New aspects of the life-cycle of the flightless wing-polymorphic bug Pyrrhocoris apterus (L.) are described. It was found that 1.1-14.9% of the adult females of P. apterus in 11 samples collected from 4 populations in the South Bohemia had mated prior to entering diapause and their ovaries were in the pre-vitellogenic stage of development with viable sperm in their spermathecae. Some of these females successfully overwintered. The percentage of overwintering females that had been fertilized ranged from 1.1 to 7.2 % and depended on the month and year of collection. The results indicate that pre-diapause mating and overwintering of fertilized females is not unusual in populations of P. apterus in the Czech Republic and and that sperm in overwintering female survives for at least 7-8 months.