A temperature-controlled membrane feeding apparatus for use with blood-sucking arthropods is described which is relatively simple in design, efficient, and trouble-free. Easily constructed from an ordinary Mason-type fruit jar, readily available laboratory glassware, and unsophisticated electrical parts, its construction is economical and involves no special techniques. An electric heater coil for raising temperature of the blood to body heat is built into each feeding device and other than flexible connecting wires, no troublesome linkage such as is used with hydraulic systems is employed. By means of a variac, the temperature can be adjusted with ease. The feeding arthropods have access to a maximal membrane surface area, so the device is adaptable to mass feeding of colonized vectors. A variety of membranes, either artificial such as a rubber condom, or of animal origin such as sheep caecum or pig intestine, can be employed, depending on the type of arthropod with which the device is used. Arthropods used in this study included Rhodnius prolixus, Cimex lectularius, Culex pipiens, and Omithodorus moubata.