| Abstrakt: |
Abstract: a_1This was tested by comparing the relative importance of the differences in developmental time due to sex with the individual variation in development time in several randomly selected species. The differences in development time due to sex were mostly less important than individual variation. Only a small proportion of the differences due to sex could be ecologically significant. The sex-related variation in the relationship between temperature and developmental time in larvae, pupae and complete development of 97 non-diapausing species of insects is reviewed. The frequency of protandry and protogyny, the magnitude of differences and their importance relative to other sources of variation in developmental time were considered. There exist 6 temperature/developmental time relationships: protandric or protogynic development wit monotonous increase of decrease in the difference between the sexes with temperature, and development that switches from protandry to protogyny, or vice versa. The differences were recorded at a range of temperatures, from 5°C above the lower development threshold to +30°C. Protandry prevailed in larval (64% of all cases) and compete development (43%) and protogyny was rare (7 and 18%, resp.). Protogyny was commoner in pupal development (46%). Development with a switch between protandry and protogyny and vice versa occurred in 29% of the larval, 26% of the pupal and 38% of the complete developments. Due to the distribution of the temperatures for switching between protandry and protogyny over the range 10-30°C, the proportion of insects showing protandry in larval development increased with increasing temperature from ca 45% to ca 85%, but remained relatively stable for pupal development, between ca 35-45%. The proportion showing protandry in complete development increased slightly, from ca 55% to ca 70%. |
