Soldiers in a Stingless Bee: Work Rate and Task Repertoire Suggest They Are an Elite Force

Author(s)

Hammel, Benedikt ^{[1, 2]} ; Vollet-Neto, Ayrton ^[1] ; Menezes, Cristiano ^[3] ; Nascimento, Fabio S. ^[1] ; Engels, Wolf ^{[1, 2]} ; Grueter, Christoph ^{[4, 1]}

Affiliation

^[1] Univ Sao Paulo, Dept Biol, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14040901 Ribeirao Preto, SP - Brazil

^[2] Univ Tubingen, Inst Evolut & Ecol, D-72076 Tubingen - Germany

^[3] Embrapa Amazonia Oriental, BR-66017970 Belem, Para - Brazil

^[4] Univ Lausanne, Dept Ecol & Evolut, Biophore, CH-1015 Lausanne - Switzerland

• Document type: Journal article
• Source: American Naturalist; v. 187, n. 1, p. 120-129, JAN 2016.
• Web of Science Citations: 11

Abstract

The differentiation of workers into morphological subcastes (e.g., soldiers) represents an important evolutionary transition and is thought to improve division of labor in social insects. Soldiers occur in many ant and termite species, where they make up a small proportion of the workforce. A common assumption of worker caste evolution is that soldiers are behavioral specialists. Here, we report the first test of the ``rare specialist{''} hypothesis in a eusocial bee. Colonies of the stingless bee Tetragonisca angustula are defended by a small group of morphologically differentiated soldiers. Contrary to the rare specialist hypothesis, we found that soldiers worked more (+34%-41%) and performed a greater variety of tasks (+23%-34%) than other workers, particularly early in life. Our results suggest a ``rare elite{''} function of soldiers in T. angustula, that is, that they perform a disproportionately large amount of the work. Division of labor was based on a combination of temporal and physical castes, but soldiers transitioned faster from one task to the next. We discuss why the rare specialist assumption might not hold in species with a moderate degree of worker differentiation. (AU)

• FAPESP's process: 12/11144-0 - Evolution of mating systems in stingless bees (Apidae, Meliponini)
• Grantee: Ayrton Vollet Neto
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 10/10027-5 - Behavioural mediation, chemical signalisation and physiological aspects regulating the social organization in hymenopterans
• Grantee: Fábio Santos do Nascimento
• Support Opportunities: Research Grants - Young Investigators Grants