Figure 1.

Daily patterns in cercarial emergence (recalculated to 1 hour) of Trichobilharzia sp. “peregra” from individuals of Radix balthica snails (marked with different line colors) during diel intervals (Sr, sunrise; D, day; Ss, sunset; N, night) under field and laboratory conditions in (a) August 2016, (b) August 2017, (c) August 2018, and (d) October 2018. Cercarial emergence during the longest parts of the natural photoperiod in summer (day interval in August) and autumn (night interval in October) are divided into half and termed as D1, D2 and N1, N2. Note the different number of experimental days in August 2016 (see also Table 1). The emergence data from October 2018 are not shown due to a single snail producing cercariae in similar numbers during a single day (see Appendix A Table A1). “ln” refers to ln-transformed number of emerged cercariae per hour.