Age polyethism in Plebeia emerina (Friese) (Hymenoptera: Apidae) colonies related to propolis handling

Abstract

-Stingless bees collect plant resins and make it into propolis, although they have a wider range of use for this material than do honey bees (Apis spp.). Plebeia spp. workers employ propolis mixed with wax (cerumen) for constructing and sealing nest structures, while they use viscous (sticky) propolis for defense by applying it onto their enemies. Isolated viscous propolis deposits are permanently maintained at the interior of their colonies, as also seen in other Meliponini species. Newly-emerged Plebeia emerina (Friese) workers were observed stuck to and unable to escape these viscous propolis stores. We examined the division of labor involved in propolis manipulation, by observing marked bees of known age in four colonies of P. emerina from southern Brazil. Activities on brood combs, the nest involucrum and food pots were observed from the first day of life of the marked bees. However, work on viscous propolis deposits did not begin until the 13 th day of age and continued until the 56 th day (maximum lifespan in our sample). Although worker bees begin to manipulate cerumen early, they seem to be unable to handle viscous propolis till they become older.

Resin Use by Stingless Bees: A Review

“…For some species, these caches serve as temporary storage where resins accumulate until they can be incorporated into other nest structures or used for defensive purposes (e.g., Trigona (Trigona) p. pallens [52]; Tetragonisca angustula (Latreille) and Plebeia spp. [29,50]). Unlike most resin, which hardens upon contact with air, deposit-resins remain viscous for a prolonged period of time.…”

“…Alternatively, or additionally, the prolonged viscosity of deposit-resins could result from chemical processing. While definitive research on this topic is lacking, a comparative analysis of the morphology of head salivary glands and intramandibular glands of bees of various ages suggests that Plebeia emerina workers modify deposit-resins using secretions, which might help to maintain their viscosity [50].…”

“…It is possible that propolis produced by difference species and for different purposes could contain variable amounts of wax, and in some cases no wax at all, but this has yet to be verified. Deposit-resins, also referred to as resin deposits or viscous propolis deposits [10,49,50], are resin caches located on the nest floor or walls [51]. For some species, these caches serve as temporary storage where resins accumulate until they can be incorporated into other nest structures or used for defensive purposes (e.g., Trigona (Trigona) p. pallens [52]; Tetragonisca angustula (Latreille) and Plebeia spp.…”

“…Once resin foragers return to the hive, they unload resin from their corbiculae on their own, or with the help of another worker [50,55,88]. The often brightly colored resin loads are mixed with wax to form cerumen, or incorporated into other nest structures.…”

Age Polyethism in Atta sexdens (Linnaeus) (Hymenoptera: Formicidae)

“…This labor division is called age polyethism and corresponds to task switching according to individual age. Age polyethism is relatively common in social insects (Kolmes, 1986), including bees (Santos et al, 2010), termites (Yanagihara et al, 2018), and ants (Santana Vieira et al, 2010). Generally, younger individuals perform safer tasks inside the nest, while older workers perform riskier tasks outside, as the latter are "less valuable" to the colony (Santana Vieira et al, 2010).…”