Broad Protein Spectrum in Stored Pollen of Three Stingless Bees from the Chaco Dry Forest in South America (Hymenoptera, Apidae, Meliponini) and Its Ecological Implications

Favio Gerardo Vossler

doi:10.1155/2015/659538

Abstract

Protein content of pollen stored by three meliponine species was variable from 9.78% (less than half the value considered as optimal to brood development inApis mellifera) in typeCapparis tweediana-C. speciosato more than 26% in typeMaytenus vitis-idaeaand someProsopissamples. This pollen of low protein value was occasionally foraged (only six out of 75 masses analyzed ofG. argentina, but none in 86 masses ofT. fiebrigior in ten ofM. orbignyi). However, it is likely that amino acid deficiencies of certain pollens are compensated by randomly foraging on a broad spectrum of pollen plants. The large amounts of pollen stored in their nests might also be important in compensating these deficiencies. The only sample studied forM. orbignyishowed a protein value greater than the one required forA. melliferaand was dominated by typesAcacia praecoxandProsopis. As this species also prefersSolanumand other protein-rich pollen, more samples would need to be analyzed to establish whether protein requirements are high for thisMeliponaspecies. Pollen showing the highest protein content (>26%) belonged to highly nectariferous plants well represented in meliponine andApishoney such asProsopis,Maytenus, andZiziphus.

Highlights

The stingless bees (Apidae: Meliponini) are eusocial and they build perennial nests with hundreds to thousands of individuals and high reproductive rate [1, 2]
If protein content of pollen grains was constant for all individuals of each plant species, samples composed only or mostly of one pollen type (96–100%) (6 samples in the present study) would indicate their real protein value and it would be useful for comparing samples composed of many pollen types
The two samples dominated by type Maytenus vitis-idaea had high protein values (26.51 and 26.87%), followed by Castela coccinea that ranked near 20%, the minimum limit value considered as optimal to brood development in Apis mellifera L. [17], and the palm tree Trithrinax schizophylla with slightly less than 20%

Summary

Introduction

The stingless bees (Apidae: Meliponini) are eusocial and they build perennial nests with hundreds to thousands of individuals and high reproductive rate [1, 2]. To maintain their colonies, high amounts of pollen and nectar are foraged from flowers, the former stored as pollen masses and the latter as honey in pots made of cerumen. Exceptional protein resources such as soybean bran in Geotrigona mombuca (Smith) (sub G. inusitata in [11]) and flesh of dead animals in many Trigona, Partamona, Oxytrigona, Cephalotrigona, and others [12] can be facultatively gathered, pollen is the main protein source in bees. Ample protein content promotes a high birth rate and long-lived bees, 20% being the minimum protein

Objectives

Methods

Results

Conclusion