Feeding Haematobia irritans (Diptera: Muscidae) adults through a nylon-reinforced silicone membrane

A nylon-reinforced silicone membrane used to feed Haematobia irritans (L.) adults was found to be equally effective as the currently used blood-soaked cotton method. Membranes consisted of nylon bridal veil embedded in a thin layer of clear silicone caulk prepared by pressing bridal veil and silicone caulk bead between two brass rollers, using Parafilm and office paper as support materials. Membrane thickness was regulated by varying the space between the brass rollers. Feeding success was measured by adult survival, fecundity, and fertility during 10-d experimental periods. Adults fed successfully through 0.02-, 0.03-, and 0.06-mm-thick membranes, but not 0.08- and 0.11-mm-thick membranes. More larvae were produced by flies that were presented the rough surface than the smooth surface if the membranes were 0.03 or 0.06 mm thick. Similarly, female and male survival was higher when the rough membrane surface was presented. Female survival was unaffected by thickness (between 0.02 and 0.06 mm), whereas male survival decreased as thickness increased. Membranes that were 0.03 and 0.06 mm thick leaked at a greater rate if the smooth surface was presented to the flies, and 0.02-mm-thick membranes leaked regardless of the surface presented. When adults were maintained at a density of 0.42 fly per cm3, larval production was maximized when 22 flies were feeding per 1.0 cm2 of membrane surface. It was not possible to determine the optimum fly density per 1.0 cm2 of membrane surface when flies were maintained at a density of 0.10 fly per cm3.