Heterochrony of cuticular differentiation in eusocial corbiculate bees

Abstract

-The exoskeleton (cuticle) of insects varies widely in shape, biomechanical properties, and functions, which are inherent to the biological species and developmental stage, besides showing a wealth of architectural specializations and nuances in the different body regions. The morphological pattern of exoskeleton maturation was studied in eusocial and solitary bees, including species of all three eusocial tribes of corbiculate bees as follows: Apini, Meliponini, and Bombini. The results showed striking differences in the rate of cuticle maturation between the solitary bees that leave the nest soon after the adult ecdysis, and the eusocial bees that take longer to leave the colony for foraging activities. There was a clear delay in the postecdysial cuticle tanning (melanization and sclerotization) in the eusocial bee species in comparison to the solitary species, suggesting adaptation to sociality and to the protective environment of the colony. Such heterochrony of cuticle maturation seems a conserved ontogenetic trait related to the way of life in corbiculate bees. The data generated a basic framework of exoskeleton maturation in corbiculate bees, under ontogenetic and evolutionary approaches, and give experimental support for further research on adaptation to the colony environment.exoskeleton / tanning / eusociality / Apinae / solitary bees

The relationship between queen execution and cuticular hydrocarbons in stingless bee Melipona scutellaris (Hymenoptera: Meliponini)

“…In the social insects, the cuticle is not yet mature after the last change. The body cuticle is completely mature only in older individuals and the more abundant CHs are alkanes, followed by alkenes, alkadienes, and methyl alkenes (Elias-Neto et al 2013;Falcon et al 2014;Kather and Martin 2015). Our findings for the CH profiles in M. scutellaris virgin queens show differences from those reported for this stingless bee by Kerr et al (2004), which were rich in tricosane contrasting with hentricontene as described here, which may be due to different CH extraction procedures, given that those authors only used the bee's wings.…”

Exploring integument transcriptomes, cuticle ultrastructure, and cuticular hydrocarbons profiles in eusocial and solitary bee species displaying heterochronic adult cuticle maturation

“…In this context, we draw our attention to the fact that bees greatly vary in the grade of cuticle melanization/sclerotization at the emergence time (adult ecdysis). In a previous study on the morphology of the developing adult cuticle [34], we observed that in eusocial bees, but not in the solitary ones, the process of cuticle melanization/sclerotization leading to cuticle maturation is extended to the adult stage. After emergence, workers from eusocial species (including the primitively eusocial bees from Bombini) spend some days performing inside nest activities, and during this period they stay protected in a safe and provisioned environment [35] where the hygienic behavior provides a certain level of immunity [36].…”

Difference in Cuticle Component and Immunocompetence in Nurse and Forager Worker Honeybee (Apis Mellifera L)

“…As is known, physicochemical properties of cuticle are highly affected by extraction method (Thomson et al 2004). The exoskeleton (cuticle) of insects varies widely in shape, biochemical properties and fuctions, which are inherent to the biological species, developmental stage, besides showing, wealth of architectural specialization and nuances in the different body regions (Elias-Neto et al, 2014).…”