Suchergebnisse

Nannotrigona testaceicornis (Lepeletier, 1836) is a stingless bee with wide distribution in the Brazilian territory. Despite its importance in meliponiculture and pollination, there are still few behavioral studies related to the species. The aim of this work was to characterize the recognition and defense behaviors in intraspecific bioassays carried out in N. testaceicornis colonies. Intra and inter-colonial bioassays were carried out with six colonies from different locations. The number of occurrences of each behavioral act, latency measures, and duration of confrontations were quantified. An ethogram with eight behavioral acts and two categories was elaborated. The acceptance rate was significantly higher in intra-colonial confrontations and the rejection rate was higher in inter-colonial confrontations. The rejection process was significantly higher than the acceptance process, which may be related to the specific behavioral repertoire of each process. Results indicate that the presence of an intraspecific intruder triggers an aggressive response from guards positioned in the colony access tube.

Cytogenetic studies in Melipona are scarce with only 24 species analyzed cytogenetically. Of these, six species had the rDNA sites physically mapped and characterized by Fluorescent in situ Hybridization (fish). The aim of this study was to perform karyotype analyzes on Melipona species from different regions of Brazil, with a greater sampling representative of the Amazonian fauna and using conventional, fluorochrome staining and FISH with heterologous rDNA probes. The predominant chromosome number was 2n = 18, however, the subspecies M. seminigra abunensis and M. s. pernigra showed 2n = 22 chromosomes. The karyotypes were symmetrical, however M. bicolor, M. quadrifasciata, M. flavolineata, M. fuscopilosa, M. nebulosa presented the first pair heteromorphic in length. CMA3+ blocks also exhibited heteromorphism of size and in almost all cases coincided with rDNA sites, except for M. crinita and M. nebulosa, which presented additional non-coincident CMA3+ blocks. The CMA/ rDNA sites were terminal and interstitial in species with high heterochromatic content, and pericentromeric in those species with low heterochromatic content. In addition to pointing out cytogenetic features of cytotaxonomic importance, the reorganization of the genome in Melipona is discussed.

The taxonomic status of Platythyrea is still confused because there is high phenotypic plasticity, possible taxonomic synonyms and morphological proximity with other species of the same genus. The correct identification of Platythyrea sinuata depends on interdisciplinary analyzes with a morphological and genetic approach. Here we provide the description of karyotype for P. sinuata, 2k=24M+20A with CMA3+/DAPI- on single chromosome. This data will be helpful to the understanding of the taxonomic status of this species.