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International audience; Determining the abundance and distribution of male mosquitoes in the wild and establishing species seasonality in candidate pilot sites is of particular interest with respect to the use of the sterile-male technique. With the knowledge that using mice as bait in BG-Sentinel traps effectively enhances Aedes albopictus male and female trapping success, the present study was designed to determine whether attractants derived from mouse odour blend could be a viable substitute for live mice to lure Ae. albopictus mosquitoes into traps. The effects of baiting BG-Sentinel traps with mice, carbon dioxide (CO 2), and attractants derived from litter mouse odours (mouse litter (ML)) and a mouse odour blend (MOB) on the efficiency of trapping Ae. albopictus males and females were tested using a Latin square design. The BG-Sentinel trap baited with CO 2 + ML caught a significantly larger number of mosquitoes compared to traps baited with mice only. The BG-Sentinel traps containing only CO 2 or CO 2 + MOB, however, did not catch significantly more mosquitoes compared to the other traps. The proportions of males caught in the BG-Sentinel traps did not differ significantly between the respective attractants. The results from this study confirm that CO 2 bait is efficient to provide a reliable estimation method for Ae. albopictus adult male abundance in the wild, and suggest that mouse litter baits in combination with CO 2 could be used to enhance Aedes trapping success in BG-Sentinel traps.

Background Trapping male mosquitoes in the field is essential for the development of area-wide vector control programs with a sterile insect technique (SIT) component. To determine the optimal temporal and spatial release strategy, an estimation of the wild population density and its temporal dynamics is essential. Among the traps available for such data collection, the BG-Sentinel trap developed by the Biogents company uses a combination of visual cues, convection currents and olfactory signals. Although in numerous cases, this trap has shown high efficiency in sampling Aedes albopictus, in some cases low capture rates of Ae. albopictus males were recorded for the BG-sentinel mosquito trap baited with synthetic attractants. Methods The effects of modifying the BG-sentinel trap (by adding one mouse, two or three live mice to the trap) on the efficiency of trapping Ae. albopictus males and females was tested. The experiment was carried out in three distinct areas on La Réunion that have been selected for pilot field testing of the release of sterile male Ae. albopictus mosquitoes. The effect of four types of attractant (including the generic BG-Lure, one mouse or two to three mice) in baited BGS traps was tested with a Latin square design in order to control for the variability of different sampling positions and dates. Results At the three studied sites, the number of Ae. albopictus adults caught and the proportion of males per trap consistently increased with the number of mice present in the trap. Conclusion The results from this study suggest that some new attractants derived from, or similar to, mouse odors could be developed and tested in combination with other existing attractive components, such as CO2 and heat, in order to provide a reliable estimation method for Ae. albopictus adult male abundance in the wild. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1801-1) contains supplementary material, which is available to authorized users.