scholarly journals Integrated control of Aedes albopictus in Southwest Germany supported by the Sterile Insect Technique

2022 ◽  
Vol 15 (1) ◽  
Author(s):  
Norbert Becker ◽  
Sophie Min Langentepe-Kong ◽  
Artin Tokatlian Rodriguez ◽  
Thin Thin Oo ◽  
Dirk Reichle ◽  
...  
Keyword(s):  
Aedes Albopictus ◽  
Sterile Insect Technique ◽  
Large Scale ◽  
Integrated Control ◽  
Control Program ◽  
Control Area ◽  
West Germany ◽  
Mosquito Vector ◽  
Breeding Sites ◽  
South West

Abstract Background The invasive species Aedes albopictus, commonly known as the Asian tiger mosquito, has undergone extreme range expansion by means of steady introductions as blind passengers in vehicles traveling from the Mediterranean to south-west Germany. The more than 25 established populations in the State of Baden-Württemberg, Palatine and Hesse (south-west Germany) have become a major nuisance and public health threat. Aedes albopictus deserves special attention as a vector of arboviruses, including dengue, chikungunya and Zika viruses. In Germany, Ae. albopictus control programs are implemented by local communities under the auspices of health departments and regulatory offices. Methods The control strategy comprised three pillars: (i) community participation (CP) based on the elimination of breeding sites or improved environmental sanitation, using fizzy tablets based on Bacillus thuringiensis israelensis (fizzy Bti tablets; Culinex® Tab plus); (ii) door-to-door (DtD) control by trained staff through the application of high doses of a water-dispersible Bti granular formulation (Vectobac® WG) aimed at achieving a long-lasting killing effect; and (iii) implementation of the sterile insect technique (SIT) to eliminate remaining Ae. albopictus populations. Prior to initiating large-scale city-wide treatments on a routine basis, the efficacy of the three elements was evaluated in laboratory and semi-field trials. Special emphasis was given to the mass release of sterile Ae. albopictus males. Results More than 60% of the local residents actively participated in the first pillar (CP) of the large-scale control program. The most effective element of the program was found to be the DtD intervention, including the application of Vectobac® WG (3000 ITU/mg) to potential breeding sites (10 g per rainwater container, maximum of 200 l = maximum of approx. 150,000 ITU/l, and 2.5 g per container < 50 l) with a persistence of at least 3 weeks. In Ludwigshafen, larval source management resulted in a Container Index for Ae. albopictus of < 1% in 2020 compared to 10.9% in 2019. The mean number of Aedes eggs per ovitrap per 2 weeks was 4.4 in Ludwigshafen, 18.2 in Metzgergrün (Freiburg) (SIT area) and 22.4 in the control area in Gartenstadt (Freiburg). The strong reduction of the Ae. albopictus population by Bti application was followed by weekly releases of 1013 (Ludwigshafen) and 2320 (Freiburg) sterile Ae. albopictus males per hectare from May until October, resulting in a high percentage of sterile eggs. In the trial areas of Ludwigshafen and Frieburg, egg sterility reached 84.7 ± 12.5% and 62.7 ± 25.8%, respectively; in comparison, the natural sterility in the control area was 14.6 ± 7.3%. The field results were in line with data obtained in cage tests under laboratory conditions where sterility rates were 87.5 ± 9.2% after wild females mated with sterile males; in comparison, the sterility of eggs laid by females mated with unirradiated males was only 3.3 ± 2.8%. The overall egg sterility of about 84% in Ludwigshafen indicates that our goal to almost eradicate the Ae. albopictus population could be achieved. The time for inspection and treatment of a single property ranged from 19 to 26 min depending on the experience of the team and costs 6–8 euros per property. Conclusions It is shown that an integrated control program based on a strict monitoring scheme can be most effective when it comprises three components, namely CP, DtD intervention that includes long-lasting Bti-larviciding to strongly reduce Ae. albopictus populations and SIT to reduce the remaining Ae. albopictus population to a minimum or even to eradicate it. The combined use of Bti and SIT is the most effective and selective tool against Ae. albopictus, one of the most dangerous mosquito vector species. Graphical Abstract

scholarly journals Integrated Control of Aedes Albopictus (Diptera: Culicidae) in Southwest Germany supported by the Sterile Insect Technique

2021 ◽  
Author(s):  
Norbert Becker ◽  
Sophie Min Langentepe-Kong ◽  
Artin Tokatlian Rodriguez ◽  
Thin Thin Oo ◽  
Dirk Reichle ◽  
...  
Keyword(s):  
Community Participation ◽  
Aedes Albopictus ◽  
Sterile Insect Technique ◽  
Large Scale ◽  
Integrated Control ◽  
Control Program ◽  
Control Area ◽  
West Germany ◽  
Breeding Sites ◽  
South West

Abstract BackgroundThe invasive species Aedes albopictus, the Asian tiger mosquito, has undergone an extreme expansion by steady introductions as blind passengers in vehicles from the Mediterranean to South-West Germany. The more than 15 established populations in the State of Baden-Württemberg and Palatine (South-West Germany) have become a major nuisance and public health threat. Aedes albopictus deserves special attention as vector of arboviruses like dengue, chikungunya or Zika virus. In Germany, control of Ae. albopictus is implemented under the auspice of health departments and regulatory offices. MethodsThe control strategy comprised three components or pillars: a) community participation (CP) based on the elimination or sanitation of breeding sites with the use of fizzy Bti-tablets (Culinex Tab plus); b) Door-to-Door (DtD) control by trained staff applying high doses of a Bti-water-dispersible granular formulation (Vectobac WG) aimed for a long-lasting killing effect; and c) the Sterile Insect Technique (SIT) to eliminate remaining Ae. albopictus populations. Prior to large scale routine city-wide treatments, the efficacy of the three elements was evaluated in laboratory and semi-field trials. Special emphasis was given to the mass release of Ae. albopictus sterile males.ResultsMore than 60% of the local residents joined the Community Participation within the large-scale control program. It was shown that the most effective element was the DtD intervention including the application of Vectobac WG (2700 ITU/mg after radiation with 25 kGy) to potential breeding sites (10 g/rainwater container, max. 200L ≙ 13,500ITU/L and 2.5g/container <50L) with a persistence of at least about three weeks. The average time required for the inspection and treatment per property was 27 minutes. In Ludwigshafen the larval source management resulted in a container index for Ae. albopictus below 1% in 2020 compared to 10.9% in 2019. The mean number of Aedes eggs/ovitrap were 4.3 in Ludwigshafen and 18.23 in Freiburg-Metzgergrün (SIT areas); while 22.4 in Freiburg-Gartenstadt (Control area). After the strong reduction of the Aedes population by Bti-application, the weekly release of 1,013 (Ludwigshafen) and 2,320 (Freiburg) sterile Ae. albopictus males/ha from May until October resulted in a high percentage of sterile eggs. In the trial area of Ludwigshafen the sterility of eggs reached 82.61% (mean: 60.52%; SD: 42.88%) and in Freiburg 62.68% (SD 28.21%). The natural sterility in the control area was 16.93±13.5%. The field results were in line with data obtained in cage tests under laboratory conditions where wild females mated with sterile males showed sterility rates of 87.53±9.15%. The sterility of eggs laid by females mated with unirradiated males was only 3.3±2.8%. The overall sterility of about 83% in Ludwigshafen indicates that our goal to almost eradicate the Ae. albopictus population could be achieved. ConclusionsIt is shown that an integrated control program based on a strict monitoring scheme is most effective when it comprises three components, namely a) community participation, b) DtD intervention including long-lasting Bti-larviciding to strongly reduce Ae. albopictus populations and c) the release of sterile males to reduce the remaining Ae. albopictus population to a minimum or even to eradicate it. The combination of the use of Bti with SIT are most effective and selective tools against Ae. albopictus, one of the most dangerous mosquito vector species.

scholarly journals Model-Like Implementation of Integrated Control Strategies Targeting Aedes Albopictus (Diptera: Culicidae) In Southwest Germany With Special Consideration of the Sterile Insect Technique

2021 ◽  
Author(s):  
Norbert Becker ◽  
Sophie Langentepe-Kong ◽  
Artin Tokatlian ◽  
Thin Thin Oo ◽  
Dirk Reichle ◽  
...  
Keyword(s):  
Aedes Albopictus ◽  
Control Strategy ◽  
Sterile Insect Technique ◽  
Integrated Control ◽  
West Germany ◽  
Asian Tiger Mosquito ◽  
Breeding Sites ◽  
South West ◽  
Asian Tiger ◽  
The Mean

Abstract BackgroundIn recent years the invasive species Aedes albopictus, known as the Asian tiger mosquito, has undergone an extreme expansion by steady introductions as blind passengers in vehicles from the Mediterranean to South-West Germany. Nowadays, more than 15 established populations are known in the State of Baden-Württemberg and Palatine (South-West Germany) which locally constitute a significant nuisance and public health threat. Therefore, the species deserves special attention as vector of several arboviruses like dengue, Chikungunya or Zika virus. As a consequence, immediate surveillance and control activities against Aedes albopictus have been implemented in the infested areas under the auspice of health departments and regulatory offices. MethodsThe control strategy comprises 3 columns: a) community participation (CP) based on detailed information for the elimination and sanitation of breeding sites as well as the use of fizzy Bti-tablets containing the pro-toxins of Bacillus thuringiensis israelensis (Bti); b) Door-to-Door (DtD) activities by trained staff including the application of Bti (Vectobac WG) at high dosages to achieve a sustained killing effect of the mosquito larvae; and c) the Sterile Insect Technique (SIT) to almost wipe out or eliminate the remaining Aedes albopictus population after intensive Bti-applications. In the laboratory and in semi-field tests, the different elements of the control strategy are evaluated and the efficacy of the integrated control strategy is assessed in routine treatments in the cities of Ludwigshafen (Palatine) and Freiburg (Baden-Württemberg) with special emphasis on the release of sterile Aedes/males. ResultsFollowing our information campaigns, more than 60% of the residents were practicing CP focusing on environmental sanitation and the use of fizzy Bti tablets. Although CP is an essential element of the integrated control strategy, it was shown that the strongest asset in our programme was the DtD activity and the application of a water suspension of Vectobac WG (2700 ITU/mg) to all potential breeding sites at dosages of 10g/rainwater container and 2.5g/smaller container which provided an effect for more than a month. The mean time for the inspection and treatment of a property was 27 minutes. As a result of the larval source management, the container index for Aedes albopictus achieved no more than 0.5% in Ludwigshafen. The mean number of Aedes eggs/ovitrap in Ludwigshafen was 4,3 and in Freiburg -Metzgergrün (SIT area) 18.23 and Freiburg-Gartenstadt-Freiburg (Control area) 22,4 eggs/trap. After the strong reduction of the Aedes population by Bti-application, the weekly release of 1013 (Ludwigshafen) and 2320 (Freiburg) sterile Aedes albopictus males/ha from May until October resulted in an overall sterility by egg counts 82.61% ( (Ø60.52±42.88%) in Ludwigshafen and 62.68±28.21% in Freiburg compared to a natural sterility of 16.93±13.5% in the SIT untreated area. The field results are proven by the data achieved in cage tests in the laboratory. The mating of wild females with sterile males showed sterility rates of 87.53±9.15% whereas the sterility of eggs laid by females mated with unirradiated males was only 3.3±2.8%. The most effective ratio of wild to sterile males is 1:5. The overall sterility of about 83% in Ludwigshafen indicates that our goal to almost eradicate the Aedes albopictus population could be achieved. The hydrogen-peroxide bleaching technique allowed a quick assessment of embryogenesis. ConclusionsIn this study, we clearly prove that an integrated control program based on a strict monitoring scheme is most effective when it comprises three columns, namely a) community participation, b) DtD activities including long-lasting Bti-larviciding of all possible breeding sites to strongly reduce the wild Aedes albopictus population as a basis for the successful application of SIT, and c) SIT to almost wipe out the Aedes albopictus population. The combination of Bti and SIT guarantees that two of the most selective, save and effective tools are employed against one of the most dangerous mosquito vector species Aedes albopictus, the Asian tiger mosquito.

scholarly journals Influence of strategic points in the dispersion of Aedes aegypti in infested areas

2019 ◽  
Vol 53 ◽  
pp. 29 ◽  
Author(s):  
Gerson Laurindo Barbosa ◽  
Mariana De Oliveira Lage ◽  
Valmir Roberto Andrade ◽  
Antônio Henrique Alves Gomes ◽  
Jose Alberto Quintanilha ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Spatial Statistics ◽  
Random Distribution ◽  
Control Program ◽  
Control Area ◽  
Point Of View ◽  
Economic Point ◽  
Breeding Sites ◽  
Vector Control Program

OBJECTIVE: To evaluate whether sites with large amount of potential breeding sites for immature forms of Aedes aegypti, called strategic points, influence in the active vector’s dispersion into properties in their surroundings. METHODS: We selected four areas in the municipality of Campinas, three of them with strategic points classified as high, moderate, and low risk according to infestation and a control area, without strategic points. Between October 2015 and September 2016, we monthly installed oviposition traps and evaluated the infestation by Ae. aegypti in all properties of each selected area. To verify if there was vector dispersion from each strategic point, based on its location, we investigated the formation of clusters with excess of eggs or larvae or pupae containers, using the Gi spatial statistics. RESULTS: The amount of eggs collected in the ovitraps and the number of positive containers for Ae. aegypti did not show clusters of high values concerning its distance from the strategic point. Both presented random distribution not spatially associated with the positioning of strategic points in the area. CONCLUSIONS: Strategic points are not confirmed as responsible for the vector’s dispersion for properties in their surroundings. We highlight the importance of reviewing the current strategy of the vector control program in Brazil, seeking a balance from the technical, operational, and economic point of view, without disregarding the role of strategic points as major producers of mosquitoes and their importance in the dissemination of arboviruses in periods of transmission.

scholarly journals Runoff reaction from extreme rainfall events on natural hillslopes: A data set from 132 large scale sprinkling experiments in south-west Germany

2019 ◽  
Author(s):  
Fabian Ries ◽  
Lara Kirn ◽  
Markus Weiler
Keyword(s):  
Large Scale ◽  
Subsurface Flow ◽  
West Germany ◽  
Runoff Generation ◽  
Large Variability ◽  
Maximum Rainfall ◽  
Rainfall Events ◽  
Extreme Precipitation Events ◽  
South West ◽  
Precipitation Events

Abstract. Pluvial or flash floods generated by heavy precipitation events cause high economic damages and loss of life worldwide. As discharge observations from such extreme occurrences are rare especially on the scale of small catchments or even hillslopes, data from artificial sprinkling experiments offer valuable information on runoff generation processes, overland and subsurface flow rates and response times. We conducted 132 large-scale sprinkling experiments on natural hillslopes at 23 sites with different soil types and geology on pastures and arable lands within the federal state of Baden-Württemberg in south-west Germany. The experiments were realized between 2016 and 2017. Simulated rainfall events of varying durations were based on a) the site-specific 100-year return periods of rainfall with different durations and b) the maximum rainfall intensity observed locally. The 100 m2 experimental area was divided into three individual plots and overland and subsurface flow, soil moisture and water level dynamics in the temporarily saturated soil zone were measured at 1-minute resolution. Furthermore, soil characteristics were described in detail for each site. The data was carefully processed and corrected for measurement errors and combined to a consistent and easy to use database. The experiments revealed a large variability of possible runoff responses to similar rainfall characteristics. In general, agricultural fields produced more overland flow than grassland. The latter generated hardly any runoff during the first simulated 100-year event on initially dry soils. The dataset provides valuable information on runoff generation variability from natural hillslopes and may be used for the development and evaluation of hydrological models, especially those considering physical processes governing runoff generation during extreme precipitation events. The dataset presented in this paper is freely available from the FreiDok plus data repository (https://doi.org/10.6094/UNIFR/149650, Ries et al., 2019).

scholarly journals A Biosecurity Response to Aedes albopictus (Diptera: Culicidae) in Auckland, New Zealand

2010 ◽  
Vol 47 (4) ◽  
pp. 600-609 ◽  
Author(s):  
Peter Holder ◽  
Sherly George ◽  
Mark Disbury ◽  
Monica Singe ◽  
John M. Kean ◽  
...  
Keyword(s):  
New Zealand ◽  
Aedes Albopictus ◽  
Large Scale ◽  
Light Trapping ◽  
Control Program ◽  
Larval Habitat ◽  
Habitat Modification ◽  
Surveillance Program ◽  
Founding Population ◽  
Trace Back

Abstract A biosecurity response was triggered by the detection of Aedes albopictus (Skuse) (Diptera: Culicidae) at the Port of Auckland, New Zealand. Ae. albopictus does not occur in New Zealand and is the most significant mosquito threat to this country. The possibility that a founding population had established, resulted in a large-scale biosecurity surveillance and control program. The response was initiated in early March 2007 and completed by mid-May 2007. No further exotic mosquitoes were detected. The response surveillance program consisted of larval habitat surveys and high density ovi- and light trapping. It was coordinated with a habitat modification and S-methoprene treatment control program. The response policies were guided by analysis of surveillance and quality assurance data, population modeling, and trace-back activities. Mosquito habitat and activity close to port were both more abundant than expected, particularly in storm water drain sumps. Sumps are difficult to treat, and during the response some modification was required to the surveillance program and the control regime. We were assured of the absence or eradication of any Ae. albopictus population, as a result of nil detection from surveillance, backed up by four overlapping rounds of insecticide treatment of habitat. This work highlights the importance of port surveillance and may serve as a guide for responses for future urban mosquito incursions.

scholarly journals Successful suppression of a field population of Ae. aegypti mosquitoes using a novel biological vector control strategy is associated with significantly lower incidence of dengue

2019 ◽  
Author(s):  
Lisiane C Poncio ◽  
Filipe A dos Anjos ◽  
Deborah A de Oliveira ◽  
Débora Rebechi ◽  
Rodrigo N de Oliveira ◽  
...  
Keyword(s):  
Vector Control ◽  
Lower Incidence ◽  
Large Scale ◽  
Control Area ◽  
Environmentally Benign ◽  
Mosquito Population ◽  
Mosquito Vector ◽  
Sterile Male ◽  
Treated Area ◽  
Male Mosquitoes

AbstractBackgroundDespite extensive efforts to prevent recurrent Aedes-borne arbovirus epidemics, there is a steady rise in their global incidence. Vaccines/treatments show very limited efficacy and together with the emergence of mosquito resistance to insecticides, it has become urgent to develop alternative solutions for efficient, sustainable and environmentally benign mosquito vector control. Here we present a new Sterile Insect Technology (SIT)-based program that uses large-scale releases of sterile male mosquitoes produced by a highly effective, safe and environmentally benign method.Methods and findingsTo test the efficacy of this approach, a field trial was conducted in a Brazilian city (Jacarezinho), which presented a history of 3 epidemics of dengue in the past decade. Sterile male mosquitoes were produced from a locally acquired Aedes aegypti colony, and releases were carried out on a weekly basis for seven months in a predefined area. This treated area was matched to a control area, in terms of size, layout, historic mosquito infestation index, socioeconomic patterns and comparable prevalence of dengue cases in past outbreaks. Releases of sterile male mosquitoes resulted in up to 91.4% reduction of live progeny of field Ae. aegypti mosquitoes recorded over time. The reduction in the mosquito population was corroborated by the standard monitoring system (LIRAa index) as determined by the local municipality, which found that our treated neighborhoods were almost free of Ae. aegypti mosquitoes after 5 months of release, whereas neighborhoods adjacent to the treated area and the control neighborhoods were highly infested. Importantly, when a dengue outbreak started in Jacarezinho in March 2019, the effective mosquito population suppression was shown to be associated with a far lower incidence of dengue in the treated area (16 cases corresponding to 264 cases per 100,000 inhabitants) almost 16 times lower than the dengue incidence in the control area (198 cases corresponding to 4,360 dengue cases per 100,000 inhabitants).ConclusionsOur data present the first demonstration that a SIT-based intervention has the potential to prevent the spread of dengue, opening exciting new opportunities for preventing mosquito-borne disease.

scholarly journals Two invasive mosquito species, Aedes albopictus and Aedes japonicus japonicus, trapped in south-west Germany, July to August 2011

2012 ◽  
Vol 17 (4) ◽  
Author(s):  
D Werner ◽  
M Kronefeld ◽  
F Schaffner ◽  
H Kampen
Keyword(s):  
Aedes Albopictus ◽  
Mosquito Species ◽  
West Germany ◽  
Aedes Japonicus ◽  
Aedes Japonicus Japonicus ◽  
South West ◽  
Invasive Mosquito ◽  
Rhine Valley ◽  
First Time ◽  
Upper Rhine

Adult females of two invasive species, Aedes albopictus and Aedes japonicus japonicus, were collected for the first time in July and August 2011 in Germany. Previously, only immature stages of these species had been found in the country. Repeated detection of these species reveals the Upper Rhine Valley in south-west Germany to be a particularly sensitive region for the introduction and establishment of exotic mosquito species that needs careful observation.

A Simple PCR Assay for Discrimination of Dengue Vectors from Nsukka LGA, Nigeria

2020 ◽  
Vol 10 (1) ◽  
pp. 67-77
Author(s):  
Amos Watentena ◽  
Ikem Chris Okoye ◽  
Ikechukwu Eugene Onah ◽  
Onwude Cosmas Ogbonnaya ◽  
Emmanuel Ogudu
Keyword(s):  
Aedes Aegypti ◽  
Aedes Albopictus ◽  
Mosquito Species ◽  
Public Health Problem ◽  
Major Public Health Problem ◽  
Mosquito Vector ◽  
Aedes Mosquitoes ◽  
Allele Specific ◽  
Arboviral Diseases ◽  
Dengue Vectors

Mosquitoes of Aedes species are vectors of several arboviral diseases which continue to be a major public health problem in Nigeria. This study among other things, morphologically identified Aedes mosquitoes collected from Nsukka LGA and used an allele specific PCR amplification for discrimination of dengue vectors. Larval sampling, BG-sentinel traps and modified human landing catches were used for mosquito sampling in two selected autonomous communities of Nsukka LGA (Nsukka and Obimo). A total of 124 Aedes mosquitoes consisting of five (5) different species were collected from April to June, 2019 in a cross-sectional study that covered 126 households, under 76 distinct geographical coordinates. Larvae was mainly collected from plastic containers 73% (n=224), metallic containers 14% (n=43), earthen pots 9% (n=29) and used car tyres 3% (n=9), reared to adult stage 69.35% (n=86), and all mosquitoes were identified using standard morphological keys. Five (5) Aedes mosquito species were captured; Aedes aegypti 83(66.94%), Aedes albopictus 33(26.61%), Aedes simpsoni (4.48%), Aedes luteocephalus (≤1%) and Aedes vittatus (≤1%). Nsukka autonomous community had higher species diversity than Obimo. Allele specific amplification confirmed dengue vectors, Aedes aegypti and Aedes albopictus species on a 2% agarose gel. Since the most recent re-emergence of arboviral diseases is closely associated with Aedes species, findings of this study, therefore, give further evidence about the presence of potential arboviral vectors in Nigeria and describe the role of a simple PCR in discriminating some. Further entomological studies should integrate PCR assays in mosquito vector surveillance.

In-situ U-Pb dating of Ries Crater lacustrine carbonates (Miocene, South-West Germany): Implications for continental carbonate chronostratigraphy

2021 ◽  
Vol 568 ◽  
pp. 117011
Author(s):  
Damaris Montano ◽  
Marta Gasparrini ◽  
Axel Gerdes ◽  
Giovanna Della Porta ◽  
Richard Albert
Keyword(s):  
West Germany ◽  
South West ◽  
Lacustrine Carbonates
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