Feulgen Stain in Heterogeneous Egg Samples from Non-Synchronized Bradysia hygida (Diptera : Sciaridae) Laboratory Culture

In cultures of the sciarid Bradysia hygida Sauaia et Alves (Diptera : Sciaridae) the oviposition is asynchronous which hinders the grouping of individually collected embryo samples to be used in biochemical analysis and to correlate the data obtained with the predominant embryonic stage of this sciarid. Here we describe a Feulgen staining method that allows the staging of embryo collections of B. hygida. The analysis of Feulgen stained egg samples collected at different time intervals after oviposition (48-72, 72-96, 96-144 h) also led to preliminary information about the B. hygida embryogenesis. The blastula phase is attained 48 h after oviposition and the duration of the B. hygida embryogenesis is estimated to last between 8-10 days.