Patterns of Intranidal temperature fluctuation for Melipona beecheii colonies in natural nesting cavities
Humberto Moo-Valle; José Javier G Quezada-Euán; Jorge Navarro; Luis A Rodriguez-Carvajal;
Intranidal temperature fluctuation was studied in colonies of Melipona beecheii, an economically important stingless bee from Yucatan, Mexico. Two feral colonies nesting in tree cavities were used in the experiments. The brood and storage pots inside the nests were monitored for temperature changes using a telethermometer. Ambient temperatures immediately outside the logs were recorded simultaneously with thermohygrometers. Temperatures were recorded every hour for 24 h on four non-consecutive days. Differences between ambient temperatures and temperatures within nests were noted during the day and night. In all cases temperatures in brood and storage pots area were different from the ambient temperature (P <0.01). There was no significant relationship between intranidal and ambient temperatures during the day (09.00 h to 20.00 h) on all days of measurement (P > 0.01). However, during lower ambient temperatures at night (21.00 h to 08.00 h) intranidal and ambient temperatures were significantly correlated (P < 0.01). These findings indicate that temperatures inside natural nesting colonies of M. beecheii remain relatively stable during the day, but tend to vary at night. Colony temperatures at night may lag from 5-6 h behind ambient temperatures. Active temperature control in nests of M. beecheii thus seems unlikely, and therefore the ability to ensure stable temperatures within the nest might be an important factor limiting the successful adaptation of this species to hive culture.
stingless bees, Melipona beecheii, temperature fluctuation, intranidal thermoregulation, Yucatan, Mexico