Seasonal production and spatial distribution of Melipona bicolor schencki (Apidae; Meliponini) castes in brood combs in southern Brazil Ney Jr, Betina Blochtein, José Serrão To cite this version: Ney Jr, Betina Blochtein, José Serrão. Seasonal production and spatial distribution of Melipona bicolor schencki (Apidae; Meliponini) castes in brood combs in southern Brazil. Apidologie, Springer Verlag, 2013, 44 (2), pp.176-187. 10.1007/s13592-012-0169-2. hal-01201285 HAL Id: hal-01201285 https://hal.archives-ouvertes.fr/hal-01201285 Submitted on 17 Sep 2015 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. 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Apidologie (2013) 44:176–187 Original article * INRA, DIB and Springer-Verlag France, 2012 DOI: 10.1007/s13592-012-0169-2 Seasonal production and spatial distribution of Melipona bicolor schencki (Apidae; Meliponini) castes in brood combs in southern Brazil 1 1 2 Ney Telles FERREIRA JR , Betina BLOCHTEIN , José Eduardo SERRÃO 1Laboratório de Entomologia, Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul, 90619-900 Porto Alegre, RS, Brazil 2Departamento de Biologia Geral, Universidade Federal de Viçosa, 36570-000 Viçosa, MG, Brazil Received 23 May 2012 – Revised 3 September 2012 – Accepted 23 September 2012 Abstract – Melipona bicolor schencki is currently considered a threatened stingless bee in southern Brazil, and studies about its ecology may provide new insights to enable its conservation. This study evaluated the seasonal variability in the sex/caste proportion, numbers of combs and brood cells, and spatial distribution of the individuals present in emerging combs in five polygynous colonies of M. bicolor schencki for 1 year. Throughout the year, the colonies showed similar variations. Individual combs exhibited a higher number of brood cells in spring and summer, although there was no variation in the number of combs over the four seasons. Workers (79.7 %), queens (15.6 %), and drones (4.7 %) were produced in all months sampled. Analysis of spatial distribution indicated no clear predominance of a specific sex or caste in a specific comb area, contrary to other species of Melipona. Melipona / larvae / stingless bee / queen / male 1. INTRODUCTION 2003; Borges and Blochtein 2006), and food availability (Winston 2003). Stingless bees (Meliponini) are widespread in Thediameterofbroodcombsfrom tropical regions, predominantly in the subtrop- Meliponini can be used to calculate the number ics in the Southern Hemisphere (Michener of brood cells. Thus, intraspecific differences in 2000). Species of Melipona Illiger, 1806, as the production of brood cells can be determined, well as other genera of stingless bees, build which allows for the classification of colonies nests with horizontal brood combs (Michener from the same environment. Colonies can be 1974; Cepeda 2006; Roubik 2006), which have classified as weak, median, or strong for those offspring in different developmental stages with a few, intermediate, or high number of (Kerr et al. 2001). The production of brood brood cells, respectively (Kleinert-Giovannini combs by stingless bees may be affected by the and Imperatriz-Fonseca 1986; Hilário et al. available space inside the nests (Sakagami 2000;Kleinert2005; Fidalgo and Kleinert 1982), environmental conditions (Ribeiro et al. 2007). However, the seasonal variations in the number of brood cells in Meliponini nests are poorly studied (Pick and Blochtein 2002; Corresponding author: B. Blochtein, Borges and Blochtein 2006). [email protected]; J.E. Serrão, [email protected] In Melipona bicolor bicolor Lepeletier, 1836, Manuscript editor: James Nieh the production of brood cells was shown to be Seasonal production of castes in a stingless bee 177 higher at 30–32 °C than at lower temperatures 2003). In M. favosa, brood combs were found to (Velthuis et al. 1999). In southern Brazil, have 78.4 % workers, 5.1 % queens, and 17.3 % colonies of Melipona marginata obscurior males (Koedam 1999; Sommeijer et al. 2003). Moure, 1971, showed the highest number of Unlike other species of stingless bees that build combs and brood cells during the spring and brood cells for the production of queens in the summer (Borges and Blochtein 2006). In M. periphery of the brood combs (Nogueira-Neto bicolor, which has permanent polygynous col- 1997), in species of Melipona, the distribution of onies (Kerr 1949; Silva et al. 1972; Nogueira- brood cells for queens, workers, and males in the Neto 1997; Velthuis et al. 2001; Cepeda 2006), combs cannot be estimated because there is no the production of brood cells is also influenced apparent differentiation of size of the brood cells. by the number of physogastric queens (Velthuis However, in M. favosa, brood cells containing et al. 1999). queens are more frequently placed in the In contrast to other stingless bees, in the nests peripheral region of the comb, although they of Melipona species, queens, workers, and can also be found in the center, while males are males develop until the adult stage in brood predominantly displayed in the center of the cells of the same size (Kerr 1950; Kerr et al. comb (Koedam 1999). In M. subnitida, males are 1966; Engels and Imperatriz-Fonseca 1990; grouped in the central area of the combs Nogueira-Neto 1997; Roubik 2006; Menezes (Koedam et al. 1999). Similarly, in combs of et al. 2007). M. bicolor produces a similar M. beecheii, males are more often found in the number of queens and males, whereas Plebeia central and medium areas, whereas queens are remota (Holmberg 1903) and Schwarziana randomly distributed, and the workers are more quadripunctata (Lepeletier 1836), which are frequently at the edges of the comb (Moo-Valle monogynic species with brood cells for queen et al. 2004). production that are larger than those for pro- Melipona bicolor schencki Gribodo, 1893, is duction of males and workers, have a lower a stingless bee threatened in southern Brazil proportion of queens compared with males (Blochtein and Harter-Marques 2003; IBAMA (Santos-Filho et al. 2006). 2003). This study evaluated the seasonal brood Seasonal changes may affect the number of production, contributing to the management, queens, workers, and males in the colonies. and conservation of this bee. Melipona beecheii Bennett, 1831, produces a higher number of males in the spring, followed by a gradual decrease until summer. In 2. MATERIALS AND METHODS Melipona favosa (Fabricius 1798) colonies, the production of males increases in autumn (Van 2.1. Area Veen et al. 1997) or summer (Sommeijer et al. 2003). The population of queens in the combs The study was carried out at the Research and of M. favosa in field conditions was similar Nature Conservation Center Pró-Mata of PUCRS throughout the year (Sommeijer et al. 2003). ("Pro-Forest") (29°27’S/29°S, 50°08’W/50°15’W, In species of Melipona,theremaybe 900 m above sea level) in São Francisco de Paula, variation in the ratios of queens, males, and state of Rio Grande do Sul, Brazil, with predominant workers in the combs. In brood combs of vegetation of Araucaria Forest. The climate is humid Melipona subnitida Ducke 1910, the workers to super-humid, with 1,750–2,500 mm annual rainfall represent 91.8 % of the offspring, while queens (Bertoletti and Teixeira 1995). and males make up 6.96 % and 1.24 %, respectively (Koedam et al. 1999). In 2.2. Bee colonies Melipona trinitalis Cockerell 1919, the propor- tion of workers was shown to be 87.6 %, queens Five polygynous colonies (each with two phys- 4.8 %, and males 7.7 % (Sommeijer et al. ogastric queens) of M. bicolor schencki were kept in 178 N.T. Ferreira Jr et al. wooden boxes, with external sizes of 26×28×37 cm, The statistical similarity found allowed the clus- covered by transparent glass lids. Colonies were tering of the of the monthly data obtained from the maintained in a room at 25±2 °C. Each colony had five colonies as well as a clustering according the access to the external environment by means of a seasonal production (spring–summer and autumn– plastic tube (15 mm in diameter) that crossed the winter) of the number of combs and brood cells. The room wall. When necessary, colonies were fed on number of combs and brood cells in spring–summer 50 % sucrose solution (Nogueira-Neto 1997). and autumn–winter periods were compared by the Student’s t test at 5 % significance level. 2.3. Sampling of combs and seasonality 2.5. Seasonal quantification of workers, The wax covering the combs (involucrum) of each queens, and males in mature brood colony was removed to access the brood combs. The combs number of combs was counted monthly, and one mature brood comb was removed for analyses of The presence of workers, queens, and males in offspring. This procedure was performed monthly each comb was estimated from the percentage of from November, 2006 to October, 2007, and the individuals and the total number of brood cells per results were analyzed according to the four seasons. comb, for a total of 11,317 brood cells. The data set was submitted to the Kolmogorov–Smirnov test. To 2.4. Determination of the number evaluate the homogeneity and normal distribution and of workers, queens, and males because both conditions were not obtained, sex per in the brood combs caste per month dataset were showed as median, first and third quartiles, and standard error of the median. The quantities and spatial distribution of brood Otherwise the percentage of workers, queens, and cells containing workers, queens, and males were males per colony, along the entire period, had normal analyzed one comb removed from colony, according distribution and were submitted to the Tukey`s test at to the procedures described by Koedam (2003).