K bar coating of fungal spores. (A) The stainless steel K-bar with wired grooves (inset) that control film thickness. (B) Automated (left) and manual K-Coater (right). (C) Application of fungal spore suspension on the centre top part of the paper substrate with a pipette. (D) Coating a paper substrate with spore suspension using a swift top-to-bottom movement of the bar using light pressure. (E) The mosquito exposure set-up with a coated paper inside a PVC tube (right), sealed with plastic foil. Mosquitoes were transferred into the holding tube with an aspirator and (after exposure) to the holding buckets (left) via free flight.