwest Mosquito Abatement District during June 2011 to September 2020 were compared to historical weather data-wind and rain patterns to determine optimum conditions for conducting ULV treatments. During the 85 applications performed during 2011-20, there would have been an opportunity, based on weather conditions, for an additional consecutive night for about half (48.2%) of the time. These opportunities diminished with each additional application. The most intensive response possible would have been a spray of 5 consecutive nights, which occurred once in 3 of the 10 years investigated.

Hybrid Janus Membrane with Dual-Asymmetry Integration of Wettability and Conductivity for Ultra-Low-Volume Sweat Sensing.

Highly sensitive and selective analysis of sweat at ultra-low sample volume remains a major challenge in the field of biosensing. Manipulation of small volumes of liquid for efficient sampling is essential to address this challenge. A hybrid Janus membrane with dual-asymmetry integration of wettability and conductivity is developed for regulated micro-volume liquid transport in wearable sweat biosensing. Unlike the uncontrollable liquid diffusion in a conventional porous membrane, the asymmetric wettability of porous Janus membrane leads to unique unidirectional liquid transport with high breakthrough pressure (1737.66 Pa) and fast self-pumping rate (35.94 µL/min) for micro-volume liquid sampling. The asymmetric conductive layer shows excellent flexible conductivity, anti-interference of friction, and efficient electrochemical interface due to the in situ generation of gold nanoparticles on one side of the membrane. The fabricated Pt-enzyme electrodes on the membrane promises effective testing range, great selectivity, and high sensitivity and accuracy (correlation efficiency, glucose: R2 = 0.999, lactate: R2 = 0.997), enabling ultra-low volume (∼0.15 µL) real time measurements on the skin surface. The innovative Janus membrane with unidirectional, self-pumping, and anti-interference performance provides a new strategy for miniaturized wearable microfluidic sweat electrochemical biosensor preparation in athletic performance evaluation, health monitoring, disease diagnosis, intelligent medicine, and so forth.

Isolation of sensory hair cell specific exosomes in human perilymph.

Evaluation of hearing loss patients using clinical audiometry has been unable to give a definitive cellular or molecular diagnosis, hampering the development of treatments of sensorineural hearing loss. However, biopsy of inner ear tissue without losing residual hearing function for pathologic diagnosis is extremely challenging. In a clinical setting, perilymph can be accessed, potentially allowing the development of fluid based diagnostic tests. Recent approaches to improving inner ear diagnostics have been focusing on the evaluation of the proteomic or miRNA profiles of perilymph. Inspired by recent characterization and classification of many neurodegenerative diseases using exosomes which not only are produced in locally in diseased tissue but are transported beyond the blood brain barrier, we demonstrate the isolation of human inner ear specific exosomes using a novel ultrasensitive immunomagnetic nano pom-poms capture-release approach. Using perilymph samples harvested from surgical procedures, we were able to isolate exosomes from sensorineural hearing loss patients in only 2-5 µL of perilymph. By isolating sensory hair cell derived exosomes through their expression level of myosin VIIa, we for the first-time sample material from hair cells in the living human inner ear. This work sets up the first demonstration of immunomagnetic capture-release nano pom-pom isolated exosomes for liquid biopsy diagnosis of sensorineural hearing loss. With the ability to isolate exosomes derived from different cell types for molecular characterization, this method also can be developed for analyzing exosomal biomarkers from more accessible patient tissue fluids such as plasma.

Bowel-cleansing efficacy of the 1L polyethylene glycol-based bowel preparation NER1006 (PLENVU) in patient subgroups in two phase III trials.

BACKGROUND: Adequate bowel preparation prior to colonoscopy is essential for visualization of the colonic mucosa to maximize adenoma and polyp detection. The risk of inadequate bowel cleansing is heightened if the patient is older, male, overweight, and has comorbidities, such as diabetes. This post hoc analysis of the combined MORA and NOCT clinical trials explores the efficacy of evening/morning split-dose regimens of NER1006 (PLENVU®, Norgine Ltd), a 1-liter polyethylene glycol (PEG) bowel preparation, to evaluate its bowel-cleansing efficacy in patients at risk for inadequate cleansing. METHODS: Patients requiring colonoscopy were randomized to receive evening/morning split-dosing of either NER1006, 2-liter (2L) PEG and ascorbate, or oral sulfate solution (OSS). Bowel-cleansing efficacy was assessed by treatment-blinded central readers using the validated Harefield Cleansing Scale (HCS). RESULTS: Split-dose NER1006 was associated with high levels of cleansing, ranging between 87.0% and 94.0% across all patient subtypes (n = 551), including patients with obesity or diabetes. However, patients aged >65 years and <45 years showed significantly greater rates of successful cleansing than patients aged 45-65 years (94.0% versus 94.2% versus 87.0%, p = 0.002). The high-risk patient subgroup, which included obese males aged ⩾60 years, had significantly improved overall and high-quality bowel-cleansing success rates of 100% (33/33) and 72.7% (27/33) on the HCS with NER1006, compared with 86.7% (26/30) and 50% (15/30) with the comparator solutions (p = 0.015 and p = 0.033, respectively). In this high-risk subgroup, adenoma detection was greater per patient receiving NER1006 versus the comparator group (1.82 versus 0.93, p = 0.041). NER1006 was the only treatment that enabled the detection of patients with ⩾5 adenomas [9.1% (3/33) versus 0/30, p = 0.047]. CONCLUSION: NER1006 effectively cleansed a broad range of patients and offered superior bowel cleansing versus 2LPEG/OSS in patients at increased risk of colorectal cancer. Future research should establish whether more effective cleansing also enables improved adenoma detection. PLAIN LANGUAGE SUMMARY: A low-volume bowel preparation solution to better detect lesions associated with colorectal cancer during colonoscopyColorectal cancer (CRC) is the fourth most commonly diagnosed cancer in the world. Obese men over the age of 65 years are at particularly increased risk of developing CRC. If the changes in their large intestine (colon) could be seen more clearly during a colonoscopy (where a small camera is inserted via the anus to examine the bowels from the inside), patients who need treatment would be diagnosed earlier, thus improving their chances of survival. In this paper we discuss the use of a bowel preparation solution that is more convenient for patients (less to drink) but also cleans bowels more effectively, meaning more lesions are detected than when other solutions are used. This improved cleansing, and thus better visualization, occurred in a range of patients, including those at higher risk of CRC, such as older, overweight men.

Efficient pesticide formulation and regulation mechanism for improving the deposition of droplets on the leaves of rice (Oryza sativa L.).

BACKGROUND: The effective deposition of pesticide droplets on the target leaf surface is critical for improving the utilization of pesticides. We proposed a new way to enhance the droplet deposition on the target leaf surface by changing the properties of pesticide formulation, and this formulation can be sprayed directly or at a low dilution. In addition, it is a simple method to select a suitable concentration and formulation by evaluating the interfacial dilational rheological properties of pesticide droplets. RESULTS: The wetting behavior of two types of pesticide formulations prepared by oil-based solvent on the rice leaf surface was investigated based on the surface free energy, surface tension, contact angle, adhesion tension, and adhesion work. The interfacial dilational rheological properties of different pesticide solutions were measured as a function of concentration. This study clearly demonstrates the fact that water-in-oil emulsion has a better wettability than oil-in-water emulsion, especially with the increase of the concentration of the solution, the droplets can be wetted and spread faster on the leaves. Compared with vegetable oil (methyl oleate), mineral oil (solvent oil No. 200) has smaller dilational modulus and surface tension, showing excellent wetting properties. CONCLUSION: The water-in-oil emulsion prepared with solvent oil No. 200 has the smallest dilational modulus, and the spray droplets spread rapidly to the maximum wetting area on the rice leaves, which can be used in an ultra-low volume spray. The results provide new insights into how to increase the deposition of droplets on superhydrophobic leaf surfaces by screening formulations and concentrations. © 2021 Society of Chemical Industry.

New Ultra Low Volume Bowel Preparation and Overview of Existing Bowel Preparations.

BACKGROUND: Adequate bowel cleansing is essential in achieving a good quality colonoscopy. However, one of the barriers to achieving high-quality bowel cleansing is the patient's tolerability. Different bowel preparations have been developed to improve tolerability while maintaining adequate bowel cleansing. OBJECTIVES: We aim to explore the pros and cons of commonly used bowel preparations, particularly highlighting the new ultra-low volume bowel preparation. METHODS: Extensive literature search was carried out on various databases to evaluate the effectiveness and side effects of different bowel cleansing agents, including findings of recent clinical trials on ultra-low bowel preparation. RESULTS: Polyethylene glycol (PEG) has been commonly used as a bowel prep. Due to its high volume required to ingest to achieve an adequate effect, it has been combined with various adjuncts to reduce the volume to make it more tolerable. Magnesium and phosphate-based preps can achieve low volume, but they can be associated with multiple side effects, mainly electrolyte disturbances. Ultra low volume prep (NER1006) was achieved by combing PEG with ascorbic acid, and its efficacy and side effects were demonstrated in three noninferiority studies. CONCLUSION: It is important to consider patient preferences, co-morbidities and tolerability, and efficacy and side effect profiles when choosing bowel prep for patients undergoing colonoscopy. New ultra-low bowel prep showed promising results in initial clinical trials, but further real-world post-marketing data will inform its value in clinical practice.

Malathion insecticide resistance in Aedes aegypti: laboratory conditions and in situ experimental approach through adult entomological surveillance.

OBJECTIVE: In Brazil, the most common method of controlling outbreaks of arbovirus is by the use of chemical sprays, which kill the insect vector, Aedes aegypti. The main objective of this study was to evaluate the resistance of Ae. aegypti to the insecticide, malathion, in situ. The location of this study was the municipality of Foz do Iguaçu, in the state of Paraná, Brazil. METHODS: Ultra-low-volume (ULV) fogging equipment was used, by vehicle, to apply the insecticide in situ, and mosquito populations after treatment were compared with those of control areas. The resistance of strains collected from the municipality was compared to the Rockefeller strain under laboratory conditions. RESULTS: We found 220 adult female specimens and 7423 eggs of Ae. aegypti in the areas subjected to UBV treatment, whereas 245 adult females and 10 557 eggs were found in the control areas. The UBV treatment area showed no significant difference compared to the control area, for all the indices. Mortality of the Rockefeller colony varied more quickly when there were slight variations in malathion concentration than the Foz do Iguaçu population.

OBJECTIF: Au Brésil, la méthode la plus courante de lutte contre les épidémies d'arbovirus consiste à utiliser des pulvérisations chimiques qui tuent l'insecte vecteur, Aedes aegypti. L'objectif principal de cette étude était d'évaluer la résistance de Ae. aegypti à l'insecticide, le malathion, in situ. Le lieu de cette étude était la municipalité de Foz do Iguaçu, dans l'état du Paraná, au Brésil. MÉTHODES: Un équipement de brumisation à très faible volume (ULV) a été utilisé, par véhicule, pour appliquer l'insecticide in situ et les populations de moustiques après le traitement ont été comparées à celles des zones témoins. La résistance des souches collectées dans la municipalité a été comparée à la souche Rockefeller dans des conditions de laboratoire. RÉSULTATS: Nous avons trouvé 220 spécimens femelles adultes et 7.423 œufs d'Ae. aegypti dans les zones soumises au traitement ULV, alors que 245 femelles adultes et 10.557 œufs ont été trouvés dans les zones témoins. La zone de traitement ULV n'a montré aucune différence significative par rapport à la zone témoin, pour tous les indices. La mortalité de la colonie de Rockefeller variait plus rapidement lorsqu'il y avait de légères variations dans la concentration de malathion que la population de Foz do Iguaçu.

Intra-arterial computed tomography angiography with ultra-low volume of iodine contrast and stent implantation in transplant renal artery stenosis in terms of contrast-induced kidney injury - a preliminary report.

PURPOSE: Traditional digital subtraction angiography is still regarded as the gold standard in the diagnostics of transplant renal artery stenosis (TRAS). However, this procedure requires a high volume of iodine contrast medium for optimal visualisation of the renal artery. The aim of this study was to analyse both the usefulness and the safety of intra-arterial computed tomography angiography (IA-CTA) with ultra-low-volume iodine contrast administration in the diagnostic and therapeutic management of TRAS in patients with impaired renal transplant function. MATERIAL AND METHODS: Thirty-three patients with a suspicion of TRAS based on Doppler-ultrasound and clinical setting underwent IA-CTA with ultra-low iodine contrast volume. A special, author-elaborated CTA protocol was used. The volume of 8-18 ml of diluted iodine contrast medium was administered through a catheter with the tip placed 2 cm below the aortic bifurcation. RESULTS: In six patients the CTA examinations revealed TRAS in three configurations: in the anastomosis, in the trunk (critical and high-grade), or in both sections. Stenoses were treated with primary stenting obtaining favourable anatomical outcome. No intervention-related complications were observed. No contrast-induced acute kidney injury was diagnosed in this study. Mean serum creatinine concentration was 2.93 ± 0.89 mg/dl at the baseline and 2.89 ± 1.73 mg/dl and 2.17 ± 0.51 mg/dl after three and seven days from IA-CTA, respectively. CONCLUSIONS: Intra-arterial CTA with ultra-low volume of iodine contrast seems to be a safe and reliable diagnostic tool to detect and assess TRAS in the aspect of stent implantation. Application of this imaging modality eliminates the need for a high volume of iodine contrast and thus does not adversely influence renal transplant function.

Potential of Outdoor Ultra-Low-Volume Aerosol and Thermal Fog to Suppress the Dengue Vector, Aedes aegypti, Inside Dwellings.

A field study investigated penetration of outdoor ground ultra-low-volume (ULV) aerosol and thermal fog adulticide applications into a dwelling to control the dengue vector Aedes aegypti (L). Four applications of Kontrol 4-4 (4.6% permethrin active ingredient [AI], 4.6% piperonyl butoxide) at the maximum label rate were made at 25-30 m in front of a house at Camp Blanding Joint Training Center, Starke, FL, during summer 2016. The ULV sprayer and thermal fogger nozzles were oriented horizontally, and vehicle travel speeds were 16 and 24 km/h, respectively. All doors and windows of the house were left open. Spray efficacy was assessed using caged female mosquitoes positioned 30 cm above ground, outside and inside of the house. Interior cages were placed in open areas and cryptic sites (i.e., in a closet or cardboard box). A spinner holding 2 rods sized 3 mm × 75 mm was deployed next to each cage (except cryptic sites) to sample droplets and to quantify AI deposition. Thirty minutes after application, cages were removed, slides collected, and mosquitoes transferred to clean cages in the laboratory where mortality was assessed at 24 h posttreatment. The ULV application to the south side of the house produced 100% mortality in outdoor and indoor cages and 24% mortality at cryptic sites. Similarly applied thermal fog resulted in 85% mortality outdoors, 34% indoors, and only 4% in cages at cryptic sites. Application of either method from the west resulted in 19-61% mortality outdoors and 0.5-6.5% indoors. Droplet volume median diameter (Dv0.5) on rods from the ULV application was significantly larger compared with the thermal fogger outdoors, but similar indoors. Outdoors and indoors, the AI deposition from ULV was significantly higher than from thermal fog. Our results show the potential for controlling dengue vectors inside houses with outdoor ground ULV applications in areas where doors and windows are left open for ventilation.

Field Efficacy Trials of Aerial Ultra-Low-Volume Application of Insecticides Against Caged Aedes aegypti in Mexico.

We evaluated the efficacy of aerial ultra-low-volume (ULV) insecticide spraying in field bioassays with caged Aedes aegypti in May 2017 in Puerto Vallarta, Jalisco, Mexico. The insecticides tested included an organophosphate (Mosquitocida UNO ULV) and a neonicotinoid-pyrethroid combination (Cielo). Two Ae. aegypti populations were evaluated: a field pyrethroid-resistant local strain (Puerto Vallarta) and an insecticide-susceptible laboratory strain (New Orleans). Knockdown after 1 h by both products was ≥97.0%, and mortality after 24 h was ≥98% for the susceptible laboratory strain. Knockdown of the local Puerto Vallarta field strain by both products after 1 h was ≥96.5%; and mosquito mortality after 24 h was also very high (≥98%). Meteorological conditions during this evaluation were favorable for aerial mosquito control and represented conditions that typically occur during adulticide space spray applications. Temperature oscillated between 24°C and 26°C with winds between 6 and 10 km/h. The majority of droplets met the droplet distribution criteria required for the insecticides. The evaluation demonstrated an acceptable performance of both products for Ae. aegypti control when applied undiluted at a rate of 199.4 ml/ha and 73.07 ml/ha for Mosquitocida UNO ULV and Cielo, respectively. The volume median diameter (VMD) droplet size was characterized at 31.3 µm and 37.3 µm, respectively.

Entomological Efficacy of Aerial Ultra-Low Volume Insecticide Applications Against Aedes aegypti (Diptera: Culicidae) in Mexico.

A cluster-randomized controlled trial quantified the entomological efficacy of aerial ultra-low volume (AULV) applications of the insecticide chlorpyrifos against Aedes aegypti in Puerto Vallarta, México, during November-October 2017. The trial involved 16 large (1 × 1 km) clusters distributed between treatment-control arms. Primary endpoint was the abundance of Ae. aegypti indoors (total adults, females, and blood-fed females) collected using Prokopack aspirators. After four consecutive weekly cycles of AULV, all adult Ae. aegypti infestation indices were significantly lower in the treatment arm (OR and IRR ≤ 0.28). Efficacy in reducing indoor Ae. aegypti increased with each weekly application cycle from 30 to 73% (total adults), 33 to 76% (females), and 45.5 to 89% (blood-fed females). Entomological indices remained significantly lower in the treatment arm up to 2 wk after the fourth spraying round. Performing AULV spraying can have significant and lasting entomological impact on Ae. aegypti as long as multiple (ideally four) spray cycles are implemented using an effective insecticide.

An in vitro ULV olfactory bioassay method for testing the repellent activity of essential oils against moths.

A prototype olfactory device was developed and used for first time to study the bioactivity of Ultra Low Volumes (ULV) of three essential oilsagainst the moth pest Anarsia lineatella (Lepidoptera: Gelechiidae). Particle sizes calibration and standard ULV time-doses range tests were performed prior the olfactory bioassays. Three essential oils were tested Cymbopogon citratus (Lemon Grass), Gaultheria procumbens (Winter Grass) and Rosmarinus officinalis (Rosmarin) according to the proposed method. The most active oil was that of R. officinalis and moths expressed approximately 3-5 fold faster moving behavior (50% repellence response times to ULV, RT50: 20-30 min) compared to G. procumbens (RT50:74-79 min) and C. citratus (RT50:82-96 min). Apart from direct observed repellence, moths sprayed with ULV show clearly signs of knock down symptoms and high fatality in a period 15-60 min after their treatment especial in the case of R. officinalis. Longevity of female moths was significantly affected by the initial ULV application. Furthermore, choice test showed that essential oils significantly deterred oviposition in most cases. Considering the urgent need for alternative to conventional pesticides the current work may provide a framework of testing the bioactivity of bio rational compounds in the form of ULV and under Lab conditions.

Effect of Travel Speed on Dispersion of Aqualuer 20-20 Sprayed by a Truck-Mounted Ultra-Low-Volume Sprayer Against Caged Aedes aegypti1.

The effect of travel speed of a truck-mounted ultra-low-volume (ULV) sprayer on its application efficacy was studied at St. Johns County Fairground, Elkton, FL, during summer 2015. The efficacy was assessed by spray deposition, droplet size spectrum, and 24-h mortality of caged adult Aedes aegypti, using 2 rows of sampling locations, 15 m apart and spread up to 122 m from the spray. Each location had a bioassay cage and an impinger droplet sampler, 1 m apart from each other, at 1.5 m off the ground. Aqualuer® 20-20 (20.6% permethrin AI and 20% piperonyl butoxide) was applied at the maximum label rate, travelling at 8, 16, and 32 km/h. Three replications were completed on 3 days at least a week apart, with 1 replication of each travel speed per day. On each application day the travel speeds were rotated. Overall, a travel speed of 32 km/h achieved the highest efficacy of Aqualuer® 20-20, followed by 16 km/h, and then 8 km/h, in an open field. In general, droplet size, deposition, and mosquito mortality increased with increasing travel speed. The increased travel speed will also enhance the work rate of a sprayer and operator, thus reducing the cost of ULV applications.

Effect of Nozzle Orientation on Dispersion of Aqualuer 20-20 Sprayed by a Truck-Mounted Ultra-Low Volume Sprayer Against Caged Aedes aegypti.

Inconsistencies in efficacy of ultra-low volume (ULV) ground applications in the literature are linked to the lack of adjustments in sprayer parameters. To investigate the effect of nozzle orientation of a truck-mounted ULV sprayer on application efficacy, a study was conducted at St. Johns County Fairground, Elkton, FL, during the summer of 2014. The efficacy was assessed by mortality of caged adult Aedes aegypti, spray deposition, and droplet size spectrum up to 122 m from the spray line. Aqualuer 20-20 (20.6% permethrin active ingredient [AI] and 20% piperonyl butoxide [PBO]) was applied at the maximum label rate with the nozzle pointed 45° upward, horizontal (0°), or 30° downward. Mortality was recorded after 24 h, deposition was determined with fluorometry, and droplets were measured with DropVision. Overall, horizontal nozzle angle spraying Aqualuer 20-20 achieved the highest efficacy followed by a 30° downward angle, while a 45° angle showed the least efficacy in open field tests. The mortality data showed complete mortality from a 0° nozzle up to 122 m from the spray line except for 1 location at 122 m in 1 replication. The mortality from a 30° downward orientation was lower beyond 30 m from the spray line, while the mortality from a 45° upward orientation was low close to the spray line and beyond 30 m. Horizontal orientation had higher deposition than other orientations, but the differences were not significant. There was also no significant difference in droplet spectrum from all orientations.

Field Evaluation of Indoor Thermal Fog and Ultra-Low Volume Applications For Control of Aedes aegypti in Thailand.

Efficacies of a handheld thermal fogger (Patriot™) and a backpack ultra-low volume (ULV) sprayer (Twister™) with combinations of 2 different adulticides (pyrethrin, deltamethrin) and an insect growth regulator (pyriproxyfen) were field-tested and compared for their impact on reducing indoor Aedes aegypti populations in Thailand. The effectiveness of the indoor space sprays was evaluated by sampling the natural Ae. aegypti population in houses and determining their physiological status, by monitoring mortality of sentinel caged mosquitoes (AFRIMS strain) and by assessing larval mortality in laboratory bioassays using water exposed to the spray. A total of 14,742 Ae. aegypti were collected from Biogents Sentinel traps in this study. The combination of ULD® BP-300 (3% pyrethrin) and NyGuard® (10% pyriproxyfen) sprayed either by the Patriot or Twister significantly reduced some Ae. aegypti populations up to 20 days postspray relative to the control clusters. The addition of pyriproxyfen to the adulticide extended how long household mosquito populations were suppressed. In 2 of the 4 products being compared, the Twister resulted in higher mortality of caged mosquitoes compared with the Patriot. However, neither machine was able to achieve high mortality among Ae. aegypti placed in hidden (protected) cages. The larval bioassay results demonstrated that the Twister ULV provided better adult emergence inhibition than the Patriot (thermal fogger), likely due to larger droplet size.

Efficacy of Deltagard®, Fyfanon®, and Evoluer™ 31-66 Against Culex quinquefasciatus In Harris County, Texas.

The comparative efficacy of ultra-low volume applications of deltamethrin, permethrin, and malathion against specific adult populations of Culex quinquefasciatus , a primary regional vector of Saint Louis encephalitis and West Nile virus, using field cage tests is described. At labeled application rates, the estimated mass median diameters for Fyfanon®, Evoluer™, and DeltaGard® were 18.32, 19.24, and 17.44 µm, respectively. No significant differences (P ≥ 0.01) in mean percent control were observed across all 3 wild populations and a susceptible Sebring strain tested with Fyfanon, DeltaGard, and Evoluer, providing 98.25%, 98.20%, and 97.24% mean percent control. Mean percent control for Sebring and 3 wild populations was 99.38%, 97.79%, 97.26%, and 97.15%, respectively, which were not significantly different from one another (P ≥ 0.01). Across all tests, highly significant differences (P ≤ 0.01) in mean percent control were obtained at 30.48, 60.96, and 91.44 m distances downwind, with mean percent control at 91.44 m being significantly less than that observed at 30.48 m, but not at 60.96 m. Individually, tests for DeltaGard, Fyfanon, and Evoluer resulted in no significant differences (P ≥ 0.01) in mean percent control between all mosquito populations tested, ranging from 96.47 to 100. However, Evoluer obtained significantly less (P ≤ 0.01) mean percent control at 91.44 m compared to DeltaGard and Fyfanon. Data suggest that the wild Cx. quinquefasciatus specimens collected were as susceptible as the laboratory Sebring strain. The use of Sebring as positive controls downwind strongly supported determination of the efficacy of all adulticides and susceptibility of wild populations tested.

Limited impacts of truck-based ultra-low-volume applications of mosquito adulticides on mortality in honey bees (Apis mellifera).

Adulticides 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 (61 m had limited impacts on honey bee mortality while providing effective mosquito control.