Apparent limitations of molluscicides against Oncomelania snails, imposed by environmental conditions, have prompted increased emphasis on fundamental studies of snail biology (McMullen, 1952; McMullen et al., 1953). It is possible that derived information, when properly integrated with agricultural practices, engineering pursuits and methods of applying molluscicides, will suggest more effective control of schistosomiasis japonica.
Extensive investigations on morphology, bionomics, reproduction and control of Oncomelania are currently being undertaken by several agencies. The nature and results of these, which are presently available only as progress reports or personal communications, will be incorporated with a general review of the literature.
Biologic Studies of Oncomelania. Morphology. Morphologic studies, such as those of Li (1934) and Abbott (1948), are being reviewed and extended at the 406 MGL as a basis for determining pathogenesis elicited by molluscicides.