Abstract Stingless bees are key pollinators with high ecological and economic relevance, yet several species are currently threatened. This study aimed to develop and evaluate an accessible sperm cryopreservation protocol for the stingless bee Scaptotrigona bipunctata , addressing the lack of reproductive biotechnologies for these pollinators. Semen was collected from seminal vesicles and diluted in two extenders: extender 1 (NaCl, CaCl₂, KCl, and NaHCO₃; pH 8.7; 352 mOsmol/mL) and extender 2 (sodium citrate, NaHCO₃, KCl, and penicillin; pH 8.1; 280 mOsmol/mL). Samples were cryopreserved using a simple, non-programmable freezing method based on controlled cooling followed by liquid nitrogen storage. Fresh semen diluted in extender 1 showed higher motility (22.83 ± 3.38%) compared to extender 2 (10.85 ± 5.66%) and cryopreserved samples (CryoE1: 7.02 ± 4.54%; CryoE2: 8.63 ± 5.99%). Sperm viability decreased after cryopreservation but did not differ significantly between extenders (CryoE1: 57.73 ± 12.56%; CryoE2: 41.8 ± 9.94%). Mitochondrial activity remained unchanged across all groups. Although cryopreservation reduced motility and viability, mitochondrial function was preserved. This is the first report of sperm cryopreservation in stingless bees and provides an accessible tool to support genetic conservation strategies for these important pollinators.
Marques et al. (Mon,) studied this question.