Biotropica 18(1): 28-31 (March 1986)
Nectar Production and Temperature Dependent Pollination in Mirabilis jalapa L.
Carlos Martinez del Rio and Alberto Búrquez

The influence of temperature and nectar production on the pollination of Mirabilis jalapa L. (the four o'clock) is documented for a Central Mexico population. Below about 13°C at dusk, pollen transfer was nil because the hawkmoths that pollinate the plant failed to fly. Between 13°C and 21°C the pollination efficiency increased linearly with dusk temperature. As M. jalapa is capable of selfing, the breeding structure of the population seems to depend on temperature conditions, being autogamous on cool nights and allogamous on warm nights.

For a particular temperature the activity of the hawkmoths was dependent on nectar availability, their maximum rate of activity occurring after the maximum rate of nectar production.

Mirabilis bibliography