Frequent sugar feeding behavior by Aedes aegypti in Bamako, Mali makes them ideal candidates for control with attractive toxic sugar baits (ATSB)

Abstract

Background Current tools and strategies are not sufficient to reliably address threats and outbreaks of arboviruses including Zika, dengue, chikungunya, and yellow fever. Hence there is a growing public health challenge to identify the best new control tools to use against the vector Aedes aegypti . In this study, we investigated Ae . aegypti sugar feeding strategies in Bamako, Mali, to determine if this species can be controlled effectively using attractive toxic sugar baits (ATSB). Methodology We determined the relative attraction of Ae . aegypti males and females to a variety of sugar sources including flowers, fruits, seedpods, and honeydew in the laboratory and using plant-baited traps in the field. Next, we observed the rhythm of blood feeding versus sugar feeding activity of Ae . aegypti in vegetation and in open areas. Finally, we studied the effectiveness of spraying vegetation with ATSB on Ae . aegypti in sugar rich (lush vegetation) and in sugar poor (sparse vegetation) urban environments. Principal findings Male and female laboratory sugar feeding rates within 24 h, on 8 of 16 plants offered were over 80%. The survival rates of mosquitoes on several plant sources were nearly as long as that of controls maintained on sucrose solution. In the field, females were highly attracted to 11 of 20 sugar sources, and 8 of these were attractive to males. Peak periods of host attraction for blood-feeding and sugar feeding in open areas were nearly identical and occurred shortly after sunrise and around sunset. In shaded areas, the first sugar-seeking peak occurred between 11:30 and 12:30 while the second was from 16:30 to 17:30. In a 50-day field trial, ATSB significantly reduced mean numbers of landing / biting female Ae . aegypti in the two types of vegetation. At sugar poor sites, the mean pre-treatment catch of 20.51 females on day 14 was reduced 70-fold to 0.29 on day 50. At sugar rich sites, the mean pre-treatment catch of 32.46 females on day 14 was reduced 10-fold to a mean of 3.20 females on day 50. Conclusions This is the first study to show how the vector Ae . aegypti depends on environmental resources of sugar for feeding and survival. The demonstration that Ae . aegypti populations rapidly collapsed after ATSB treatment, in both sugar rich and sugar poor environments, is strong evidence that Ae . aegypti is sugar-feeding frequently. Indeed, this study clearly demonstrates that Ae . aegypti mosq...

Ingested insecticide to control Aedes aegypti: developing a novel dried attractive toxic sugar bait device for intra-domiciliary control

“…Early field trials did not show a positive effect of ATSBs on Ae. aegypti [26,27]; however, a recent field trial in Bamako, Mali, showed promising success [31]. The principle barrier to field trial success appears to be the ability to attract Ae.…”

“…Despite this, Ae. aegypti females will readily feed on sugar in the laboratory, and often feed on plant sugars in the wild [28][29][30][31]. However, traditional attractive sugar bait strategies that rely only on fruit volatiles as an attractant are likely insufficient to "lure" highly anthropophilic female Ae.…”

Large-scale field trial of attractive toxic sugar baits (ATSB) for the control of malaria vector mosquitoes in Mali, West Africa

“…Wells that stayed yellow were considered negative. For a visual indicator of blue colour change see [34].…”

Characterization of a dual-action adulticidal and larvicidal interfering RNA pesticide targeting the Shaker gene of multiple disease vector mosquitoes

“…This could bring the mortality rates of A. aegypti mosquitoes treated with Sh.463 ATSB to 100% in the field. We hope to evaluate this in A. aegypti field trials in the future, as several studies suggest that ATSBs are an effective means of controlling A. aegypti [44,45].…”