Mating Rate
Curves undulated differently from the mating rates of the 14 age combinations of female and male (Fig. 1). Mating rates were higher from 21:00 to 7:00, and lower from 7:00 to 19:00. The mating rates were affected by age of female and male. Mating was most likely to take place between females and males that were 1-d old. It can be seen in Figure 1 that some of the age-delayed couples could mate during day time, especially the female age-delayed couples. Results from the choice experiment showed that males of different ages unanimously select 1-d-old females to copulate.