Figure 5.—

Viabilities of C. briggsae, C. sp. 9, and F1₉ hybrids at different temperatures. Viability was measured as the number of adults resulting from the total number of embryos laid. All hybrid F1₉ were generated from crossing C. briggsae males to C. sp. 9 females. Error bars represent 95% confidence intervals. The lines C. sp. 9 JU1325 and C. briggsae AF16 were used for all observations. Sample sizes at temperatures 15°, 17°, 20°, 22.5°, 25°, and 27°, respectively: C. briggsae AF16 (342, 1883, 377, 867, 472, and 1800); C. sp. 9 JU1325 (136, 1078, 2312, 1396, 534, and 1616); and hybrid F1_b (174, 195, 1004, 162, 510, and 383).