Investigating the molecular basis of cleptobiosis in eusocial stingless bees (Apidae: Hymenoptera)

Cleptobiosis is a widespread strategy among animals in which members of one species raid for food or other valuable resources that were obtained by another species. Obligate cleptobiotic species are however rare, and the eusocial stingless bee Lestrimelitta limao features amongst these rare species. This bee pillages other stingless bee colonies. To provide some insights into the molecular basis and evolution of cleptobiosis in eusocial bees, here we compare transcriptomic data of foraging workers of the robber bee L. limao and three non-robber stingless bees: Nannotrigona testaceicornis, Scaptotrigona depilis , and Tetragonisca angustula . Our findings demonstrate that most of the orthologs identified as differentially expressed (DE) among the robber and the non-robber bees are downregulated in L. limao workers, showing a reduced expression activity in the cleptobiont during foraging. Several DE orthologs potentially regulate neuronal and synaptic activities in addition to other critical cellular functions. Additionally, differentially expressed orthologs associated with floral resource exploration and energetic metabolism were identified. These genes warrant further investigation to enhance our understanding of the specific molecular adaptations associated with cleptobiosis in eusocial terms.