scholarly journals A Yeast RNA-Interference Pesticide Targeting the Irx Gene Functions as a Broad-Based Mosquito Larvicide and Adulticide

Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 986
Author(s):  
Keshava Mysore ◽  
Longhua Sun ◽  
Limb K. Hapairai ◽  
Chien-Wei Wang ◽  
Jessica Igiede ◽  
...  
Keyword(s):  
Mosquito Control ◽  
Field Trials ◽  
Proneural Gene ◽  
Hairpin Rna ◽  
Nontarget Organisms ◽  
Rnai Technology ◽  
Control Paradigm ◽  
Control Intervention ◽  
Simulated Field ◽  
Further Development

Concerns for widespread insecticide resistance and the unintended impacts of insecticides on nontarget organisms have generated a pressing need for mosquito control innovations. A yeast RNAi-based insecticide that targets a conserved site in mosquito Irx family genes, but which has not yet been identified in the genomes of nontarget organisms, was developed and characterized. Saccharomyces cerevisiae constructed to express short hairpin RNA (shRNA) matching the target site induced significant Aedes aegypti larval death in both lab trials and outdoor semi-field evaluations. The yeast also induced high levels of mortality in adult females, which readily consumed yeast incorporated into an attractive targeted sugar bait (ATSB) during simulated field trials. A conserved requirement for Irx function as a regulator of proneural gene expression was observed in the mosquito brain, suggesting a possible mode of action. The larvicidal and adulticidal properties of the yeast were also verified in Aedes albopictus, Anopheles gambiae, and Culexquinquefasciatus mosquitoes, but the yeast larvicide was not toxic to other nontarget arthropods. These results indicate that further development and evaluation of this technology as an ecofriendly control intervention is warranted, and that ATSBs, an emerging mosquito control paradigm, could potentially be enriched through the use of yeast-based RNAi technology.

scholarly journals A Broad-Based Mosquito Yeast Interfering RNA Pesticide Targeting Rbfox1 Represses Notch Signaling and Kills Both Larvae and Adult Mosquitoes

Pathogens ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1251
Author(s):  
Keshava Mysore ◽  
Longhua Sun ◽  
Limb K. Hapairai ◽  
Chien-Wei Wang ◽  
Joseph B. Roethele ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Mosquito Control ◽  
Field Trials ◽  
New Paradigm ◽  
Control Programs ◽  
Rnai Technology ◽  
Impact On Survival ◽  
Environmentally Safe ◽  
Control Technologies ◽  
Interfering Rna

Prevention of mosquito-borne infectious diseases will require new classes of environmentally safe insecticides and novel mosquito control technologies. Saccharomyces cerevisiae was engineered to express short hairpin RNA (shRNA) corresponding to mosquito Rbfox1 genes. The yeast induced target gene silencing, resulting in larval death that was observed in both laboratory and outdoor semi-field trials conducted on Aedes aegypti. High levels of mortality were also observed during simulated field trials in which adult females consumed yeast delivered through a sugar bait. Mortality correlated with defects in the mosquito brain, in which a role for Rbfox1 as a positive regulator of Notch signaling was identified. The larvicidal and adulticidal activities of the yeast were subsequently confirmed in trials conducted on Aedes albopictus, Anopheles gambiae, and Culex quinquefasciatus, yet the yeast had no impact on survival of select non-target arthropods. These studies indicate that yeast RNAi pesticides targeting Rbfox1 could be further developed as broad-based mosquito larvicides and adulticides for deployment in integrated biorational mosquito control programs. These findings also suggest that the species-specificity of attractive targeted sugar baits, a new paradigm for vector control, could potentially be enhanced through RNAi technology, and specifically through the use of yeast-based interfering RNA pesticides.

scholarly journals Development of a Colorimetric Sensor for Autonomous, Networked, Real-Time Application

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5857
Author(s):  
Brandy J. Johnson ◽  
Anthony P. Malanoski ◽  
Jeffrey S. Erickson
Keyword(s):  
Real Time ◽  
Field Trials ◽  
Wireless Sensor ◽  
Broad Area ◽  
Ongoing Effort ◽  
Environmental Air ◽  
Further Development ◽  
Real Time Application ◽  
Selection Of ◽  
Event Occurrence

This review describes an ongoing effort intended to develop wireless sensor networks for real-time monitoring of airborne targets across a broad area. The goal is to apply the spectrophotometric characteristics of porphyrins and metalloporphyrins in a colorimetric array for detection and discrimination of changes in the chemical composition of environmental air samples. The work includes hardware, software, and firmware design as well as development of algorithms for identification of event occurrence and discrimination of targets. Here, we describe the prototype devices and algorithms related to this effort as well as work directed at selection of indicator arrays for use with the system. Finally, we review the field trials completed with the prototype devices and discuss the outlook for further development.

Comparison of the Effect of Insecticides on Bumble Bees (Bombus impatiens) and Mosquitoes (Aedes aegypti and Culex quinquefasciatus) by Standard Mosquito Research Methods

2020 ◽  
Author(s):  
Bethany L McGregor ◽  
Bryan V Giordano ◽  
Alfred E Runkel ◽  
Herbert N Nigg ◽  
H Lee Nigg ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Culex Quinquefasciatus ◽  
Mosquito Control ◽  
The United States ◽  
Field Trials ◽  
Bombus Impatiens ◽  
Acute Effects ◽  
Nontarget Effects ◽  
Native North American ◽  
Significant Mortality

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.

scholarly journals A transgenic approach for controlling Lygus in cotton

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Anilkumar Gowda ◽  
Timothy J. Rydel ◽  
Andrew M. Wollacott ◽  
Robert S. Brown ◽  
Waseem Akbar ◽  
...  
Keyword(s):  
Insecticidal Activity ◽  
The United States ◽  
Field Trials ◽  
Transgenic Cotton ◽  
Economic Losses ◽  
Bt Cotton ◽  
Transgenic Event ◽  
Plant Feeding ◽  
Whole Plant ◽  
Further Development

Abstract Lygus species of plant-feeding insects have emerged as economically important pests of cotton in the United States. These species are not controlled by commercial Bacillus thuringiensis (Bt) cotton varieties resulting in economic losses and increased application of insecticide. Previously, a Bt crystal protein (Cry51Aa2) was reported with insecticidal activity against Lygus spp. However, transgenic cotton plants expressing this protein did not exhibit effective protection from Lygus feeding damage. Here we employ various optimization strategies, informed in part by protein crystallography and modelling, to identify limited amino-acid substitutions in Cry51Aa2 that increase insecticidal activity towards Lygus spp. by >200-fold. Transgenic cotton expressing the variant protein, Cry51Aa2.834_16, reduce populations of Lygus spp. up to 30-fold in whole-plant caged field trials. One transgenic event, designated MON88702, has been selected for further development of cotton varieties that could potentially reduce or eliminate insecticide application for control of Lygus and the associated environmental impacts.

Not a load of rubbish: simulated field trials in large-scale containers

2016 ◽  
Vol 39 (9) ◽  
pp. 2064-2073 ◽  
Author(s):  
M. Hohmann ◽  
A. Stahl ◽  
J. Rudloff ◽  
B. Wittkop ◽  
R. J. Snowdon
Keyword(s):  
Large Scale ◽  
Field Trials ◽  
Simulated Field

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
Keyword(s):  
Aedes Albopictus ◽  
High Performance ◽  
Mosquito Control ◽  
Field Trials ◽  
Percent Reduction ◽  
Mosquito Abundance ◽  
Laboratory Results ◽  
High Label ◽  
Laboratory Bioassays ◽  
Low Rate

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.

LACK OF EFFECTS OF BACILLUS SPHAERICUS (VECTOLEX®) ON NONTARGET ORGANISMS IN A MOSQUITO-CONTROL PROGRAM IN SOUTHEASTERN WISCONSIN: A 3-YEAR STUDY

2005 ◽  
Vol 21 (2) ◽  
pp. 201-212 ◽  
Author(s):  
Richard W. Merritt ◽  
Joanna L. Lessard ◽  
Kelly J. Wessell ◽  
Osvaldo Hernandez ◽  
Martin B. Berg ◽  
...  
Keyword(s):  
Mosquito Control ◽  
Control Program ◽  
Bacillus Sphaericus ◽  
Nontarget Organisms

scholarly journals Aedes aegypti Males as Vehicles for Insecticide Delivery

Insects ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 230 ◽  
Author(s):  
Corey L. Brelsfoard ◽  
James W. Mains ◽  
Steve Mulligan ◽  
Anthony Cornel ◽  
Jodi Holeman ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Mosquito Control ◽  
Field Trials ◽  
Larval Survival ◽  
Initial Field ◽  
Breeding Sites ◽  
Larval Habitats ◽  
Control Techniques ◽  
Oviposition Sites ◽  
Lethal Doses

Aedes aegypti continues to spread globally and remains a challenge to control, in part due to its ‘cryptic behavior’ in that it often deposits eggs (oviposits) in larval habitats that are difficult to find and treat using traditional methods. Auto-dissemination strategies target these cryptic breeding sites by employing mosquitoes to deliver lethal doses of insecticide. This report describes the initial field trials of an application known as Autodissemination Augmented by Males (ADAM), utilizing A. aegypti males dusted with pyriproxyfen (PPF). Findings presented here are drawn from both caged and field trial studies. Together, these trials examined for the ability of A. aegypti males to disseminate PPF and to impact field populations. PPF-dusted males were able to effectively deliver lethal doses of PPF to oviposition sites under the conditions tested. Results from field trials in Florida and California demonstrated reduced A. aegypti populations in treated areas, compared to areas where PPF-treated males were not released. These results indicate that the release of PPF-dusted A. aegypti males can impact A. aegypti populations as measured by both reduced larval survival and lower numbers of adult female A. aegypti. We propose the ADAM approach as an addition to existing mosquito control techniques targeting A. aegypti and other mosquitoes that utilize cryptic larval habitats.

THE EFFECT OF PARTIAL STERILIZATION OF FIELD SOILS BY CHEMICALS UPON DIFFERENTIAL MICROBIAL COUNTS, CO2 ACTIVITY, AND RATES OF ORGANIC MATTER DECOMPOSITION

1960 ◽  
Vol 6 (3) ◽  
pp. 339-347 ◽  
Author(s):  
Gerald H. Elkan ◽  
W. E. C. Moore
Keyword(s):  
Organic Matter ◽  
Biological Activity ◽  
Mercuric Chloride ◽  
Field Trials ◽  
Organic Matter Decomposition ◽  
Sodium Propionate ◽  
Calcium Hypochlorite ◽  
Chemical Treatments ◽  
Partial Sterilization ◽  
Further Development

Varying dosage rates of calcium hypochlorite, mercuric chloride, and sodium propionate were used as partial sterilization agents in field and greenhouse trials to determine the effect on soil biological activity, and thereby, organic matter decomposition rates. Application of the chemicals often resulted in the initial stimulation of respiration rates. In greenhouse and field trials this stimulation was most commonly associated with the application of sodium propionate. Fungal counts decreased and bacterial counts increased when this chemical was used. Within 4 weeks after treatment, all rates of application of the various chemicals depressed soil CO2 evolution. Thirteen months after treatment, plots treated with 100 lb of mercuric chloride per acre had one quarter as many actinomycetes and total microbes, and one third as many fungi, as did the control plots. Respiration was also considerably lower. Calcium hypochlorite treated plots retained reduced total counts and sodium propionate reduced fungal counts. Respiration in these last plots was not depressed.The changes in organic matter decomposition due to chemical treatments were not statistically significant in the greenhouse or field studies.General lack of correlation between the three measures of biological activity used in this study indicate the necessity for the further development of methods for measuring the population of microorganisms in soil.

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