Distribution of Larval Habitats and Efficiency of Various Trap Settings to Monitor Sympatric Aedes albopictus and Aedes aegypti in La Reunion

To prepare for a boosted sterile insect technique (SIT) field trial in Saint-Joseph, Reunion island, we compared the attractiveness of two adult mosquito traps for <i>Aedes albopictus</i> and <i>Aedes aegypti</i>. In addition, we explored the co-occurrence of these species in their usual larval habitats. Two traps were compared with two conditions each using a Latin square design: BG Sentinel trap baited with carbon dioxide (CO₂) with/without addition of BG Lure and ovi-sticky trap with/without hay. The ovi-sticky traps proved ineffective. For both <i>Aedes</i> species, CO₂-baited traps were equally effective at catching females when baited with the lure or not. In contrast, they were more attractive to males than for females with the lure. <i>Aedes aegypti</i> larvae were found in four of six vacoas (<i>Pandanus utilis</i>), and one of four anthropogenic breeding sites. In vacoas, the densities of <i>Aedes albopictus</i> and <i>Aedes aegypti</i> larvae were negatively correlated, whereas the correlation was positive between chironomids and <i>Aedes aegypti</i>. The abundance of adults and larvae varied according to weather conditions. Finally, CO₂-baited traps were used without lure for the entomological monitoring to assess the effectiveness of the area-wide boosted SIT intervention to reduce costs and logistics.