Miniature queens in stingless bees: basic facts and evolutionary hypotheses

Abstract

-Some stingless bees are known to produce both large queens, reared from larger royal cells, and small "miniature" queens, reared from worker cells. Here we review what is known about miniature queens, and evaluate some major evolutionary hypotheses as to why they are produced. One hypothesis -that miniature queens are females who selfishly evade an intended worker fate -is shown to receive significant support. In particular, there is increasing evidence that the decision to become a miniature queen may be under genetic control of the developing females themselves. In addition, data from several species show that females gain significant fitness benefits from doing so, since miniature queens are frequently observed heading colonies and often are as productive as normal-sized queens. On the other hand, in some species miniature queens have a reduced fecundity or may have lower chances of being chosen as a new queen. This shows that the strategy may also have costs. Queens of the genus Melipona, which are also reared from worker-sized cells, are suggested to have the same evolutionary origins as miniature queens. queen dimorphism / miniature queens / stingless bees / caste fate conflict / Apidae / Meliponini

Altruism in insect societies and beyond: voluntary or enforced?

“…There is good evidence for such evasion (Figure 4). For example, in trigonine stingless bees, queens are normally reared in larger cells, but in several species females in worker cells evade an intended worker fate by developing as miniature queens [25]. These dwarf queens can successfully head colonies but appear to be under-represented.…”

The evolution of extreme altruism and inequality in insect societies

“…Dwarf queens in trigonine stingless bees develop in a worker cell. Honeybee workers may lay eggs that evade worker policing, or enter a nearby queenless colony in which worker policing has been switched off , Ribeiro et al (2006) must consider interactions with other conflicts worker policing of worker-laid eggs can be selected for on sex allocation grounds. This may account for the occurrence of worker policing in species with queens mated to a single male Foster & Ratnieks (2001b) must consider also benefits and costs policing on colony efficiency grounds.…”

Interaction and behavior of virgin and physogastric queens in three Meliponini species (Hymenoptera, Apidae)

“…This has been reported for colonies of Cephalotrigona capitata (Ihering, 1903), Plebeia juliani (Juliani, 1962;Imperatriz-Fonseca and Zuchi, 1995), Plebeia remota (Ribeiro et al, 2006), Nannotrigona testaceicornis (Imperatriz-Fonseca et al, 1997) and Schwarziana quadripunctata (Camargo, 1974;Imperatriz-Fonseca and Darakjian, 1993;Nogueira-Ferreira et al, 2000;Ribeiro and Alves, 2001;Wenseleers et al, 2005). Ribeiro et al (2006) revised the existing information about production of miniature queens; they hypothesized that miniature queens are females who selfishly evade an intended worker's fate.…”

“…The miniature queens can lay fertile eggs; though their eggs are smaller than those of the normal-sized queens they can head colonies (Castilho-Hyodo, 2001). However, they lay fewer eggs than normal-size queens (Ribeiro and Alves, 2001;Wenseleers et al, 2005;Ribeiro et al, 2006).…”