A series of tests in tubs (semi-natural conditions for test snails) was run for approximately two years to determine the relationship of temperature to molluscicidal activity of dinitro-o-cyclohexylphenol (DCPH), sodium-pentachlorophenate (NPCP) and copper sulfate (CuSO4), at 3 ppm., against the snail, Biomphalaria boissyi, in Egypt. The mean percentages of mortality among snails exposed to these toxicants was markedly increased with elevation of temperatures in the test tubs of artificial as well as by natural (seasonal) heating. Similar relationships were apparent when molluscicides were applied in test plots or sections of irrigation canals at different times of the year. In the interest of molluscicidal efficiency and economy, temperature should be considered in the practice and in the planning of snail control programs in the field.
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