Aspects of the behaviour and biology of C.brevitarsis were studied with the aim of establishing a laboratory culture. It was shown that gravid females discover dung pats, the breeding site of the larvae and pupae, visually and probably while flying over the pat. The curvature of the edges of the pat was shown to be important to its recognition, whereas shape in plain view was not. Oviposition occurred throughout the whole day, with the highest rates during the afternoon and early part of the night, and continued throughout the 6 days after the pat was dropped. Larvae and pupae were distributed throughout the pat but with very few in the crust and a tendency for pupae to be concentrated in the wet-caneite zone. Pupation and eclosion were described in detail. Eclosion occurred during the afternoon sometimes extending into the early evening, and was accelerated by exposure to bright light (especially 60,000 lux).
Mature spermatids were present in the vesicula seminalis 24 hours after emergence at which time all of the stored food had been consumed in both males and females held in the laboratory. Mature spermatids were 90µm long but extremely narrow.
Swarming, presumed to be the time and place of mating, was examined in detail. The most common marker was shown to be the sunward boundary of a zone of very low reflected light, the most usual source in the field being shadows. Cattle grossly altered swarming by reducing the height of and distance between swarms, and increasing the number of males and the likelihood that females will be present in them. The upper limit of wind speed at which swarming would occur was 2.47 ms- 1. Swarming occurred during the hour preceding sunset. Females obtained a blood meal from cattle starting ½ an hour before and continuing to as late as 6 hours after sunset. The majority (97%) of
females collected from cattle were already mated. Flies fed on the top of the animal near its tail with their density falling very rapidly down the host's side but less rapidly towards its head. Oogenesis was described with particular reference to changes in size, the development of the secondary ovum, and changes during sclerotisation of the primary ovum. The development of small structures, called ansulae, on the surface of the egg was examined, and it was proposed that they formed a plastron layer. The longevity of adults fed on various diets in the laboratory was determined, both sexes living for a mean of 8.9 days when offered sugar solution.