Morphometric differences and fluctuating asymmetry in Melipona subnitida Ducke 1910 (Hymenoptera: Apidae) in different types of housing.

C B S Lima,B A Souza,M F Ribeiro,L A Nunes,C A L Carvalho,C S B Silva

doi:10.1590/1519-6984.01015

Abstract

A geometric morphometrics approach was applied to evaluate differences in forewing patterns of the Jandaira bee (Melipona subnitida Ducke). For this, we studied the presence of fluctuating asymmetry (FA) in forewing shape and size of colonies kept in either rational hive boxes or natural tree trunks. We detected significant FA for wing size as well as wing shape independent of the type of housing (rational box or tree trunks), indicating the overall presence of stress during the development of the studied specimens. FA was also significant (p < 0.01) between rational boxes, possibly related to the use of various models of rational boxes used for keeping stingless bees. In addition, a Principal Component Analysis indicated morphometric variation between bee colonies kept in either rational hive boxes or in tree trunks, that may be related to the different origins of the bees: tree trunk colonies were relocated natural colonies while rational box colonies originated from multiplying other colonies. We conclude that adequate measures should be taken to reduce the amount of stress during bee handling by using standard models of rational boxes that cause the least disruption.

Highlights

Melipona subnitida occurs naturally in the savannah region of north-eastern Brazil
Given the need for information about the effect of stress on stingless bee colonies, the present study aims to examine fluctuating asymmetry based on the variation in wing shape and wing size in individuals of M. subnitida kept in either rational boxes or trunks
The significant interaction of individual X side suggest that stress levels caused by environmental factors such as minimal variations in temperature, sunlight, and scarcity of food resources (Ricklefs, 2009) may directly influence wing size and wing shape of the bees, regardless of their housing conditions

Summary

Introduction

Melipona subnitida occurs naturally in the savannah region of north-eastern Brazil. Commonly used for beekeeping, rational hive boxes are advantageous for bee handling and high yields of honey and other products (Bruening, 2001; Cortopassi-Laurino and Imperatriz-Fonseca, 2001; Lopes et al, 2007; Camargo and Pedro, 2013). Bees experience stress during and after the transfer of colonies to rational boxes especially when opening the tree trunk for nest removal, an aggressive procedure likely to cause breakage of food pots and crushing of young worker bees (Nogueira-Neto, 1997). According to this author, stress to the bees is caused by the process of honey collection itself: opening the box creates an excess of moisture that interferes with offspring development, produces an imbalance in thermoregulation of the colony and promotes a suitable environment for fungi, among other damages. Given the need for information about the effect of stress on stingless bee colonies, the present study aims to examine fluctuating asymmetry based on the variation in wing shape and wing size in individuals of M. subnitida kept in either rational boxes or trunks

Study area

Image acquisition

Data analysis

Results

Discussion