Does membrane feeding compromise the quality of Aedes aegypti mosquitoes?

Abstract

Modified Aedes aegypti mosquitoes are being mass-reared for release in disease control programs around the world. Releases involving female mosquitoes rely on them being able to seek and feed on human hosts. To facilitate the mass-production of mosquitoes for releases, females are often provided blood through artificial membrane feeders. When reared across generations there is a risk that mosquitoes will adapt to feeding on membranes and lose their ability to feed on human hosts. To test adaptation to membrane feeding, we selected replicate populations of Ae. aegypti for feeding on either human arms or membrane feeders for at least 8 generations. Membrane-selected populations suffered fitness costs, likely due to inbreeding depression arising from bottlenecks. Membrane-selected females had higher feeding rates on membranes than human-selected ones, suggesting adaptation to membrane feeding, but they maintained their attraction to host cues and feeding ability on humans despite a lack of selection for these traits. Host-seeking ability in small laboratory cages did not differ between populations selected on the two blood sources, but membrane-selected females were compromised in a semi-field enclosure where host-seeking was tested over a longer distance. Our findings suggest that Ae. aegypti may adapt to feeding on blood provided artificially, but this will not substantially compromise field performance or affect experimental assessments of mosquito fitness. However, large population sizes (thousands of individuals) during mass rearing with membrane feeders should be maintained to avoid bottlenecks which lead to inbreeding depression.

Artificial Feeding of All Consecutive Life Stages of Ixodes ricinus

“…However, as F 0 ticks showed a lower attachment proportion than F 1 ticks in both incubator and water bath, seasonality might also play a role, as F 0 ticks were fed during winter and F 1 ticks during summer. Another possible explanation might be an adaptation of ticks to in vitro feeding, as was for instance reported for mosquitos [ 51 ].…”

Persistent deleterious effects of a deleterious Wolbachia infection

“…The wMelPop infection reduces female blood feeding success and affects probing behaviour, particularly in older females [31,32]. We evaluated blood feeding traits in 5 and 35 d old females according to methods described previously [33]. We recorded pre-probing duration (time from landing to insertion of the proboscis), feeding duration, blood meal weight and proportion feeding.…”

Feeding and Quantifying Animal-Derived Blood and Artificial Meals in <em>Aedes aegypti</em> Mosquitoes

“… For animal-derived blood meals, transfer 1.98–2 mL defibrinated sheep blood into a 15 mL conical tube (see step 3.3 for desired volume of blood). NOTE: Commercially defibrinated sources of vertebrate blood, including from sheep, guinea pigs, and humans, may be used 13 . Prior to use, ensure that the purchased blood has not passed its expiry date and mix it well by inverting the bottle, especially if there is visible separation of blood components.…”

“…Many laboratory protocols for mosquito rearing and experimentation use live animals including mice, guinea pigs, or humans as a blood source 13 , 14 , 15 , 16 . The use of live animals imposes ethical concerns as well as complex requirements for personnel training, animal housing and care, and compliance with Institutional Animal Care and Use Committee (IACUC) policies.…”