Bridging laboratory and field research: Method adjustments to blood feed field-derived Aedes aegypti

Reference strains of Aedes aegypti, reared over decades under laboratory conditions, are commonly used in research due to their consistency and ease of handling. While their use is relevant in terms of reproducibility between labs, complementary work on field-collected mosquitoes and their progeny is essential to capture biological and behavioral variations of natural populations. However, experimental set-ups optimized on reference strains are not always successful with field-derived mosquitoes; their lack of attraction to experimental blood meals is a recurrent issue. In this study, we evaluated methods to improve blood-feeding rate of field-derived mosquitoes from Cayenne (French Guiana), using the New Orleans reference strain as a control. We tested the impact of several blood-feeding systems for mosquitoes kept in a cage or in individual vials and adjusted starvation parameters. Individual mosquitoes offered a blood meal in lids of microtubes had the highest blood-feeding rate. For field-derived mosquitoes, starvation, or alternatively, provision of a 3% salt solution instead of the sugar solution, also consistently improved blood-feeding rate, with a minimal impact on survival. Our results may be helpful for establishment of new colonies, including in resource-limited settings, studies on fitness of field-derived mosquitoes and on experiments requiring individual level monitoring.