Division of Labor During Brood Production in Stingless Bees with Special Reference to Individual Participation Olga Inés Cepeda
Total Page：16
File Type：pdf, Size：1020Kb
Division of labor during brood production in stingless bees with special reference to individual participation Olga Inés Cepeda To cite this version: Olga Inés Cepeda. Division of labor during brood production in stingless bees with special reference to individual participation. Apidologie, Springer Verlag, 2006, 37 (2), pp.175-190. hal-00892200 HAL Id: hal-00892200 https://hal.archives-ouvertes.fr/hal-00892200 Submitted on 1 Jan 2006 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. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Apidologie 37 (2006) 175–190 175 c INRA/DIB-AGIB/ EDP Sciences, 2006 DOI: 10.1051/apido:2006018 Review article Division of labor during brood production in stingless bees with special reference to individual participation Olga Inés C Columbia Basin College, Science and Math Department, Pasco, WA 99301, USA Received 31 October 2005 – revised 26 January 2006 – accepted 15 February 2006 Abstract – The focus of this paper is the process for brood production known as the Provisioning and Oviposition Process (POP), and particularly the individual behavior observed in the facultatively polygy- nous stingless bee Melipona bicolor. Following individually marked bees revealed that ovarian development is correlated with individual behavior differences. While most of the eggs laid by workers are consumed by the queen (trophic eggs), workers contribute significantly in male production with reproductive eggs, illustrating the reproductive conflict at the individual level. From an evolutionary outlook, “benefactor” behaviors may evolve if workers conserve the “hope” of reproduction. This indicates that an important function of trophic eggs is to keep the ovaries active. It is also possible that ovary development represents an internal factor promoting division of labor: reproductive workers are specialized or elite bees with low response thresholds and high activity levels that restrain the participation of other workers. stingless bees / division of labor / POP / Melipona bicolor / reproductive competition / Apidae 1. DIVISION OF LABOR and guard duty at the entrance of the nest; (4) IN STINGLESS BEES foraging for pollen, nectar, propolis and other materials (Wille, 1983). Meliponine workers It has long been acknowledged that divi- exhibit considerable flexibility in task allo- sion of labor among hymenopteran workers cation: tasks are not rigidly established but presents age-correlated patterns of task per- depend on the conditions of the colony. For ex- formance (temporal polyethism) that spatially ample it is possible to force a colony consist- follow a centrifugal sequence (Wilson, 1985). ing only of old workers to rear brood by par- In stingless bees, very young bees produce tially re-activating the hypopharyngeal glands wax and work in the brood nest where they (Sakagami, 1982). were born. They move further away from it as they age until they leave the nest to be- come foragers. Although the age ranges dur- 2. DIVERSE APPROACHES TO THE ing which particular tasks are executed vary STUDY OF DIVISION OF LABOR across species, bees generally pass through four stages: callow, nurse bee, housekeeper and forager. The tasks associated with these Classic works representing purely etho- stages are: (1) incubation and repairs of the logical descriptions on division of labor in brood chamber; (2) construction and provi- meliponines date back to 1955. Since then, a sioning of cells, cleaning of the nest, and feed- multitude of studies have addressed general ing young adults and the queen; (3) further aspects of division of labor, the provisioning cleaning of the nest, reconstruction of the in- and oviposition process (POP), conflict be- volucrum, reception and ripening of nectar, tween colony members, evolution of behav- ior, taxonomical comparisons, and systemat- Corresponding author: [email protected] ics versus behavior (Online supplementary list Article published by EDP Sciences and available at http://www.edpsciences.org/apido or http://dx.doi.org/10.1051/apido:2006018 176 O.I. Cepeda of references1). However, few focused on spe- This concept generates a simple but powerful cialization and individual behavior. feedback system that distributes the appropri- Although in many of the studies bees were ate number of workers for each task, in a self- individually marked, results were presented organized manner. For social insects there ex- for age groups providing a general pattern ist empirical evidences supporting such mod- and thus lacking information on individual els (Robinson, 1992; Bonabeau and Theraulaz, differences in behavior. Individual differenti- 1999; Beshers and Fewell, 2001). Thresholds ation has been studied in other Hymenoptera, can be fixed when they do not change with age, e.g. in ants (Gordon, 1999), wasps (O’Donnell may be reinforced by repetition, or may be and Jeanne, 1990) and in Apis bees (Visscher “forgotten” if not performed (Bonabeau et al., and Camazine, 1999). In stingless bees, in- 1996). Literature also presents empirical evi- tranidal individual behavior has been studied dence in favor of the existence of reinforce- in Melipona favosa (Sommeijer et al., 1982; ment thresholds in social insects (Theraulaz Kolmes and Sommeijer, 1992), M. bicolor et al., 1991; O’Donnell, 1998; Robson and (Bego, 1983), Trigona (Tetragonula) minangk- Traniello, 1999). In stingless bees, indirect ev- abau (Inoue et al., 1996), and M. subnitida idence for response thresholds in M. bicolor is (Koedam et al., 1999). As for extranidal tasks, found in the pioneering work of Bego (1983). some works that addressed individual differen- She perceived that each individual carries out tiation related to food and resin collection has different percentages of the tasks and never been described in M. beecheii (Biesmeijer and the total repertoire of the colony. She verified Tóth, 1998), and concerning task partitioning that, on average, an individual carries out 50% in nectar collection, there is information com- to 70% of the total number of tasks. This re- piled for five species of stingless bees (Hart search demonstrates worker heterogeneity in and Ratnieks, 2002). stingless bees. Recent models of colony organization are Among a group of workers available for interested in how mechanisms at the individ- the execution of a task "x," some individuals ual level generate organization and behavior may present a high preference for such task at the colonial level. It is now recognized and dedicate themselves more frequently when that the genotype of a colony is distributed compared with the average task performance among hundreds or thousand of genetically di- frequency of other workers of the same age. verse individuals. In computer simulations, di- These workers are called specialists or elite vision of labor emerges by introducing min- (Robson and Traniello, 1999). There is em- imal variances in the responses of individuals pirical evidence in favor of the existence of to a task; such results may indicate that organi- specialization in Hymenoptera (Rissing, 1981; zation in a colony emerges as a self-organized Calderone and Page, 1988; O’Donnell and system derived from the independent actions Jeanne, 1990). Kolmes and Sommeijer (1992), of workers (Ronacher and Wehner, 1999). In working with the stingless bee M. favosa, order to clarify the mechanisms that gener- found that the construction of brood cells is ate colonial organization and behavior, mod- a task performed by an elite group of work- els based on proximal mechanisms that incor- ers. Inoue et al. (1996) presented evidence porate both internal and external factors have on individual variation between workers for been developed (Beshers and Fewell, 2001). the bee Trigona (Tetragonula) minangkabau. The response threshold model refers to inter- They verified that the population of a nest can nal individual limits that regulate individual be divided into two main groups: nurse bees responses to diverse tasks. Such a model as- that can spend all their lives taking care of the sumes that response thresholds are specific for brood, and foragers that hardly or never work each task and that each individual can have on the comb. Here we see evidence for strong adifferent threshold for each task (Beshers and very limited response thresholds leading et al., 1999; Bonabeau and Theraulaz, 1999). to extreme specializations. Finally, individual behavior must be inte- 1 Available at: http://www.edpsciences.org grated with colonial organization. The model Division of labor in stingless bees 177 of social inhibition explains that temporary for the diverse repertories were established polyethism is the result of the interaction of (Sakagami and Zucchi, 1966). Comparisons an intrinsic process of behavioral development of the POP in different species have been with an inhibiting effect produced by other used to establish relations between systemat- workers (Huang and Robinson, 1999). This ics and behavior (Sakagami and Zucchi, 1966; model combines the physiological state in re- Drummond et al., 2000) and phylogenetic re- lation to the task together with the external