Dilatação traqueal em três espécies de abelhas: Trigona spinipes, Scaptotrigona sp. e Apis mellifera

Abstract

During Earth's history, the oxygen concentration in the atmosphere oscillated to such an extent that the insect group began to morphologically adapt to the new oxygen concentrations over time. Thus, the most adequate mechanism for the breathing process by this group is the tracheal system, which is composed of a network of internal tubes connected to orifices that connect with the external environment, in order to capture the oxygen present in the atmosphere. Oxygen will be consumed to a greater or lesser amount bythe insects, depending on the intensity of their metabolicactivities. Among the most active insects are bees that constantly need a large intake of oxygen in order to meet their biological needs. The objective of this study was to evaluate the species of bees (Trigona spinipes, Scaptotrigona sp.and Apis mellifera) regarding their tracheal dilatation, comparing them to each other. The bees were captured through active collection, with a total of 150 individuals, 50 individuals of each species. The area of the collection was the surroundings of the Rural Federal University of Pernambuco, Campus Serra Talhada. Subsequently, the individuals were weighed on an analytical scale to obtain the initial mass value of each one. They were then placed in a 60-ml syringe with a valve attached and submerged in a solution containing 1% Triton X-100, in which movements of back and forth was performed in the syringe plunger, so that the liquid could enter in the animal's body and fill its entire tracheal system. The insects were weighed again to obtain the final mass. By weighing the individuals before and after being emerged in the solution, the tracheal dilatation (%) was obtained. Finally, it was observed that the native bees had a greater tracheal dilation compared to ape mellifera, and that this result could be related to a lower respiratory rate in the Meliponini species.