Abelhas Melipona: fungos cultiváveis do alimento larval e sua participação na destinação das castas

Abstract

The Amazonian bee Melipona interrupta from the tribe Meliponini holds a prominent role in the ecosystem as a pollinator and honey producer, being associated with a wide range of microorganisms, as the hives provide suitable microenvironments for their full development. This research investigated the presence and identified, morphologically and molecularly, the most frequently isolated cultivable fungi from the larval food of natural brood cells and tested their influence on queen production after inoculation into the larval food in artificial brood cells of Melipona (Melikerria) interrupta Latreille, 1811. To achieve this, 1656 natural brood cells were daily monitored, through visual detection and under a stereomicroscope, regarding the complete development of the immatures and caste segregation, which demonstrated a massive queen production in all months of the year, however, without exceeding the expected genetic limit of 25%. The presence of fungal mycelium was observed on the food content in all brood cells, which are consumed by the developing immatures. Through decimal serial dilution of the larval content from natural brood cells with 1, 8, and 15 days after queen oviposition, fungi isolation was performed, establishing the frequencies of Colony-Forming Units. Based on morphological analysis of 10 fungal morphotypes, it was possible to distinguish four genera, with Oidiodendron sp. and Cladosporium sp. being less frequent, and another two more frequent genera confirmed by molecular identification of sequences from the ITS1-5.8S-ITS2 of rDNA and D1/D2 26S of rRNA, Fomitopsis sp. (FAB = 95; FRE% = 58) and Zygosaccharomyces sp. (FAB = 35; FRE% = 21), whose sequences confirmed phylogenetic proximity with sequences of these taxa available in databases. The most frequent fungi were inoculated into the larval food of 360 larvae, under artificial breeding conditions, generating an expected segregation of up to 25%, proving to be important food sources for the larvae and their survival. Especially, Zygosaccharomyces sp. proved to be valuable for the viability of larval development, reducing mortality and producing queens at levels equivalent to natural conditions.