The number of xo alleles of a population of stingless bees can be estimated by observing the male proportion of the first brood comb produced by a new queen (about 40 Fl bees) and the total number of colonies. A proportion of 50% diploid males indicates insemination of the queen by a single male with some xo sex allele: 25% diploid male would indicate insemination by two males (one with some xo as the queen and another with different one). Diploidy was confirmed by cytology of the testis. The original population (78 colonies) of Ribeirão Preto, State S. Paulo, Brazil, had 8 xo sex alleles. From this population, 10 colonies were orphaned and taken to the Serra do Mar (Sea Mountains) at Espirito Santo State (1200 km far) in order that the virgin queen of each colony would cross with males of this region. Ten days after the nine hives (one was lost) were brought back to Ribeirão Preto. No one of them produced diploid males. New samples took from all the Meliponary revealed that the number of xo sex alleles to have increased to 17,3. Than, this methodology can be used to increase the genetic variability of the stingless bees populations.

Them aim scope of this study is to characterize the enzymatic polymorphism found in the Melipona quadrifasciata Lepeletier, 1936 populations from Ribeirão Preto, São Paulo and Espírito Santo, Brazil and its hybrids. Samples from each colony (about 52) were prepared for starch gel electrophoresis in order to investigate the genetic variation of the following enzimes: esterase (EST), isocitrate dehydrogenase (IDH), malic enzyme (ME), phosphoglucomutase (PGM), superoxide desmutase (SOD), α-glycerophosphate dehydrogenase (αPGD), malate dehydrogenase (MDH), leucine aminopeptidase (LAP), hexokinase (HK) and phosphoglucose isomerase (PGI). The analysis showed that LAP and HK did not show enzymatic activity and EST showed two alleles(est-sand and est-f) while all the others were shown to be monomorphic. The allele EST-S showed a frequency of 82,6%.

Three methods of division of Melipona quadrifasciata Lep. colonies were evaluated: fisogastric queen naturally mated; orphans colonies, and queen mated in laboratory. Out of six colonies, five had grade 7 in 221 days, reaching 83,3% of success, in the 1st method. Out of four, 100% were formed using the 2nd method, in 221 days, and 71,4% out of seven colonies were formed with grade 7 in 195 days using the 3rd method. All colonies were treated with Syrup-A; the same management and same system of evaluation. Colonies obtained were described performance by the following mathematic models: Grade1 = 1.202 + 0.262 x reading; Grade2 = 1.474 + 0.250 x reading and Grade3 = 1.406 + 0.287 x reading. The 3rd method was the best considering time of the colonies development; however, it consumed more labor and laboratory equipments.