An optimized protocol for cytogenetics in stingless bees (Hymenoptera, Apidae, Meliponini)

Cytogenetic studies in stingless bees date back to 1948 and have been useful to discriminate cryptic species and to infer the karyotype evolution in this diverse group of insects. However, a limitation of existing chromosome preparation protocols for bees is the lack of a cell suspension that can be stored for subsequent chromosome preparations. Therefore, the goal of this novel protocol was to obtain a suspension of dividing cells for each specimen allowing the analysis of an increased number of metaphase spreads per sample. This procedure was successfully applied to six species of Meliponini ( Melipona marginata Lepeletier, 1836, M. mondury Smith, 1863, M. scutellaris Latreille, 1811, Frieseomelitta flavicornis Fabricius, 1798 (black morph), Scaptotrigona sp., and Tetragonisca angustula Latreille, 1811), with the potential to yield up to six slides containing well-spread metaphase chromosomes per larva. Thus, this protocol may optimize the use of collected larvae by providing cell suspensions that can be stored for subsequent cytogenetic analyses and potentially adapted for other hymenopterans.