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 ◽  
...  

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.

Author(s):  
Daniel Dixon

Aedes aegypti is an anthropophilic vector of several arboviruses, including yellow fever, Dengue virus, Chikungunya virus, and the infamous Zika virus. In 2016, Zika virus was spreading rapidly throughout Brazil and mosquito control districts expected Zika virus would be imported to Florida and vectored by endemic Aedes aegypti. Aedes aegypti often takes advantage of cryptic oviposition sites and therefore circumvents conventional control and surveillance strategies used by mosquito control practitioners. The objective of this study was to find Ae. aegypti breeding sites in the tourist district of Saint Augustine, FL, using a door-to-door on-foot approach. Mosquito control technicians, biologists and interns worked to inspect and treat each property for Ae. aegypti. Additionally, residents were informed about Ae. aegypti and its public health risk factors. In total, Anastasia Mosquito Control District inspected 1199 of the 1995 parcels in downtown Saint Augustine (60% coverage) in three months. Artificial containers were found at 1,099 of the homes inspected, and Ae. aegypti were found at 120 homes in the area. Each property where mosquito larvae and/or adults were detected was treated using source reduction, larvicides and adulticides. Residents were educated about this project and Ae. aegypti via small flyers, door hangers, pamphlets and/or verbal communication. This study provided insight into the location of Ae. aegypti breeding sites in the tourist district of Saint Augustine, FL, which will facilitate future control efforts.


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.


Insects ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 663
Author(s):  
Kenia Mayela Valdez-Delgado ◽  
David A. Moo-Llanes ◽  
Rogelio Danis-Lozano ◽  
Luis Alberto Cisneros-Vázquez ◽  
Adriana E. Flores-Suarez ◽  
...  

Aedes aegypti control programs require more sensitive tools in order to survey domestic and peridomestic larval habitats for dengue and other arbovirus prevention areas. As a consequence of the COVID-19 pandemic, field technicians have faced a new occupational hazard during their work activities in dengue surveillance and control. Safer strategies to monitor larval populations, in addition to minimum householder contact, are undoubtedly urgently needed. Drones can be part of the solution in urban and rural areas that are dengue-endemic. Throughout this study, the proportion of larvae breeding sites found in the roofs and backyards of houses were assessed using drone images. Concurrently, the traditional ground field technician’s surveillance was utilized to sample the same house groups. The results were analyzed in order to compare the effectiveness of both field surveillance approaches. Aerial images of 216 houses from El Vergel village in Tapachula, Chiapas, Mexico, at a height of 30 m, were obtained using a drone. Each household was sampled indoors and outdoors by vector control personnel targeting all the containers that potentially served as Aedes aegypti breeding sites. The main results were that the drone could find 1 container per 2.8 found by ground surveillance; however, containers that were inaccessible by technicians in roofs and backyards, such as plastic buckets and tubs, disposable plastic containers and flowerpots were more often detected by drones than traditional ground surveillance. This new technological approach would undoubtedly improve the surveillance of Aedes aegypti in household environments, and better vector control activities would therefore be achieved in dengue-endemic countries.


2008 ◽  
Vol 33 (1) ◽  
pp. 76-88 ◽  
Author(s):  
Adriana Troyo ◽  
Olger Calderón-Arguedas ◽  
Douglas O. Fuller ◽  
Mayra E. Solano ◽  
Adrian Avendaño ◽  
...  

2021 ◽  
Author(s):  
Danilo Freire ◽  
Umberto Mignozzetti

Background. Mosquito control is the most effective means of reducing A. aegypti infections worldwide. In many developing countries, however, vector management programmes fail to reach their goals due to low worker productivity. Research suggests that financial incentives may increase the productivity of health personnel, yet there is little evidence about the impact of monetary rewards on A. aegypti-reduction strategies. We evaluated whether individual and collective financial incentives improve the performance of healthcare workers fighting A. aegypti, as well as their effect on city-level numbers of dengue hospitalisations. Methodology/Principal findings. We hired and trained subjects to visit households, find A. aegypti breeding sites, and eliminate mosquito larvae in the city of Rio Verde, Brazil. We randomly assigned workers into three groups. The control group received a flat compensation for their tasks, while workers in the two treatment groups received individual and collective monetary bonuses, respectively. Financial rewards increased the number of cleaned breeding sites in both treatment groups (individual and team bonuses) and the collective treatment also improved larvae extermination. The intervention lowered dengue hospitalisations in 10.3%, but the result was not consistent across all model specifications. Conclusions/Significance. A. aegypti control programmes may benefit from alternative compensation schemes, specially when provided to teams. For this strategy to succeed, financial incentives have to be distributed widely as their aggregate effect is limited. More research is needed to assess whether higher worker productivity decreases dengue hospitalisations. Keywords: Aedes aegypti, dengue, financial incentives, mosquito control, preventive healthcare, randomised field experiment, worker productivity


2019 ◽  
Author(s):  
Rachel Sippy ◽  
Galo E. Rivera ◽  
Valeria Sanchez ◽  
Froilán Heras Heras ◽  
Bianca Morejón ◽  
...  

AbstractBackgroundIllnesses transmitted by Aedes aegypti (Linnaeus, 1762) such as dengue, chikungunya and Zika comprise a considerable global burden; mosquito control is the primary public health tool to reduce disease transmission. Current interventions are inadequate and insecticide resistance threatens the effectiveness of these options. Dried attractive bait stations (DABS) are a novel mechanism to deliver insecticide to Ae. aegypti. The DABS are a high-contrast 28 inch2 surface coated with dried sugar-boric acid solution. Ae. aegypti are attracted to DABS by visual cues only, and the dried sugar solution elicits an ingestion response from Ae. aegypti landing on the surface. The study presents the development of the DABS and tests of their impact on Ae. aegypti mortality in the laboratory and a series of semi-field trials.MethodsWe conducted multiple series of laboratory and semi-field trials to assess the survivability of Ae. aegypti mosquitoes exposed to the DABS. For laboratory experiments we assessed the lethality, the killing mechanism, and the shelf life of the device through controlled experiments. In the semi-field trials, we released laboratory-reared female Ae. aegypti into experimental houses typical of peri-urban tropical communities in South America in three trial series with six replicates each. Laboratory experiments were conducted in Quito, Ecuador, and semi-field experiments were conducted in Machala, Ecuador – an area with abundant wild populations of Ae. aegypti and endemic arboviral transmission.ResultsIn the laboratory, complete lethality was observed after 48 hours regardless of physiological status of the mosquito. The killing mechanism was determined to be through ingestion, as the boric acid disrupted the gut of the mosquito. In experimental houses, total mosquito mortality was greater in the treatment house for all series of experiments (p<0.0001).ConclusionsThe DABS devices were effective at killing female Ae. aegypti under a variety of laboratory and semi-field conditions. DABS are a promising intervention for interdomiciliary control of Ae. aegypti and arboviral disease prevention.


2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Abdurrakhman abdurrakhman Abdurrakhman

ABSTRACT : The House index and Container Index in the buffer area of ​​the working area of ​​Balikpapan Sepinggan Airport is still above 1%, so the potential for the spread of dengue disease. Mobilization of people, goods and transportation equipment will increasingly affect the transmission of disease in ports and airports, especially for vector-borne diseases. This study aims to analyze the risk factors associated with larvae density of Aedes aegypti and describe the larvae index in the buffer zone of the Sepinggan Balikpapan Airport This study was a descriptive study with a cross sectional design. The sample in this study was 121 houses with a proportionate stratified random sampling, the research location was in the buffer zone of Sepinggan Balikpapan Airport in November 2018. The variables studied were houses with positive larvae containers, breeding sites and PSN behavior and larvasidation. The data was analyzed using the chi square test. There was a relationship between houses with larvae positive Aedes aegypti, behavior of Mosquito Nest Eradication (PSN) and larvasidation with larvae density of Aedes aegypti but not for breeding sites (p = 0.00 and 95% CI = 0.64), and   (p = 0.00 and 95% CI = 0.34). The description of several Aedes aegypti larvae index, namely House Index (HI) = 57.02%, Container Index (CI) = 24.36%, Bruteau Index (BI) = 148.76, and Flick Free Numbers (ABJ) = 42.98 %. Houses with larvae of Aedes aegypti larvae and PSN and larvasidation behavior were associated with larvae density of Aedes aegypti. The index of HI, CI and BI larvae is of high value so there is a risk of DBD transmission


Author(s):  
Ambar Widianingrum ◽  
Joko Sulianto ◽  
Rahmat Rais

The purpose of this study was to describe the feasibility of teaching materials based on an open-ended approach to improve the reasoning abilities of fourth grade students in elementary schools. This type of research is research and development (Research and Development). The subjects of this study were 3 classroom teachers. The data analysis technique used is descriptive qualitative data analysis (data reduction, data presentation and conclusion) and quantitative descriptive data analysis. Based on the results of stage 1 media validation, it was obtained 84.8%, and the results of stage 2 media validation were obtained 94.8%. The result of material validation for stage 1 was obtained 84.6%, and validation for material for stage 2 was obtained 93.3%. The results of initial field trials obtained media 93.7% and material 92.3%. This shows that the teaching material is declared valid and suitable for use. Based on the results of this study, the suggestion that can be conveyed is that teaching materials based on an open-ended approach can be used as a tool for teaching and learning resources for students.


Author(s):  
Md. Sahidur Rahman ◽  
Md. Omar Faruk ◽  
Sumiya Tanjila ◽  
Nur Mohammad Sabbir ◽  
Najmul Haider ◽  
...  

Abstract Background Studying the characteristics of Aedes mosquito habitats is essential to control the mosquito population. The objective of this study was to identify the breeding sites of Aedes larvae and their distribution in Chattogram, Bangladesh. We conducted an entomological survey in 12 different sub-districts (Thana) under Chattogram City, during the late monsoon (August to November) 2019. The presence of different wet containers along with their characteristics and immature mosquitoes was recorded in field survey data form. Larvae and/or pupae were collected and brought to the laboratory for identification. Results Different indices like house index, container index, and the Breteau index were estimated. The multiple logistic regression analysis was applied to identify habitats that were more likely to be positive for Aedes larvae/pupae. A total of 704 wet containers of 37 different types from 216 properties were examined, where 52 (7.39%) were positive for Aedes larvae or pupae. Tire, plastic buckets, plastic drums, and coconut shells were the most prevalent container types. The plastic group possessed the highest container productivity (50%) whereas the vehicle and machinery group was found as most efficient (1.83) in terms of immature Aedes production. Among the total positive properties, 8% were infested with Aedes aegypti, 2% with Aedes albopictus, and 1% contained both species Ae. aegypti and A. albopictus. The overall house index was 17.35%, the container index was 7%, and the Breteau index was 24.49. Containers in multistoried houses had significantly lower positivity compared to independent houses. Binary logistic regression represented that containers having shade were 6.7 times more likely to be positive than the containers without shade (p< 0.01). Conclusions These findings might assist the authorities to identify the properties, containers, and geographical areas with different degrees of risk for mosquito control interventions to prevent dengue and other Aedes-borne disease transmissions.


Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 71
Author(s):  
Tse-Yu Chen ◽  
Chelsea T. Smartt ◽  
Dongyoung Shin

Aedes aegypti, as one of the vectors transmitting several arboviruses, is the main target in mosquito control programs. Permethrin is used to control mosquitoes and Aedes aegypti get exposed due to its overuse and are now resistant. The increasing percentage of permethrin resistant Aedes aegypti has become an important issue around the world and the potential influence on vectorial capacity needs to be studied. Here we selected a permethrin resistant (p-s) Aedes aegypti population from a wild Florida population and confirmed the resistance ratio to its parental population. We used allele-specific PCR genotyping of the V1016I and F1534C sites in the sodium channel gene to map mutations responsible for the resistance. Two important factors, survival rate and vector competence, that impact vectorial capacity were checked. Results indicated the p-s population had 20 times more resistance to permethrin based on LD50 compared to the parental population. In the genotyping study, the p-s population had more homozygous mutations in both mutant sites of the sodium channel gene. The p-s adults survived longer and had a higher dissemination rate for dengue virus than the parental population. These results suggest that highly permethrin resistant Aedes aegypti populations might affect the vectorial capacity, moreover, resistance increased the survival time and vector competence, which should be of concern in areas where permethrin is applied.


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