The Japanese dung beetle, Copris pecuarius, has a large number of olfactory sensilla in the periphery of the 7th and 8th segments of the antennae. The length of each sensillum ranges from 12 to 23μm and the diameter from 2.5 to 3μm at the base. The number of sensilla on the 7th segment varies from 1, 600 to 1, 900. Small olfactory pores are distributed on the surface of the sensilla. Olfactory cells in a sensillum reacted well to odor of cow dung and 2-butanone. Unitary impulses were 1 to 10mV in height and 2 to 2.5msec in duration.
Mass-rearing procedure of the melon fly requires sifting of puae from the sawdust in which they pupated. The sifting of 1-to-2-day-old pupae reduced the eclosion rate and that of 3-to-4-day-old pupae was harmful to the flight ability of the adult which emerged, when the pupal duration lasted is 9 days at a rearing temperature of 25°C. The flight ability of the adult was not retarded after the 3rd day of eclosion in sifting lasting 1.5 and 10min, respectively. On the basis of these result, it was concluded that the pupae should not be sifted before the 5th day after pupation.