No abstract

Symbiotic interactions between microorganisms and social insects have been described as crucial for the maintenance of these multitrophic systems, as observed for the stingless beeScaptotrigona depilisand the yeastZygosaccharomycessp. The larvae ofS. depilisingest fungal filaments ofZygosaccharomycessp. to obtain ergosterol, which is the precursor for the biosynthesis of ecdysteroids that modulate insect metamorphosis. In this work we verified that nutritional fungal symbioses also occur in other species of stingless bees. We analyzed brood cell samples from 19 species of stingless bees collected in Brazil. The osmophilic yeast Zygosaccharomyces spp. was isolated from eight bee species, namelyScaptotrigona bipuctata,S. postica,S. tubiba,Tetragona clavipes,Melipona quadrifasciata,M. fasciculata,M. bicolorandPartamona helleri. These yeasts form pseudohyphae and also accumulate ergosterol in lipid droplets, similar to the pattern observed forS. depilis. The phylogenetic analyses including variousZygosaccharomycesrevealed that strains isolated from the brood cells formed a branch separated from the previously describedZygosaccharomycesspecies, suggesting that they are new species of this genus and reinforcing the symbiotic interaction with the host insects.

Symbiotic interactions between microorganisms and social insects have been described as crucial for the maintenance of these multitrophic systems, as observed for the stingless bee Scaptotrigona depilis and the yeast Zygosaccharomyces sp. SDBC30G1. The larvae of S. depilis ingest fungal filaments of Zygosaccharomyces sp. SDBC30G1 to obtain ergosterol, which is the precursor for the biosynthesis of ecdysteroids that modulate insect metamorphosis. In this work, we find a similar insect-microbe interaction in other species of stingless bees. We analyzed brood cell samples from 19 species of stingless bees collected in Brazil. The osmophilic yeast Zygosaccharomyces spp. was isolated from eight bee species, namely Scaptotrigona bipunctata, S. postica, S. tubiba, Tetragona clavipes, Melipona quadrifasciata, M. fasciculata, M. bicolor, and Partamona helleri. These yeasts form pseudohyphae and also accumulate ergosterol in lipid droplets, similar to the pattern observed for S. depilis. The phylogenetic analyses including various Zygosaccharomyces revealed that strains isolated from the brood cells formed a branch separated from the previously described Zygosaccharomyces species, suggesting that they are new species of this genus and reinforcing the symbiotic interaction with the host insects.

CASTRO, I. Artificial obtainment of queens and establishment of new colonies of Tetragona clavipes (Hymenoptera, Apidae, Meliponini). 2012. 99 p. Master's

Tetragona Lepeletier & Serville, 1828 (Hymenoptera: Apidae) is a genus of stingless bees widely distributed in Brazil. It has 15 species distributed in the Neotropics, from Mexico to Uruguay, nine of which are found in Brazil. However, Tetragona elongata (Lepeletier & Serville, 1828), a species known only from the Southeast region and which had been synonymized with Tetragona clavipes (Fabricius, 1804), was revalidated without any justification. The aim of this study was to test whether the morphometrics analysis of the wings is efficient in the diagnosis of the species of this genus, in addition to testing the validity of the revalidation mentioned above. This technique was applied by accessing the right forewings of 660 workers of T. clavipes, T. elongata e T. quadrangula (Lepeletier, 1836), from five Brazilian collections. For the geometric morphometric analysis, 12 landmarks were selected. The software MorphoJ version 1.6 was used to do Discriminant Function analysis (1000 replications) and Canonical Variation Analysis (CVA). Between T. clavipes and T. elongata, there was a 100% variance between species (canonical variation analysis), suggesting that it may be an indication of speciation. Even though T. elongata has been revalidated, it still has overlapped with T. clavipes, which indicates to be the same species. Taxonomic studies are needed to synonymize them.