Pronto Plus Bedbug & Dust Mite Killer, Regular Size 10 oz (Pack of 3) Pronto kill bedbugs apply at cracks and crevices around baseboards, floorboards, headboards and walls. It is first thoroughly clean and air mattresses and springs. Pronto Kill Bedbugs And Dust Mites Spray kill bedbugs and dust mites where they hide. It is kill bedbugs apply as a spot treatment to cracks and crevices around baseboards.