Long-Term Mosquito culture with SkitoSnack, an artificial blood meal replacement

Abstract

The reliance on blood is a limiting factor for mass rearing of mosquitoes for Sterile-Insect-Technique (SIT) and other mosquito-based control strategies. To solve this problem, we have developed SkitoSnack, a formulated diet for Aedes aegypti (L) mosquitoes, as an alternative for vertebrate blood. Here we addressed the question if long-term yellow fever mosquito culture with SkitoSnack resulted in changed life history traits and fitness of the offspring compared to blood-raised mosquitoes. We also explored if SkitoSnack is suitable to raise Asian tiger mosquitos, Aedes albopictus (L.), and the human bed bug, Cimex lectularius (L). We measured life history traits for 30 th generation SkitoSnack-raised Ae. aegypti and 11 th generation SkitoSnack-raised Ae. albopictus, and compared them with control mosquitoes raised on blood only. We compared meal preference, flight performance, and reproductive fitness in Ae. aegypti raised on SkitoSnack or blood. We also offered SkitoSnack to bed bug nymphs. We found that long-term culture with SkitoSnack resulted in mosquitoes with similar life history traits compared to bovine blood-raised mosquitoes in both species we studied. Also, Ae. aegypti mosquitoes raised on SkitoSnack had similar flight performance compared to blood raised mosquitoes, were still strongly attracted by human smell and had equal mating success. Minimal feeding occurred in bed bugs. Our results suggest that long-term culture with the blood-meal replacement SkitoSnack results in healthy, fit mosquitoes. Therefore, artificial diets like SkitoSnack can be considered as a viable alternative for vertebrate blood in laboratory mosquito culture as well as for mosquito mass production for Sterile-Insect-Technique mosquito control interventions. SkitoSnack was not suitable to induce engorgement of bed bugs.

Ad libitum consumption of protein- or peptide-sucrose solutions stimulates egg formation by prolonging the vitellogenic phase of oogenesis in anautogenous mosquitoes

“…We initially fed starved UGAL Ae. aegypti a single protein-sugar meal to repletion because prior studies using artificial blood meals or protein-sugar solutions have fed females in this way [ 19 , 21 , 25 , 29 – 31 ]. However, this approach mimics blood-feeding more than nectar feeding in the field or sugar feeding in laboratory, which is why we also conducted assays where females had ad libitum access to protein-, peptide- or amino acid-sugar solutions [ 6 ].…”

“…Protein-rich solutions have been developed as artificial blood meals for use in membrane feeders that, with warming and inclusion of ATP as a phagostimulant, induce Aedes, Anopheles and Culex spp. to feed and produce eggs with varying levels of efficacy [ 16 – 25 ]. Studies dating back more than a century indicate some anautogenous mosquitoes also consume protein without heating or ATP if added to a sugar solution, which likewise results in egg formation [ 25 – 31 ].…”

“…to feed and produce eggs with varying levels of efficacy [ 16 – 25 ]. Studies dating back more than a century indicate some anautogenous mosquitoes also consume protein without heating or ATP if added to a sugar solution, which likewise results in egg formation [ 25 – 31 ]. The literature thus overall suggests protein acquisition rather than a specific requirement to blood-feed determines whether female mosquitoes can produce eggs.…”

A simple and affordable method for estimating the fluid volume a mosquito sucks using food dyes

“…For example, the green dye we used in this study consisted of Tartrazine (8.6%) and Brilliant Blue FCF (3.4%), which are the approved food additives. Other commercially available food dyes were also used in artificial food, which can become a substitute for animal blood to rear mosquitoes, showing that these food dyes do not exhibit any negative effects on the mosquito life cycle for many generations [ 23 , 24 ]. The fact that most food dyes are easily accessible may expand the availability of membrane feeding of mosquitoes to a range of other experiments.…”

“…On the other hand, it appears that any dyes may fail to label the intact blood which is a dark shade of red. Recently, artificial blood diets were developed for rearing mosquitoes [ 23 , 24 , 26 ]. One of these is an ATP-supplemented plasma and effective even after extended storage in refrigerated, frozen, or lyophilized conditions.…”