scholarly journals Field evaluation of WALS truck-mounted A1 super duty mist sprayer® with VectoBac® WDG against Aedes aegypti (Diptera:Culicidae) populations in Manatee County, Florida

2022 ◽  
Vol 4 (2) ◽  
Author(s):  
Katie Katie Williams ◽  
Samantha Ramirez ◽  
Christopher R. Lesser

AbstractAedes aegypti, the Dengue and Zika vector, is a domestic mosquito that is difficult to control. The challenge lies in the mosquito’s preference to lay its eggs in cryptic habitats such as fence post openings, buckets and bird baths, cups. Additionally, current methods of control are labor-intensive. We employed the WALS strategy to evaluate the operational efficacy of applying VectoBac WDG using a truck-mounted mister to control local populations of Ae. aegypti in urban settings with difficult-to-reach larval mosquito habitats. Our study was conducted in Cortez (Manatee County), Florida, USA (27° 27’ N, 82° 40’ W). We selected two study sites, one untreated control (21.9 ha) and one treatment site (23.1 ha) where historical data have shown high populations of Ae. aegypti based on weekly ovitrap surveillance. Weekly BGs and ovitraps (10–15 traps/site) were deployed to monitor adult population dynamics. A total of 50 bioassay jars were placed in the field each afternoon of the Bti application (8 application events) at fixed locations to collect droplets and gauge efficacy. We found significant reduction in female adults (P = 0.0002) and landing rate counts (P = 0.0058) as a result of treatment. Larval bioassays during the eight applications confirmed Bti deposit in a variety of coverage types regardless of placement in the yards. WALS applications with a truck-mounted mister can be effective at reducing disease carrying mosquito populations in residential areas and can be implemented in an integrated vector management program.

2018 ◽  
Vol 34 (1) ◽  
pp. 58-62 ◽  
Author(s):  
Seth C. Britch ◽  
Kenneth J. Linthicum ◽  
Robert L. Aldridge ◽  
Frances V. Golden ◽  
Arissara Pongsiri ◽  
...  

ABSTRACT We investigated the efficacy of a liquid larvicide, Natular 2EC® (spinosad), applied with ultra-low volume sprayer as a residual application during the dry season in southeastern Thailand against 4 medically important species—Aedes aegypti, Ae. albopictus, Anopheles dirus, and An. minimus. We found that this larvicide could be applied as a residual to dry areas known to collect water and potentially still be effective after rains or irrigation, which could increase the flexibility and efficiency of an integrated vector management program targeting these species. This investigation also demonstrated, for the 1st time, efficacy of spinosad against An. minimus and An. dirus.


2018 ◽  
Vol 34 (1) ◽  
pp. 53-57 ◽  
Author(s):  
Robert L. Aldridge ◽  
Frances V. Golden ◽  
Seth C. Britch ◽  
Jessika Blersch ◽  
Kenneth J. Linthicum

ABSTRACT Preemptive treatment of dry habitats with an ultra-low volume (ULV) residual larvicide may be effective in an integrated vector management program to control populations of container-inhabiting Aedes mosquitoes, key vectors of Zika, dengue, and chikungunya viruses. We exposed dry, artificial containers placed in exposed and protected locations to Natular 2EC (spinosad) larvicide applied with a truck-mounted ULV sprayer in a simulated urban setting in North Florida, and later introduced water and Ae. aegypti or Ae. albopictus larvae to conduct bioassays. Up to 50% mortality was observed in bioassays, indicating further analysis of spinosad as a residual treatment application.


2021 ◽  
Vol 68 (1) ◽  
pp. 63-69
Author(s):  
Vindhya S. Aryaprema

Sterile insect technique (SIT) using irradiated mosquitoes is an effective control method capable of being assimilated into integrated vector management (IVM) programs. Chemical control of mosquitoes using ultra-low volume (ULV) spray applications of pyrethroid and organophosphate insecticides is already an essential component of IVM programs. Prior to their release in nature, irradiation of mosquitoes for SIT use can significantly impact the mosquito’s biology, specifically its host-seeking and feeding behavior. Little is known about how radiation exposure might impact a mosquito’s susceptibility to pyrethroid insecticides. The present study was carried out to evaluate the influence of Aqualuer ® 20-20 ULV applications on irradiated Aedes aegypti. Caged mosquito trials indicated that both male and female irradiated Ae. aegypti were as susceptible as their non-irradiated counterparts of the same population to Aqualuer 20-20 ULV application, with the highest mean percent mortalities achieved at the first 24h post-treatment period at both 30.5 m and 61 m downwind of the spray application path.


ENTOMON ◽  
2018 ◽  
Vol 43 (4) ◽  
pp. 223-230
Author(s):  
S. Sunil Kumar ◽  
D.A. Evans ◽  
K. Muthulakshmi ◽  
T. DilipKumar ◽  
R. Heera Pillai ◽  
...  

Mosquito index study of three ecologically different ecozones of the Thiruvananthapuram district, Kerala showed sharp difference on the proportionate distribution of Aedes aegypti and Aedes albopictus. Human dengue viremia (HDV) was very high in those ecozones where A.aegypti density was high and HDV was low where A.albopictus was high. In a coastal zone of Thiruvananthapuram city, A. aegypti was the most abundant vector and in a hilly, arid suburban zone, A.albopictus was the abundant vector. In the urban zone both species of mosquitoes showed equal distribution. Study on the circulating serotypes in the serum of HDV by Single step single tube Multiplex PCR showed all the four serotypes viz DENV1, DENV2, DENV3 and DENV4 in patients of Thiruvananthapuram city, which indicated the possibility of Dengue Shock Syndrome, unless there is efficient vector management. Among the four dengue serotypes, Type 1 was the most abundant virus. Abundance of microhabitats in Thiruvananthapuram city, which support A. aegypti may be the reason for high prevalence of dengue fever in the urban zone.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Emmanuel Mbuba ◽  
Olukayode G. Odufuwa ◽  
Frank C. Tenywa ◽  
Rose Philipo ◽  
Mgeni M. Tambwe ◽  
...  

Abstract Background N,N-Diethyl-3-methylbenzamide (DEET) topical mosquito repellents are effective personal protection tools. However, DEET-based repellents tend to have low consumer acceptability because they are cosmetically unappealing. More attractive formulations are needed to encourage regular user compliance. This study evaluated the protective efficacy and protection duration of a new topical repellent ointment containing 15% DEET, MAÏA® compared to 20% DEET in ethanol using malaria and dengue mosquito vectors in Bagamoyo Tanzania. Methods Fully balanced 3 × 3 Latin square design studies were conducted in large semi-field chambers using laboratory strains of Anopheles gambiae sensu stricto, Anopheles arabiensis and Aedes aegypti. Human volunteers applied either MAÏA® ointment, 20% DEET or ethanol to their lower limbs 6 h before the start of tests. Approximately 100 mosquitoes per strain per replicate were released inside each chamber, with 25 mosquitoes released at regular intervals during the collection period to maintain adequate biting pressure throughout the test. Volunteers recaptured mosquitoes landing on their lower limbs for 6 h over a period of 6 to 12-h post-application of repellents. Data analysis was conducted using mixed-effects logistic regression. Results The protective efficacy of MAÏA® and 20% DEET was not statistically different for each of the mosquito strains: 95.9% vs. 97.4% against An. gambiae (OR = 1.53 [95% CI 0.93–2.51] p = 0.091); 96.8% vs 97.2% against An. arabiensis (OR = 1.08 [95% CI 0.66–1.77] p = 0.757); 93.1% vs 94.6% against Ae. aegypti (OR = 0.76 [95% CI 0.20–2.80] p = 0.675). Average complete protection time (CPT) in minutes of MAÏA® and that of DEET was similar for each of the mosquito strains: 571.6 min (95% CI 558.3–584.8) vs 575.0 min (95% CI 562.1–587.9) against An. gambiae; 585.6 min (95% CI 571.4–599.8) vs 580.9 min (95% CI 571.1–590.7) against An. arabiensis; 444.1 min (95% CI 401.8–486.5) vs 436.9 min (95% CI 405.2–468.5) against Ae. aegypti. Conclusions MAÏA® repellent ointment provides complete protection for 9 h against both An. gambiae and An. arabiensis, and 7 h against Ae. aegypti similar to 20% DEET (in ethanol). MAÏA® repellent ointment can be recommended as a tool for prevention against outdoor biting mosquitoes in tropical locations where the majority of the people spend an ample time outdoor before going to bed.


2017 ◽  
Vol 33 (2) ◽  
pp. 116-127 ◽  
Author(s):  
A. Ponlawat ◽  
J. F. Harwood ◽  
J. L. Putnam ◽  
C. Nitatsukprasert ◽  
A. Pongsiri ◽  
...  

2021 ◽  
Vol 37 (4) ◽  
pp. 242-249
Author(s):  
Eva A. Buckner ◽  
Katie F. Williams ◽  
Samantha Ramirez ◽  
Constance Darrisaw ◽  
Juliana M. Carrillo ◽  
...  

ABSTRACT Aedes aegypti is the predominant vector of dengue, chikungunya, and Zika viruses. This mosquito is difficult to control with conventional methods due to its container-inhabiting behavior and resistance to insecticides. Autodissemination of pyriproxyfen (PPF), a potent larvicide, has shown promise as an additional tool to control Aedes species in small-scale field trials. However, few large-scale field evaluations have been conducted. We undertook a 6-month-long large-scale field study to compare the effectiveness and operational feasibility of using In2Care Mosquito Traps (In2Care Traps, commercially available Aedes traps with PPF and Beauveria bassiana) compared to an integrated vector management (IVM) strategy consisting of source reduction, larviciding, and adulticiding for controlling Ae. aegypti eggs, larvae, and adults. We found that while the difference between treatments was only statistically significant for eggs and larvae (P < 0.05 for eggs and larvae and P > 0.05 for adults), the use of In2Care Traps alone resulted in 60%, 57%, and 57% fewer eggs, larvae, and adults, respectively, collected from that site compared to the IVM site. However, In2Care Trap deployment and maintenance were more time consuming and labor intensive than the IVM strategy. Thus, using In2Care Traps alone as a control method for large areas (e.g., >20 ha) may be less practical for control programs with the capacity to conduct ground and aerial larviciding and adulticiding. Based on our study results, we conclude that In2Care Traps are effective at suppressing Ae. aegypti and have the most potential for use in areas without sophisticated control programs and within IVM programs to target hotspots with high population levels and/or risk of Aedes-borne pathogen transmission.


CJEM ◽  
2017 ◽  
Vol 19 (S1) ◽  
pp. S97 ◽  
Author(s):  
L. Gaudet ◽  
L. Eliyahu ◽  
J. Lowes ◽  
J. Beach ◽  
M. Mrazik ◽  
...  

Introduction: Patients with mild traumatic brain injury (mTBI) often present to the emergency department (ED). Incorrect diagnosis may delay appropriate treatment and recommendations for these patients, prolonging recovery. Notable proportions of missed mTBI diagnosis have been documented in children and athletes, while diagnosis of mTBI has not been examined in the general adult population. Methods: A prospective cohort study was conducted in one academic (site 1) and two non-academic (sites 2 and 3) EDs in Edmonton, Canada. On-site research assistants enrolled adult (>17 years) patients presenting within 72 hours of the injury event with clinical signs of mTBI and Glasgow comma scale score ≥13. Patient demographics, injury characteristics, and ED flow information were collected by chart review. Physician-administered questionnaires and patient interviews documented the recommendations given by emergency physicians at discharge. Bi-variable comparisons are reported using Pearson’s chi-square tests, Student’s t-tests or Mann-Whitney tests, as appropriate. Multivariate analyses were performed using logistic regression methods. Results: Overall, 130/250 enrolled patients were female, and the median age was 35. Proportions of successfully diagnosed mTBI varied significantly across study sites (Site 1: 89%; Site 2: 73%, Site 3: 53%; p>0.001). Patients without a diagnosis were less likely to receive a recommendation to follow-up with their family physician (OR=0.08; 95% CI: 0.03, 0.21) or advice about return to work (OR=0.17; 95% CI: 0.08, 0.04) or physical activity (OR=0.08; 95% CI: 0.04, 0.17). Patients with missed diagnoses had longer ED stays (median=5.0 hours; IQR: 3.8, 7.0) compared with diagnosed mTBI patients (median=3.9 hours; IQR: 3.0, 5.3). In the adjusted model, patients presenting to non-academic centers had reduced likelihood of mTBI diagnosis (Site 2: OR=0.21; 95% CI: 0.08, 0.58; Site 3: OR=0.07; 95% CI: 0.02, 0.24). Conclusion: The diagnostic accuracy of physicians assessing patients presenting with symptoms of mTBIs to these three EDs is suboptimal. The rates of missed diagnosis vary among EDs and were associated with length of ED stay. Closer examination of institutional factors, including diagnosis processes and personnel factors such as physician training, is needed to identify effective strategies to heighten the awareness of mTBI presentations.


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