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Rapid Elimination of Aedes aegypti and Culex quinquefasciatus Mosquitoes from Puerco Island, Palawan, Philippines with Odor-Baited Traps

Biogents traps have previously been shown to be a suitable, pesticide-free alternative for mosquito control. High-density trapping is an environmentally friendly, pesticide-free, cost-effective, and mosquito-specific approach to control or eliminate mosquito nuisance biting and disease risk for people living in (small) islands in the tropics.

In this study, Biogents traps were used on a small island in the Philippines. Using BG-Mosquitaire CO2 traps resulted in a fast decline in populations of two mosquito species (Ae. aegypti and Cx. quinquefasciatus). Within five months, the mosquitoes were eliminated. This is the second time that odor-baited traps have succeeded in eliminating mosquitoes from a small tropical island.

• Mass trapping treatment: 10 Biogents BG-Mosquitaire CO2 traps per hectare
• Larval source management (limited in scope): breeding sites for mosquitoes were inspected and removed where possible
• Occasionally, tablets containing the larvicide Spinosad (Naturäl™) were used in water tanks or other water collections that could not be removed

Figure 1. Location of Puerco Island, Palawan, Philippines. A) Map of the Philippines, showing the location of Palawan. B) Satellite image of Puerco Island.

Figure 2. Average number of mosquitoes caught per day per monitoring trap between 13 July and 25 March 2023 on Puerco Island. Blue bars show rainfall (mm) per day.

The mosquito density decreased very fast. The number of collected mosquitoes was constantly zero or close to zero about three months after the control measures started. Heavy rainfall did not lead to an increase or re-appearance of mosquitoes.

• Read more: Knols et al. 2023 – Download publication

Mass Trapping with Biogents traps and Larval Source Management for Mosquito Elimination on Small Maldivian Islands

This was the case on a Maldivian island of 41 hectares: the location of Soneva Fushi, a high-end luxury villa resort. Over two decades, insecticides were sprayed almost daily by a pest control company to reduce mosquito nuisance caused by Asian tiger mosquitoes (Aedes albopictus) and southern house mosquitoes (Culex quinquefasciatus). Soneva Fushi ended the contract with the pest control company, as the mosquitoes became resistant to the used insecticides (permethrin and deltamethrin).

The eco-friendly mosquito control approach based on the use of Biogents BG-Mosquitaire CO2 traps, Biogents BG-GAT traps, and removal of breeding sites resulted in the near elimination of the mosquito population. Additionally, within 1.5 years without insecticide spraying, several beneficial insect species (bumble bees, carpenter bees, dragonflies, butterflies) that had disappeared from the island due to extensive insecticide use, have returned. Furthermore, the mosquito control approach with Biogents traps and larval source management was significantly cheaper than the previously applied insecticide-based approach.

• Mass trapping: 6 BG-Mosquitaire CO2 traps per hectare and 7.2 BG-GAT traps per hectare
• Larval source management: habitat manipulation (construction of roofs, lids of septic tanks sealed)
• 2 clean-up campaigns (removal of potential breeding sites)
• Larviciding (neem oil applied on water surfaces)

Figure 1. Location of Kunfunadhoo island: Google Earth satellite image (imagery date 27 December 2018).

Figure 2. Inverse distance weighted heatmaps of Aedes albopictus showing areas with high (red) or low (green) mosquito catches by month for the period June 2019–June 2020.

Jahir A, Kahamba NF, Knols TO, Jackson G, Patty NFA, Shivdasani S, Okumu FO, Knols BGJ. Mass Trapping and Larval Source Management for Mosquito Elimination on Small Maldivian Islands. Insects 2022, 13, 805. https://doi.org/10.3390/insects13090805

CNN Travel article: A paradise island vacation with no mosquito bites – and no chemicals

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• Download poster: Insecticide-free Mosquito Elimination on Small Maldivian Islands (EMCA 2022)

Neighbors help neighbors control urban mosquitoes

Government-led programs to control dengue have often failed. Urban Aedes mosquitoes such as the yellow fever mosquito Ae. aegypti and the Asian tiger mosquito Ae. albopictus mainly breed in small containers on private properties. They are therefore a great species to be targeted by control programs that strongly rely on citizen participation.

The town of University Park, MD, USA used the BG-GAT traps in a citizen-based mosquito control intervention. The town is highly infested with Ae. albopictus and comprises approximately 1000 residential yards. Almost half of the town’s residential yards (439 of 954) were equipped with BG-GATs. Results indicate effective mosquito control, however, the reduction of mosquito nuisance was significantly higher in blocks where more than 80% of households used BG-GAT traps.

The approach named Citizen Action through Science (Citizen AcTS) is based on citizen volunteers that are mentored by scientific advisors. Residents were encouraged to purchase two BG-GAT traps (one for the front and one for the back yard). Each block of houses had a community leader that informed their neighbors about the initiative. Every participant was responsible for the installation and maintenance of the purchased traps.

Figure 1. Mean (±SE) female Ae. albopictus abundance during each collection point in high (≥80%) and low (<80%) coverage monitoring sites.

Johnson BJ, Brosch D, Christiansen A, Wells E, Wells M, Bhandoola AF, Milne A, Garrison S, Fonseca DM. 2018. Neighbors help neighbors control urban mosquitoes. Sci Rep. 8(1):15797. doi:10.1038/s41598-018-34161-9.

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Effectiveness of a field trap barrier system for controlling Aedes albopictus: biting pressure reduction to almost zero

A scientific study from southern France demonstrated the potential of Biogents traps to significantly reduce the number of received Asian tiger mosquito bites to almost zero.

Three houses with garden were treated with a network of BG-Mosquitaire CO2 traps for three months during the peak activity season of Ae. albopictus. The average distance between the traps was five meters. Three treated properties received 9, 13, and 18 traps, depending on their size. The trap network is called “Bio-Belt Anti-Moustique” and was patented by the French company HBM Distribution SAS.

The number of received mosquito bites in outdoor areas of the three treated houses was compared to the number of mosquito bites in three untreated houses with similar environments. After three weeks of continuous trapping, the number of mosquito bites was substantially reduced. After six weeks, the number of bites decreased to almost zero. The number of mosquito bites in the treated gardens was up to 93% lower than in the three houses without traps.

Fig 1. Biobelt traps installation in the treated houses — spatial schematic depiction of the array of the “belt” of traps around three treated houses.

Fig 2. Weekly mean number of Ae. albopictus bites per 30 minutes in three houses with BG-Sentinel trap barrier system and in three houses without traps in southern France, July–Sept 2016.

Akhoundi M, Jourdain F, Chandre F, Delaunay P, Roiz D. 2018. Effectiveness of a field trap barrier system for controlling Aedes albopictus: a “removal trapping” strategy. Parasit Vectors. 11(1):101. doi:10.1186/s13071-018-2691-1.

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Up to 87% reduction of Aedes albopictus nuisance in Italy (Cesena)

In Europe, Italy is one of the countries that are heavily infested with the day-active Asian tiger mosquitoes (Aedes albopictus). This study showed that it is possible to reduce biting rates and local populations of Aedes albopictus in Cesena, Italy, by using Biogents suction traps.

For the experiment, three small intervention sites with different characteristics were selected: a single-family house surrounded by a garden; an area dominated by apartment houses; and a cemetery. The study duration was 16 weeks from June to October.

Over the course of the whole study, an average of 11.2 Ae. albopictus per hour were collected in areas without Biogents traps, while only an average of 1.4 Ae. albopictus per hour were collected in areas with Biogents traps. This means that the overall biting pressure in intervention areas was reduced by 87%.

Figure 1. Mean number of Aedes albopictus bites per hour in human landing collection at three intervention sites treated with Biogents traps, and three similar sites without traps in Cesena, Italy.

Englbrecht C, Gordon S, Venturelli C, Rose A, Geier M. 2015. Evaluation of BG-Sentinel Trap as a Management Tool to Reduce Aedes albopictus Nuisance in an Urban Environment in Italy. J Am Mosq Control Assoc. 31(1):16–25. doi:10.2987/14-6444.1.

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Mass trapping of Dengue Vectors with BG-Sentinel Traps (Manaus, Brazil)

Aedes aegypti, the main vector of viral diseases such as dengue, Zika, and chikungunya is highly adapted to urban areas. Routinely employed dengue vector control strategies that usually consist of the reduction of breeding sites and application of insecticides have failed to control virus transmission in most settings, including Brazil. This long-term study shows that Biogents suction traps can reduce the abundance of Aedes aegypti in urban settings.

Six mass trapping areas (on average 60% of households received a Biogents suction trap) and six control areas (without trapping) were selected in the same neighborhood. The study was co-financed by the World Bank and conducted over 18 months in Manaus, Brazil.

Monitoring indicated that the mass trapping intervention significantly reduced the abundance of adult female Ae. aegypti during the first five rainy months of the study. The majority (88%) of 235 inhabitants from the mass trapping areas reported that the trap perceptibly reduced both mosquito density and nuisance.

Figure 1. Comparison of mean numbers of collected female Aedes aegypti in monitoring traps in six mass trapping areas and six reference areas before trap installation and during the first rainy season.

Degener CM, Eiras E, et al. 2014. Evaluation of the Effectiveness of Mass Trapping With BG-Sentinel Traps for Dengue Vector Control: A Cluster Randomized Controlled Trial in Manaus, Brazil. J Med Entomol. 51(2):408–420. doi:10.1603/ME13107.

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• 2014/03/27 press release (PDF)