The eggs were obtained from bloodengorged females collected in the field or developed in an insectarium, as shewn in Table 1. These midges were anesthetized with chloroform, and then selected females were decapitated on a wet fiIter paper to make them lay eggs CMorii and Kitaoka, 1968). Newly laid eggs were immediately fixed in 1% (vfv) glutaraldehyde solution buffered with O. 1 M phosphate buffer (pH 7.2) at 4eC overnight. After rinsing in 3 changes of O,1M phosphate buffer fer 30