Fig. 2. Rough texture preference is maintained at small scales. (A) Representative images of split Petri dishes used to assay egg-laying preference between substrates differing in average particle size. Each dish contained two halves, each patterned with a texture with a defined average particle diameter as indicated. (B) Egg-laying PI of mosquitoes offered split-Petri dishes with the indicated textures. For each boxplot, the relative texture difference of the two halves is represented by the colour scale on the right. (C) Log–logistic function (fixed upper bound of 1 and lower bound of 0) fitted to the egg-laying preference data shown in B [slope=−2.169; ED50=62.77 μm]. The green line represents the curve fit, while light green shading represents the 95% confidence interval of the fit. Circles and whiskers are the means and 95% confidence interval of the original data. Note the similarities to the function from Fig. 1C. n=5–10 per condition.
ABSTRACT
Mosquitoes undergo development as aquatic larvae and pupae before emerging as terrestrial adults. Accordingly, blood-fed and mated female mosquitoes must select an appropriate egg-laying site to maximize the fitness of their offspring. Female yellow fever mosquitoes (Aedes aegypti) lay their eggs above the waterline of small containers or natural bodies of water, where they can remain dormant for many months until they are submerged and hatch. Here, we show that female mosquitoes use surface texture as a powerful cue to guide egg-laying decisions, selecting rougher textures over smooth when choosing among containers and when selecting specific sites within a given substrate. In addition, we identify an interaction between substrate texture and water salinity with respect to egg-laying decisions, demonstrating that female mosquitoes integrate competing cues to determine the ultimate suitability of an egg-laying site. Finally, we explore the dynamics of local egg-laying search behaviour, demonstrating that texture modulates traversal speed while mosquitoes search for appropriate egg-laying sites.