Semi-field assessment of the Gravid Aedes Trap (GAT) with the aim of controlling Aedes (Stegomyia) aegypti populations

Abstract

The mosquito Aedes aegypti is the main vector of arboviroses and current approaches to control this vector are not sufficiently effective. Adult traps, such as the BG-Sentinel (BGS), have been successfully used for mosquito surveillance and can also suppress vector populations. A new “passive” trap for gravid Ae. aegypti (Gravid Aedes Trap—GAT) has been shown efficient for Aedes collection and suppress Ae. albopictus populations using mass trapping techniques. Here the GAT was evaluated for the first time as a new tool to control Ae. aegypti in semi-field conditions using simulated outdoor environments (SOE). Two identical large screened chambers inside of a SOE containing different numbers and sizes of artificial breeding sites were used to assess the trapping efficiency of the GAT. One hundred mosquitoes were released into the chambers, and recapture rates evaluated after 48h. The parity status of the captured mosquitoes was also recorded. The number of eggs laid, and breeding productivity were also monitored when using different numbers and sizes of breeding sites. The BGS trap was used here as a control (gold standard) trap to compare capture rates to those of the GAT. The GAT recaptured between 50–65% of the mosquitoes independent of the number and sizes of the breeding sites in the SOEs, whereas the BGS recaptured 60–82% of the females. Both traps showed similar results regarding to the parity status of recaptured mosquitoes. Our results confirmed the effectiveness of GAT for the capture of adult female Ae. aegypti in simulated field environments. The BGS trap recaptured gravid Ae. aegypti before egg-laying in different sizes and number of breading sites, whereas the oviposition activity occurred prior to recapture mosquitoes in the GAT. Based on the results, we believe that GAT is a promising candidate for mass-trapping intervention in urban settings, but a source reduction intervention should be made prior trap deployment. Therefore, we suggest future field studies to confirm the use of GAT as a complementary tool in vector control activities.

Unravelling the mosquito-haemosporidian parasite-bird host network in the southwestern Iberian Peninsula: insights into malaria infections, mosquito community and feeding preferences

“…Overall, Extremadura has a Mediterranean climate, characterized by a long dry summer season and higher levels of precipitation in winter, according to the Köppen climate classification [ 47 ]. Insects were captured using BG-Sentinel and Center for Disease Control (CDC) incandescent light-traps baited with dry ice as source of CO 2 and gravity traps baited with a hay infusion prepared by incubating 0.5 kg of hay in 114 l tap water for 5 days [ 48 , 49 ]. Five sampling sessions were conducted at each site, resulting in a total trapping effort of 25 trapping nights.…”

From tissue engineering to mosquitoes: biopolymers as tools for developing a novel biomimetic approach to pest management/vector control

“…These artificial oviposition sites have been converted from monitoring to a lethal ovitrap (LOT) [79] by adding an insecticidal ingredient (chemical or biological) [80], obtaining a low-cost device proven (under certain conditions) to reduce mosquito population density in large-scale campaigns [48]. However, their efficacy is strongly dependent on public engagement and larval source reduction from the environment [62,81]. LOT efficacy can increase when enriched with organic infusions such as grass, hay, or oak, as well as NPK (nitrogen-phosphorous-potassium) fertilisers, to improve their attractivity [82,83].…”

“…However, although more selective, they remain largely based on chemical insecticides [88], with consequently higher environmental impact and a lower safety profile compared to insecticide-free approaches such as active lethal traps, limiting their applicability in domestic contexts. Although biopesticides such as Bti and Wolbachia have been proved effective against Aedes, no specific improvements to traps (e.g., trap design or oviposition substrate modifications) have been proposed to promote their use or to employ other active substances [79,81].…”

Proof of Concept of Biopolymer Based Hydrogels as Biomimetic Oviposition Substrate to Develop Tiger Mosquitoes (Aedes albopictus) Cost-Effective Lure and Kill Ovitraps

“…We claimed that the hydrogel-based oviposition substrate could be more effective than a simple and not specially designed substrate. Furthermore, we supposed that this approach could promote the choice of ovitraps and bioinsecticides as a mass control method [ 50 , 51 , 52 , 53 , 54 , 55 , 56 ]. Not just by providing a more attractive oviposition substrate but else too by reducing ovitraps’ costs for maintenance by extending their working period (e.g., through hydrogel’s water retention ability), avoiding the disposal (through biodegradation), and by supporting the activity of the bioinsecticide to improve its efficacy in field conditions.…”