and throughout installation the tubing 11 is provided with periodic apertures or perforations 22 which serve as outlet ports for the emission into concealed building areas of pesticide in a manner described below the perforations 22 are preferably spaced every 12 inches to ensure that at least one perforation 22 will be located in each wall void 24 for standard stud spacings of 16 or 24 inches center to center other spacings are of course possible however greater spacings e g every 15 inches can lead to two perforations in one wall void 24 and no perforations in an adjacent wall void 24 39 see fig2 smaller spacing e g 6 inches or 8 inches will give the desired at least one perforation per wall void but will result in a decrease in pressure along the tubing length for expulsion of the pesticide material one end of each tubing length is closed as shown in fig3 the other open end is connected to a receptacle 20 this may be accomplished simply as shown utilizing conventionally available materials the 1 8 inch diameter tubing can for example be doubled over to form the closed end 25 and a sleeve in the form of a short length of 1 4 inch standard drip irrigation tube 26 is then slipped over to secure the same the other end 27 is then mounted in an accessible manner to receptacle 20 the end 27 may for example be brought into the serrated wall inserted expanding end of a 1 4 inch plastic anchor 28 which is inserted coaxially into a standard 1 4 inch cable bushing 29 positioned within an opening 30 of.