AZEVEDO, Gisele Garcia, M.S., Universidade Federal de Viçosa, novembro de 1996. Flight activity and determination of number of larval instars in Partamona helleri (Friese): (Hymenoptera, Apidae, Meliponinae). Professor Orientador: Lucio Antonio de Oliveira Campos. Professores Conselheiros: Silvia das Graças Pompolo e Norivaldo dos Anjos Silva.

This work had as goals: to characterize the pattern of flight activity of P. helleri in the different seansons of the year determining which climatic factors are involved in this behavior and to characterize the larval development of P. helleri related to the number of instars. To the characterization of the flight activity, the number of bees entering and leaving three colonies was counted during six minutes in each hour. The environmental factors analised were temperature, light intensity, relative humidity, rainfall, evaporation and wind speed. The number of instars was determined using the measure of maximum width of the head capsule of 689 larvae collected from three different colonies. The model from Dyar's rule was used to the determination of real number of instars. Using this model, the growth rate (K) and the coefficient of determination (R²) were obtained. The results referring to the flight activity permitted the following conclusions: 1) the temperature was the principal factor that determined the seasonality in the pattern of flight activity of P. helleri; 2) the inner temperature of the colony had an indirect influence in the flight activity, as it was maintained during the cold months because of a great nectar collection, what permitted an increase of the metabolic activity inside the colony and, consequently, an increase of the temperature; 3) the alterations observed to the flight activity during the time of this study were probably due to the different effect of temperature in the mechanisms of body temperature regulation. Temperatures under 14C delayed the beginning of activity because they limit the gaining of an appropriate thoracic temperature to the flight, being this delay characteristic in the cold months. Temperature over 30C probably caused an overheating because the insufficient loss heat by convection, what causes a decrease of activity, characteristic in the hot months. Related to the determination of number of larval instars, the results obtained didn't permit any conclusion about the existence of four and, or, five instars in the larval development of P. helleri.