Colony multiplication of the neotropical stingless bee Tetragonisca angustula started with the finding of a new nesting site by scout bees, followed by the cleaning of the cavity. Cerumen was flown in from the mother colony for the sealing of crevices and the construction of an entrance tube. Major investment of the mother colony in the daughter nest was in workers and cerumen. Almost negligible amounts of pollen were transported from the mother colony after arrival of the gyne in the founding colony. Small quantities of honey were transferred as well. Workers from the daughter nest foraged actively for pollen. Some 500 to 1000 workers entered in the daughter nest, following the virgin queen. This is only a relatively small proportion of the population of the mother colony. Two to four days after the nuptial flight the young queen started egg-laying, and storage pots, mainly filled with honey and some pollen were encountered. In the mother nest, ample pollen and honey stores were present during the months preceding the swarming process. Shortly before swarming took place brood (and adult) populations were 20 to 50% higher than in the other non-swarming colonies, whereas the production of royal cells and males was not different. Data were compared with those got in literature.

Since its first contact with Apis mellifera, the population dynamics of the parasitic mite Varroa destructor varies from one region to another. In many regions of the world, apiculture has come to depend on the use of acaricides, because of the extensive damage caused by varroa to bee colonies. At present, the mite is considered to contribute to the recent decline of honey bee colonies in North America and Europe. Because in tropical climates worker brood rearing and varroa reproduction occurs all year round, it could be expected that here the impact of the parasite will be even more devastating. Yet, this has not been the case in tropical areas of South America. In Brazil, varroa was introduced more than 30 years ago and got established at low levels of infestation, without causing apparent damage to apiculture with Africanized honey bees (AHB). The tolerance of AHB to varroa is apparently attributable, at least in part, to resistance in the bees. The low fertility of this parasite in Africanized worker brood and the grooming and hygienic behavior of the bees are referred as important factors in keeping mite infestation low in the colonies. It has also been suggested that the type of mite influences the level of tolerance in a honey bee population. The Korea haplotype is predominant in unbalanced host-parasite systems, as exist in Europe, whereas in stable systems, as in Brazil, the Japan haplotype used to predominate. However, the patterns of varroa genetic variation have changed in Brazil. All recently sampled mites were of the Korea haplotype, regardless whether the mites had reproduced or not. The fertile mites on AHB in Brazil significantly increased from 56% in the 1980s to 86% in recent years. Nevertheless, despite the increased fertility, no increase in mite infestation rates in the colonies has been detected so far. A comprehensive literature review of varroa reproduction data, focusing on fertility and production of viable female mites, was conducted to provide insight into the Africanized bee host-parasite relationship.

The behaviour of drones of different species of Melipona was studied in Costa Rica and on Tobago. Drones of all species behaved very similarly. The intranidal behavioural analysis indicates that drones spent most time on standing, walking, stirring the antennae and self-grooming. The only "typical worker behaviour", occasionally performed by 16 to 18 days old drones of Melipona, was the participation in nectar dehydrating. The age-relatedness and location in the nest where a behaviour is performed is being discussed. Worker aggression against drones was observed only three times. The behaviour of drones when they leave the nest is described. Drones leave the nest mainly between 8 and 11 AM, at an average age of 18.6 days. It was observed that drones do not return after they have once left the hive.A description is given of a nest-associated drone aggregation of Melipona fasciata on a wall. Drones of this species stayed in the aggregation for an average of 7.6 days, spending most time on standing or flying in a "cloud" near the nest entrance. They spent about five hours daily on the average and may leave the aggregation temporary. Drones were able to live up to 74 days in a closed hive, the average being 45 days.Implications of drone behaviour for the mating biology of stingless bees are discussed.

Reproductive division of labor in advanced eusocial honey bees and stingless bees is based on the ability of totipotent female larvae to develop into either workers or queens. In nearly all species, caste is determined by larval nutrition. However, the mechanism that triggers queen development in Melipona bees is still unresolved. Several hypotheses have been proposed, ranging from the proximate (a genetic determination of caste development) to the ultimate (a model in which larvae have complete control over their own caste fate). Here, we showed that the addition of geraniol, the main compound in labial gland secretions of nurse workers, to the larval food significantly increases the number of larvae that develop into queens. Interestingly, the proportion of queens in treated brood exactly matched the value (25%) predicted by the twolocus, two-allele model of genetic queen determination, in which only females that are heterozygous at both loci are capable of developing into queens. We conclude that labial gland secretions, added to the food of some cells by nurse bees, trigger queen development, provided that the larvae are genetically predisposed towards this developmental pathway. In Melipona beecheii, geraniol acts as a primer pheromone representing the first caste determination substance identified to date.

The behaviour of gynes of Melipona beecheii in queen-deprived colonies was studied. The period after emergence until acceptance is characterized by agonistic behaviour of workers towards the gynes. The gynes escaped from this worker aggression by hiding in the periphery of the nest, by performing rapid turn-arounds once grabbed by a worker, and "feigning death". Between acceptance and nuptial flight, gynes spent most of their time in pushing, hiding, and antennal contact with workers, and self-grooming or food solicitation. After the nuptial flight the queen's behavioural repertoire shifted to less pushing and food solicitation, to an increase in standing, tapping and antennal contact.Accepted gynes had a significantly more prolonged abdomen inflation than gynes that were eliminated.An hypothesis is presented to explain how abdomen enlargement and behavioural development influences the acceptance of gynes and the establishment of a dominance relation with workers under queenless conditions.

-Stingless bees produce considerable numbers of virgin queens over the year, most of which are superfluous and get executed by the workers. Nothing is known yet about the sign stimulus that releases the worker attacks. In the present study we investigated the queen execution process in Melipona beecheii and found in both behavioral observations and experiments with caged living virgin queens that workers are not attracted to them from a distance by means of volatile chemicals. Furthermore, worker aggression, which is obvious towards virgin queens that run through the nest excitedly with their abdomen enlarged and the wings beating, was lowered to almost zero when we made the queens "behavior-less" by experimentally killing them. Our results clearly show that the sign stimulus for releasing the execution behavior in Melipona beecheii workers is not a chemical stimulus but the virgin queens' conspicuous behavior, which, we hypothesize, could act as a direct measure of their fitness. stingless bee / Melipona beecheii / virgin queen execution / queen behavior / worker attacks

Colony infestation by the parasitic mite, Varroa destructor is one of the most serious problems for beekeeping worldwide. In order to reproduce varroa females, enter worker or drone brood shortly before the cell is sealed. To test the hypothesis that, due to the preference of mites to invade drone brood to reproduce, a high proportion of the mite reproduction should occur in drone cells, a comparative study of mite reproductive rate in worker and drone brood of Africanized honey bees (AHB) was done for 370 mites. After determining the number, developmental stage and sex of the offspring in worker cells, the foundress female mite was immediately transferred into an uninfested drone cell. Mite fertility in single infested worker and drone brood cells was 76.5 and 79.3%, respectively. There was no difference between the groups (X(2)= 0.78, P = 0.37). However, one of the most significant differences in mite reproduction was the higher percentage of mites producing viable offspring (cells that contain one live adult male and at least one adult female mite) in drone cells (38.1%) compared to worker cells (13.8%) (X(2)= 55.4, P < 0.01). Furthermore, a high level of immature offspring occurred in worker cells and not in drone cells (X(2)= 69, P < 0.01). Although no differences were found in the percentage of non-reproducing mites, more than 74% (n = 85) of the mites that did not reproduce in worker brood, produced offspring when they were transferred to drone brood.

3 and 8 days old when they undertake the nuptial flight [12,16], although in one case a 17 hours old gyne flew out on a nuptial flight and mated successfully [16]. In confinement, gynes of M. quadrifasciata were able to mate on the day of emergence [2]. Based on sperm counts of open mated queens of M. quadrifasciata compared with INTRODUCTIONThe complete mating flight of any stingless bee has not been observed so far. The mating flight is undertaken from the mother colony in case of supersedure and from the filial nest in case of swarming. For Meliponini it is known that gynes are between Original articleObservations on gynes and drones around nuptial flights in the stingless bees Tetragonisca angustula and Melipona beecheii (Hymenoptera, Apidae, Meliponinae)Johan Wilhelm VAN