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Sprayer comparisons and larval morality assays were conducted following SR450 backpack mist blower and Superhawk XP thermal fogger applications of Vectobac(registered trademark) WDG Bacillus thuringiensis israelensis (Bti) against Culex quinquefasciatus. Bacillus thuringiensis israelensis was applied at maximum label rate in a 232.26-sq m field plot located in north-central Florida with containers placed at 2 heights (ground level and 1.52 m above ground) on stakes positioned 3.04, 6.09, 9.14, 12.19, and 15.24 m from the spray line. Results indicated that there was no significant (P 0.05) difference in 24- and 48-h larval mortality between the 2 sprayers or between the 2 heights. There was significant difference (P 0.05) among the 5 rows, with mortality continuously decreasing with increasing distance from sprayer. Both sprayers provided on average 70% larval mortality 3.04-9.14 m from the spray line, and 60% mortality at 12.19 and 15.24 m. The data suggest that the SR450 and Superhawk XP may be comparable sprayers for use with Bti to control mosquito larvae., Published in Journal of the American Mosquito Control Association, v30 n3 p191-198, 2014.

Spray droplet size has long been recognized as an important variable that applicators of vector control sprays must be aware of to make the most effective spray applications. Researchers and applicators have several different techniques available to assess spray droplet size from spray nozzles. The objective of this study was to compare the droplet size spectrum produced by three nozzles commonly used in vector control in a high-speed wind tunnel, when characterized using three different laser-based droplet size measurement systems. Three droplet sizing systems: Malvern Spraytec laser diffraction, Sympatec HELOS laser diffraction, and TSI Phase Doppler Particle Analyzer (PDPA), were simultaneously operated, but under different operating conditions, to measure the spray droplet size-spectra for three spray nozzles. The three atomizers: a TeeJet 8001E even flat fan nozzle, a BETE PJ high pressure fog nozzles, and a Micronair AU5000 rotary atomizer were evaluated in a high speed wind tunnel at airspeeds of 53 and 62 m/s (120 and 140 mph). Based on the results of this work, only the BETE PJ high pressure fog nozzles met the label requirements for both Fyfanon and Anvil . While the other nozzle might met the Dv0.5 (VMD volume median diameter) requirement for Fyfanon , the resulting Dv0.9 values exceeded labeled size restrictions. When applying Anvil with the BETE PJ high pressure fog nozzles, it is important to use the smaller two orifice sizes. The larger sizes tended to result in Dv0.9 values that exceeded label recommendations., Published in the Journal of Plant Protection Research, v53 n3, 2013. Prepared in collaboration with the USDA-ARS, College Station, TX, Poznari University of Life Sciences, Poznari, Poland, the Lee County Mosquito Control District, Ft. Myers, FL, and Florida A&M University, Panama City.

Use of microscope slides is the most commonly used method to field-assess the droplet spectrum of ultra-low volume (ULV) sprays. Due to absence of analysis facilities during military deployments, slides must be stored and shipped, and the impact of delays in processing and storage conditions on droplets is unknown. This study was designed to evaluate the effect of storage temperatures and duration on droplets on TeflonH-coated slides. Treatments included BVA-13 mineral oil, Kontrol 30-30 (30% permethrin), and FyfanonH (96.5% malathion), 2 slide wrapping techniques (proper and improper), and 2 storage temperatures (23 and 45 deg C), replicated 6 times. The same areas of a slide were measured at different times for 56 58 days using the DropVisionH droplet measurement system. Regardless of the wrapping technique, droplets of BVA-13, Fyfanon, and Kontrol 30-30 on slides stored at 45 deg C reduced significantly after 1, 2, and 1 day, respectively, but droplets on slides stored at 23 deg C were not significantly affected. The results of this study may assist vector control professionals to accurately interpret the droplet size and help in the effective dispersal of ULV-applied insecticides., Published in the Journal of the American Mosquito Control Association, v29 n4 p389 392, 2013.

A high-throughput bioassay system to evaluate the efficacy of residual pesticides against mosquitoes and muscid flies with minimal insect handling was developed. The system consisted of 4 components made of readily available materials: 1) a CO2 anaesthetizing chamber, 2) a specialized aspirator 3) a cylindrical flat-bottomed glass bioassay chamber assembly, and 4) a customized rack., Pub. in Jounral of the American Mosquito Control Association, v29 n1, p84-87, 2013. Sponsored in part by Department of Defense.

In an effort to improve application methods for controlling sand flies in desert environments, a hand-held ultra-low volume (ULV) aerosol generator, a truck-mounted ULV aerosol generator, and a hand-held thermal fogger were evaluated. The velocity and temperature of the air and characteristics of droplets generated by these aerosol generators were measured at various distances from the nozzle. The droplet size characteristics were measured for three flow rates each of BVA-13 mineral oil and a mixture of water and nonionic surfactant with a phase Doppler particle analyzer. Moving 0.9 m away from the nozzle, the velocity of air produced by the two hand-held sprayers decreased to 5 m/s, whereas the truck-mounted sprayer still had an air velocity of 15 m/s. The air produced by truck-mounted cold fogger, thermal fogger and hand-held ULV applicator was 38, 49.2, and 8.5 deg C above ambient temperature respectively. Increases in flow rate, generally, did not affect the droplet size for the two hand-held units; however the droplet size increased as the flow rate increased on the truck- mounted sprayer. For all three aerosol generators droplet concentration increased with increasing flow rates. Both ULV generators showed an increase in droplet size and a decrease in droplet concentration as the distance from nozzle increased. However, the droplet size decreased and the droplet concentration increased when applied using the thermal fogger., Presented at Pesticide Formulations and Delivery Systems: Innovating Legacy Products for New Uses on November 1-3, 2011, Tampa, FL; STP 1558, 2012.

This work reports droplet-size data measured as part of a collaborative testing program between the US Department of Agriculture, Agricultural Research Service, and the US Navy, Navy Entomological Center for Excellence. This is an ongoing relationship that seeks to test new and revised spray technologies that may potentially be used by deployed personnel. As new equipment comes to market or when existing equipment is modified they are all integrated into this annual testing. During the 2011 equipment evaluations, 24 sprayers were operated across their range of available settings (pressure and flow rate), using both water and oil solutions. Droplet-size data as measured with laser diffraction ranged from 4 to 223 microns (volume median diameter). Generally, as the spray rate increased, droplet size increased, and as the pressure increased at a given same spray rate, droplet size decreased. This information allows users to set up and operate these sprayers in a manner such that a particular droplet size is applied optimizing efficiency and efficacy of applications., Journal of the American Mosquito Control Association, v28 n2 p93-101, 2012.

Near-ground aerosol fogs were applied in the Chihuahua Desert of New Mexico, which has widely spaced low shrub vegetation. Near-ground fog dispersion was measured remotely with a light detection and ranging (lidar) system. Local atmospheric turbulence and stability were continuously measured with 3-axis sonic anemometers during aerosol treatments. Lidar-measured plume area coverage and spread were related to the simultaneous local-scale weather including both convective boundary layers (CBL) and stable boundary layers (SBL). A modified bulk stability ratio (SRm) was used to characterize the stability conditions near the ground. Time averages appropriate to the SBL were determined using the multidimensional decomposition technique and matched to the short spray time periods in the CBL. The widest most effective, near-ground coverage was obtained from insect fogger applications conducted during relatively high wind speeds: U 1 m s-1 in stable conditions, and U 3 m s-1 in unstable conditions. In general, spraying during SBLs was more efficient than during CBLs, with less material wasted and better consistency of coverage in the target zone nearest the ground. There was no significant difference in spray coverage or plume dispersion between the handheld thermal fogger and the ultra-low volume (cold fogger) applicator used., Pub. in Transactions of the ASABE, v55 n2 p351-361, 2012.

Reducing populations of phlebotomine sand flies in areas prevalent for human leishmaniases is of ongoing importance to United States military operations and civilian populations in endemic regions. However, not enough is known regarding the efficacy of Department of Defense-approved pesticides and equipment against sand flies; specifically, the potential for ultra-low volume (ULV) pesticide applications to control Old World sand fly vectors. In this study we examine two sprayers, the Terminator ULV and the Grizzly ULV, with UV-labeled Duet and Fyfanon in four combinations against caged Phlebotomus duboscqi (Neveu-Lemaire) and wild sand fly populations in a natural environment in western Kenya. All equipment and Fyfanon have United States military National Stock Numbers and both pesticides are registered with the United States Environmental Protection Agency. Caged sand flies were reared from local P. duboscqi and the area has long been studied because of high incidences of human cutaneous and visceral Leishmania. Patterns of mortality across grids of caged sand flies showed greater efficacy from the Grizzly ULV regardless of chemical. The Terminator ULV performed well with Duet but with a less uniform and overall lower rate of mortality across the spray grid. Sampling of wild populations before and after treatments suggested local population suppression from ULV treatments, as well as a possible repellent effect in nearby untreated areas. Surprisingly, ULV active ingredient deposition inferred from patterns of UV-labeled droplets captured on cotton ribbons adjacent to sand fly cages in spray plots did not match patterns of mortality. We discuss the implications of this study, the first of its kind, for future military preventive medicine activities, including relative performance costs and benefits of larger or smaller sprayers, and the relative stability of ULV-induced mortality patterns in varied or sub-optimal conditions., Published in the Journal of Medical Entomology, v48 n6 p1145-1159, 2011. Sponsored in part by the U.S. Department of Agriculture (USDA) Agricultural Research Service. Prepared in collaboration with the Army Medical Research Unit-Kenya and the United States Department of Agriculture, Agricultural Research Service, Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, FL.

A study was conducted to analyze the performance of 3 electrostatic (Electrolon BP-2.5TM Spectrum Electrostatic 4010, and Spectrum Electrostatic head on a Stihl 420) and 2 conventional (Buffalo Turbine CSM2 and Stihl 420) sprayers for barrier sprays to suppress an adult mosquito population in an enclosed area. Sprayer characteristics such as charge-mass ratio, air velocity, flow rate, and droplet spectra were measured while spraying water. Dispersion of the spray cloud from these sprayers was determined using coverage on water-sensitive cards at various heights (0.5 m, 1.0 m, 1.5 m, 2.0 m, 2.5 m, and 3.0 m) and depths (1 m, 3 m, and 5 m) into the under-forest vegetation while spraying bifenthrin (TalstarTM 7.9% AI; FMC Corporation, Philadelphia, PA) at the rate of 21.8 ml/300 m of treated row. The charge-mass ratio data show that Electrostatic head on a Stihl 420 did not impart enough charge to the droplets to be considered as an electrostatic sprayer. In general, the charged spray cloud moved down toward the ground. The Electrolon BP 2.5 had significantly lower spray coverage on cards, indicating lack of spray dispersion. This sprayer had the lowest air velocity and did not have the air capacity needed to deliver droplets close to the target for electrostatic force to affect deposition. The analysis shows that these 2 sprayers are not a suitable choice for barrier sprays on vegetation. The results indicate that the Buffalo Turbine is suitable for barriers wider than 3 m, and the Spectrum 4010 and Stihl 420 are suitable for 1-3 m wide barriers., Published in the Journal of the American Mosquito Control Association, v26 n4 p422-429, Dec 2010.

Treating perimeters of vegetation with residual insecticides for protection from mosquito vectors has potential for U.S. military force health protection. However, for current U.S. military operations in hot-arid environments with little or no vegetation, residual applications on portable artificial materials may be a viable alternative. We evaluated bifenthrin residual treatments of U.S. military camouflage netting under hot-arid field conditions in a desert area in southern California exposed to abundant wild Culex mosquitos., Published in Military Medicine, v175 n8 p599-606, 2010. Prepared in cooperation with Department of Agriculture, Gainesville, FL; Coaghella Valley Mosquito and Vector Control District, Indio, CA; and others.

Ultra-low-volume (ULV) and thermal fog aerosol dispersals of pesticides have been used against mosquitoes and other insects for half a century. Although each spray technology has advantages and disadvantages, only 7 studies have been identified that directly compare their performance in the field. US military personnel currently operating in hot-arid environments are impacted by perpetual nuisance and disease vector insect problems, despite adulticide operations using modern pesticide-delivery equipment such as ULV. None of the identified comparative studies has looked at the relative feasibility and efficacy of ULV and thermal fog equipment against mosquitoes in hot-arid environments. In this study we examine the impact of ULV and thermal fog applications of malathion against caged sentinel mosquitoes in the field in a warm temperate area of Florida, followed by a similar test in a hot-dry desert area of southern California. Patterns of mortality throughout 150 m 3 150 m grids of sentinel mosquitoes indicate greater efficacy from the thermal fog application in both environments under suboptimal ambient weather conditions. We discuss the implications of these findings for future military preventive medicine activities and encourage further investigations into the relative merits of the 2 technologies for force health protection., Sponsored in part by Department of Agriculture. Pub. in the Journal of the American Mosquito Control Association, v26 n2, p183-197, 2010.

Ultra-low-volume (ULV) and thermal fog aerosol dispersals of pesticides have been used against mosquitoes and other insects for half a century. Although each spray technology has advantages and disadvantages, only 7 studies have been identified that directly compare their performance in the field. US military personnel currently operating in hot-arid environments are impacted by perpetual nuisance and disease vector insect problems, despite adulticide operations using modern pesticide-delivery equipment such as ULV. None of the identified comparative studies has looked at the relative feasibility and efficacy of ULV and thermal fog equipment against mosquitoes in hot-arid environments. In this study we examine the impact of ULV and thermal fog applications of malathion against caged sentinel mosquitoes in the field in a warm temperate area of Florida, followed by a similar test in a hot-dry desert area of southern California. Patterns of mortality throughout 150 m × 150 m grids of sentinel mosquitoes indicate greater efficacy from the thermal fog application in both environments under suboptimal ambient weather conditions. We discuss the implications of these findings for future military preventive medicine activities and encourage further investigations into the relative merits of the 2 technologies for force health protection.

Numerous spray machines are used to apply pesticides for the control of human disease vectors, such as mosquitoes and flies, and the selection and setup of these machines significantly affects the level of control achieved during an application. The droplet spectra produced by 9 different ultra-low? volume sprayers with oil- and water-based spray solutions were evaluated along with 2 thermal foggers with the use of diesel-based spray solutions. The droplet spectra from the sprayers were measured with the use of laser diffraction droplet sizing equipment. The volume median diameter from the sprayers ranged from 14.8 to 61.9 mm for the oil-based spray solutions and 15.5 to 87.5 mm for the water-based spray solutions. The 2 thermal foggers generated sprays with a volume median diameter of 3.5 mm. The data presented will allow spray applicators to select the spray solution and sprayer that generate the droplet-size spectra that meet the desired specific spray application scenarios., Pub. in Journal of the American Mosquito Control Association, v25 n3, p332-337, 2009.

Treating perimeters with residual insecticides for protection from mosquito vectors has shown promise. These barrier treatments are typically evaluated in temperate or tropical areas using abundant vegetation as a substrate. However, there is an emerging interest to develop this technology to protect deployed US troops in extreme desert environments with sparse vegetation. We used a remote desert area in the Coachella Valley, California, to 1) evaluate bifenthrin barrier treatments on native xeric vegetation and 2) compare treatments applied with electrostatic and conventional spray technologies. Through a combination of laboratory bioassays on treated and control vegetation sampled at specific intervals over 63 days, synchronized with field surveillance of mosquitoes, we measured the temporal pattern of bioactivity of bifenthrin barriers under natural hot, dry, and dusty desert conditions. Regardless of spray technology, mosquito catch in treated plots was about 80% lower than the catch in control plots 1 day after treatment. This reduction in mosquito numbers in treated plots declined each week after treatment but remained at about 40% lower than control plots after 28 days. Field data were corroborated by results from bioassays that showed significantly higher mosquito mortality on treated vegetation over controls out to 28 days postspray. We concluded that barrier treatments in desert environments, when implemented as part of a suite of integrated control measures, may offer a significant level of protection from mosquitoes for deployed troops. Given the comparable performance of the tested spray technologies, we discuss considerations for choosing a barrier treatment sprayer for military scenarios., Published in the Journal of the American Mosquito Control Association v25 n2 p184-193, 2009.

A comparison of nine commercial baited fly traps on Florida dairy farms demonstrated that Terminator traps collected significantly more (13,323/trap) house flies (Musca domestica L.) than the others tested. Final Flight, Fly Magnet, and FliesBeGone traps collected intermediate numbers of flies (834-2,166), and relatively few were caught with ISCA, Advantage, Fermone Big Boy, Squeeze & Snap, or OakStump traps (<300). Terminator traps collected about twice as many flies (799.8/trap) as FliesBeGone traps (343.8) when each trap was baited with its respective attractant, but when the attractants were switched between the two trap types, collections were significantly lower (77-108) than was observed with traps baited with their respective attractant. Solutions of molasses were significantly more attractive to house flies than honey, maple syrup, or jaggery (date palm sugar). Field-expedient traps constructed from discarded PET water bottles were much less effective than commercial traps, but painting the tops of such traps with black spray paint resulted in a six-fold increase in trap capture., Published in Journal of Vector Ecology, v34 n1 p99-103, June 2009.

The atomization characteristics of 4 handheld sprayers (Leco P-l, Colt ULV Aerosol Generator, ULVAFAN MK2, Turbair ElectraFan 12) and a Stihl SR400 backpack sprayer were evaluated with the use of water and oil-based solutions. The effects on droplet-size spectrum (i.e., droplet size) for 3 insecticides (Tempo SC Ultra(R), Anvil 10+10(R), and Aqua-Reslin(R)) were also evaluated. Generic solutions were used to simulate the physical properties of the active-ingredient solutions in some tests. Significant differences were observed in the droplet spectrum generated by the different sprayers. The volume median diameter of the equipment tested ranged from 14.9 to 90.5 gm for the water-based solutions and from 11.7 to 92.4 tm for the oil-based solutions. The Colt ULV sprayer was the only one tested that complied with label requirements for aerosols, yielding acceptable Dv0.5 values of 14.9-16.0 lam with water-based Aqua-Reslin and 14.1 [am with Anvil 10+10. The information presented will allow equipment operators to make an informed decision when selecting equipment and operational parameters., Pub. in Journal of the American Mosquito Control Association, v23 n3, p315-320, 2007.