Histological survey of protocerebral areas and retrocerebral complex of Melipona quadrifasciata anthidioides workers (Hymenoptera, Apidae, Meliponini)

Author(s)

Cintia Etsuko Yamashita

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB)
• Defense date: 2009-04-13

Examining board members

Mirian David Marques; Maria Cristina Arias; Alcira Tania Bijovsky de Katzin

• Advisor: Mirian David Marques

Abstract

The stingless bees colony comprises a queen, workers of diferent ages that perform different tasks and males only present before the queen´s fecundation. Among the workers, only the oldest ones foragers keep a direct contact with the light/dark environmental cycle. Biological rhythms are present and are generated by the circadian system located in the central nervous system and in the retrocerebral complex. This system is composed by a web of multiple oscillators coupled to input pathways from the sensorial system and output pathways. The output pathways consist in nervous, neurohormones and hormones components. In this study, the central nervous system and the retrocerebral complex of Melipona quadrifasciata foragers were analyzed by classical histological procedures complemented by immunocitochemical essays. Specific reactive antibodies against Fasciclin II, PDF and Corazonin have been used. The optic lobes neuropils: lamina, medulla and lobula are distinct and evident. The protocerebrum is the dorsal most and largest ganglia. In this structure two neuropilar groups are present: corpora pedunculata, the bilateral mushroom bodies that occupy a large portion of the protocerebrum; and the central complex in the median line. Neurosecretory cells cluster together in two protocerebral regions: pars intercerebralis and pars lateralis. The retrocerebral complex is composed by two pairs of glands: corpora cardiaca and corpora allata. In this work, tridimensional images show their specific localization in the nervous system. In both, central nervous system and retrocerebral complex of M. quadrifasciata, species specific traces can be recognized in morphological characteristics and spatial localization of certain structures. The results on the anatomy of stingless bees nervous system shown here are indispensable to proceed with studies that aim to identify the components and the organization of the circadian system of stingless bees. (AU)