Njoroge : Yeast RNAi-based Attractive Targeted Sugar Baits (ATSBs) for Mosquito Control
Yeast RNAi-based Attractive Targeted Sugar Baits (ATSBs) for Mosquito Control
Indiana University School of Medicine-South Bend
Teresia Njoroge; Keshava Mysore and Molly Duman Scheel, Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, IN and
David Severson, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN
Attractive targeted sugar baits (ATSBs) exploit the intrinsic sugar feeding behavior of female and male mosquitoes, which can be lured to feed on a sugar source laced with an insecticide. In recent years, we have identified hundreds of RNAi-based pesticides, several which target genes required during both the developing and adult stages of the mosquito life cycle. A subset of the RNAi pesticides has target sites that are conserved in different species of disease vector mosquitoes, but which are not found in humans or other non-target organisms. These interfering RNA pesticides (IRPs), which were designed to be mosquito-specific, have the potential to enhance existing ATSB technology, combat pesticide resistance, and reduce the burden of mosquito-borne illnesses.
Short hairpin 463 matching the shaker gene with a conserved target site in An. gambiae, Ae. aegypti, ae. albopictus, Culex pipiens and Cx. quinquefasciatus was expressed in Saccharomyces cerevisiae (baker’s yeast). The yeast was propagated, heat inactivated and fed to larvae, as well as adult An. gambiae, Ae. aegypti, Ae. albopictus, Culex pipiens and Cx. quinquefasciatus adult mosquitoes. For the adult mosquitoes, the yeast (active ingredient) was mixed with an attractive sugar bait and presented to the adults orally on petri plates.
Consumption of 463 yeast IRP resulted in significant An. gambiae, Ae. aegypti, ae. albopictus, Culex pipiens and Cx. quinquefasciatus larvae and adult mosquito deaths (90-100% mortality). Additionally, the sh. 463-yeast insecticide was not toxic to non-target arthropods (honeybees, milkweed bugs and red flour beetle).
Although the yeast based ATSBs are toxic to Aedes, Anopheles, and Culex mosquitoes, in which they disrupt neural function, the insecticides have not been found to be toxic to non-target arthropods.
Translational/Human Health Impact:
Yeast based- RNA interference RNA pesticides are novel mosquito specific insecticides for disease vector control. They are excellent candidates for biorational mosquito control and are a perfect addition to the mosquito control toolbox. They can be used alone or in combination with other mosquito control methods to combat mosquito-borne diseases.