THE RELATIVE EFFICIENCIES OF LATIN SQUARE AND RANDOMIZED COMPLETE BLOCK-DESIGNS FOR INSECT TRAPPING EXPERIMENTS - AN INVESTIGATION USING FIELD DATA ON TSETSE-FLIES

1. The Latin square design (LSD) is usually preferred over the randomi zed complete block design (RCBD) in insect trapping experiments becaus e. of its ability to cater for variations due- to both sites and days in addition to treatments. 2. The efficiency of LSD relative to RCBD i s quantified for tsetse trapping experiments using a data set comprisi ng 2200 trap-days, LSD was found to be more efficient than RCBD when b locks = days, but less efficient when blocks = sites, especially when experiments involve only three or four treatments. 3. The importance o f sites relative to days as sources of variation in tsetse trapping ex periments is quantified. Effects due to site differences were shown to be more important than day to day variability. 4. By relating LSD rel ative efficiency to the relative importance of sites, it was found tha t LSD efficiency depended on the relative magnitude of effects of site s and days.